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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1056
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 12:02 am: | 
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Hi all,
I'd just like to judge the feeling towards producing construction articles that use fine pitch SMD processors.
Microchip do a fantastic processor, the PIC32, and I'd love to produce an article or two using one of them. The only problem is that the chips come in a 64 pin quad flat package with a lead spacing of 0.5mm.
The PIC32 come with on chip ethernet and USB host interfaces, which means you could connect devices like a cheap webcam to it. The opportunities for fun are limitless :o)
Soldering chips like these to PCBs requires some skill, and a decent magnifying glass as a minimum. (I use a professional stereo inspection microscope) There are different techniques for soldering QFPs, but learning how to do it could be expensive if you are footing the bill for the PCB and ICs.
What do you guys think?
Regards,
Mike. |
terrym
Frequent Contributor
Username: terrym
Post Number: 700
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 12:34 am: |
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I have no problems soldering these, so projects using them would be ok.
TM |
dave_squibb
Frequent Contributor
Username: dave_squibb
Post Number: 215
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 08:48 am: |
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Have a word with Microchip Mike. Manufacturers should supply "break out boards" for development rather than expect every potential user to design and make their own.
Alternatively could EPE (or someone like Magenta) supply a pcb with the QFP fitted and connections brought out to pads?
My old eyes are not up to these fine pitch devices any more although I would love to use them. |
johnmosborneuk
Valued Member
Username: johnmosborneuk
Post Number: 19
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 08:56 am: |
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I don't have a problem working with that pitch.
Maybe an article on how to work with fine pitch chips published along side your intended article would help other people to become more comfortable with the idea?
The PIC32 looks like an amazing chip and I can't wait for the PIC32MX ethernet demo board coming into stock so I can start playing with it  |
alanr
Regular Contributor
Username: alanr
Post Number: 26
Registered: 02-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 09:29 am: |
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At 75 I find my fingers are getting a bit twitchy, and good old 0.1 in. is fine enough for me. Pity. Another vote for Dave Squibb's suggestion of breakout boards. |
perro
Frequent Contributor
Username: perro
Post Number: 79
Registered: 10-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 09:43 am: |
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Mike,
I think that would be great fun.
I've tried soldering fine-pitch SMDs, with varying success. I use one of those flat circular lamps, with a 5 inch magnifying glass in the middle (sorry, I can't think of the generic term - it was about £22 from Maplin), and this makes it easy enough to see.
Sadly, even though I can see OK, the soldering results are variable. I'm lucky enough to have been given a hot-air station, but I have great trouble properly controlling/directing the heat (so risk damaging components). My most successful method is applying an excess of solder (shorting pins, in the process), then using de-solder wick to remove the excess. It works (just), but it never looks pretty & may take a few tries.
I'd love to get into SMT - there seem to be so many great SMD chips AND at a comparatively low cost (compared to DIP).
I agree, with John (above), and think it would be a great idea to do the project, but it would probably increase the take-up if EPE were to publish, along side, some SMD soldering tips, including, if possible, ideas on how hot-air stations should be used (not everyone's lucky enough to have one, but I'd love to be able to use mine to better effect).
Thanks, Mike, for putting the idea to the board. I really hope you decide to go ahead with this. |
joe
:::: Super User ::::
Username: joe
Post Number: 718
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 10:47 am: |
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The problem is that in the beginning, you can make several expensive mistakes with these parts whilst learning how to solder them, but we don't want that to provent us moving on and experimenting with all these new cool parts.
I would take a leaf out of Microchips experiment boards. Around the main SMD CPU, they drill holes for each pin so you can solder in high density PCB connectors. That way, you can either solder the IC direct or you can mount a piggy-back board that has the IC pre-soldered to it.
This makes the CPU removeable so has many advantages. For one, you can now reuse the CPU in different projects (or in revised versions of the same project), and if the CPU fails for any reason, you don't have the worry of trying to desolder it, and solder in the new one.
Joe
Read my ramblings - www.techbites.com/joe-farr
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alec_t
Frequent Contributor
Username: alec_t
Post Number: 147
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 12:01 pm: |
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Yet another vote for Dave Squibb's suggestion. Come on, Microchip, have a heart for us poor developers who don't have professional pcb fab facilities, 20/20 vision and the steady hands of a surgeon! For most projects we don't need a full development board: all we want is a PIC chip ready-mounted on a small pcb with all the legs brought out to pads/holes at a humanly-manageable spacing, e.g. 0.1 in, and at a price only just above the bare chip price!
Cheers, Alec |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 792
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 08:17 pm: |
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Could be interesting 
Is there a post missing here??
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1059
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 08:21 pm: |
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So, a small breakout board with the processor on it would be nice. A little like the inside part of this board, a microchip debug PCB:
I could probably arrange to have something like that made. Then I could do a design which can be made on veroboard, or a hand etched pcb, or a professional printed PCB. I could even arrange it so the professional PCB has an area for the CPU so that the CPU could be either hand soldered or one of these debug boards wired up to it.
Personally I'd prefer it if Microchip would listen to those of us who use their parts, and come out with a 40 pin DIL or SOP package.
I like the idea of the simple breakout board though. Any other ideas?
Thanks,
Mike |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1060
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 08:39 pm: |
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>Is there a post missing here??
Hi Jim,
no it was me, messing about. I've only just discovered how to insert images into posts. After 5 years on chatzone :o)
Mike |
dave_squibb
Frequent Contributor
Username: dave_squibb
Post Number: 216
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 08:45 pm: |
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Ideal Mike. |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1061
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 09:01 pm: |
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In the picture I posted above, the 'inner' pin pitch is 0.05", which makes it that little bit smaller, but harder to solder. I'll think about doing a board with 0.1" pitch. Then it could even be soldered to veroboard. |
andrew
Regular Contributor
Username: andrew
Post Number: 42
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 10:09 pm: |
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>I could probably arrange to have something like that made.
Sounds good!
I still can't believe I soldered that board myself :-) |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1062
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 10:23 pm: |
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>I still can't believe I soldered that board myself
Hello Andrew. I was expecting you :o) |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1063
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 10:49 pm: |
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In response to Alec, Microchip do a simple PCB as you asked for:
http://www.microchipdirect.com/ProductSearch.aspx?Keywords=MA320002
My problem is that I don't like it. It's just too big. So I'll go ahead with a small PCB and see where it leads.
Mike. |
phonoplug
Regular Contributor
Username: phonoplug
Post Number: 26
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 11:02 pm: |
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Hi All,
I would be prepared to make a board like this if there was enough demand, supplied with the SM PIC fitted. I mean like 10 or 20 people wanting to commit to buying it. It could be made to your design, Mike.
What does everyone think?
Alex |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1064
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 21 January, 2010 - 11:12 pm: |
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I'll be doing this myself thanks Alex, although the design will be published and you'll be free to do your own.
Mike |
alec_t
Frequent Contributor
Username: alec_t
Post Number: 151
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 12:05 am: |
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@mike
There's a big difference between $7.98 for the PIC alone and Microchip's asking price of $25 for the debug pcb with PIC already mounted! Hence the request for a SIMPLER pcb, such as the inner square shown in your image, with chip already soldered. Now that would be nice, with 0.1 in spaced connections to piggy-back on Veroboard or to use readily available headers, and just over 1 in square. A very versatile module for numerous projects, and hopefully a lot less than $25! I don't know how Microchip justify that price: I've just bought an SD card-reader, complete with card-socket, USB connector, 1 in square double-sided pcb, crystal, control IC and housing, all for the grand total of £1 retail in the local PoundShop!!
Cheers, Alec |
amr_bekhit
Frequent Contributor
Username: amr_bekhit
Post Number: 443
Registered: 06-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 12:11 am: |
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quote:Personally I'd prefer it if Microchip would listen to those of us who use their parts, and come out with a 40 pin DIL or SOP package.
I wouldn't bet money on it - they'd have to invest in various manufacturing costs to satisfy a relatively small number of hobbyists. It's a shame, but I guess that's business for you.
Great chip - I've done one design using them and just about to start a new one using their brand spanking new ethernet PIC32s. Definitely worth the effort of hand soldering!
--Amr
Helm PCB - My personal site.
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1065
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 12:14 am: |
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It's all about volumes, Alec. Microchip will not sell many of these boards, maybe a few thousand. That SD reader was probably manufactured in significantly higher volume.
I saw a digital camcorder in a shop last weekend. It had a 1.5" colour LCD too, and cost £25. Even though I'm experienced with this kind of low cost high volume manufacturing, my jaw dropped :o)
It would be poor quality though and I wouldn't want to waste my money on one, but you have to marvel at how they achieve it. |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 793
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 05:27 pm: |
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That explains it Mike 
on a serious note, I think it would be a brilliant project, and possibly a lot of interest.
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1066
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 05:45 pm: |
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Good. So long as EPE are happy with the concept, I'll give it a go.
I've just received samples from Microchip ( thanks guys! ) of the new PIC32 processor which has an on-chip Host USB interface and a high speed ethernet interface. I'm sure there will be something interesting we can do with that lot!
Mike |
istedman
Frequent Contributor
Username: istedman
Post Number: 154
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 08:11 pm: |
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Mike,
I would be interested in a board with the PIC32 device. They are the new ARM core based PICs?
What specific device are you evaluating?
As an idea, look at the FTDI FT2232HQ mini-module, Farnell code, 1697465. Just done some quick pricing on a representative PCB, can be done for less than £8 with the components assembled (assuming you free issue the PIC32 to the assembler). The PCBs would be about £4 each in a batch of 50. |
amr_bekhit
Frequent Contributor
Username: amr_bekhit
Post Number: 445
Registered: 06-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 08:12 pm: |
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@istedman: The PIC32s are based on the MIPS M4K core, not ARM.
Helm PCB - My personal site.
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alec_t
Frequent Contributor
Username: alec_t
Post Number: 155
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 08:43 pm: |
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At the risk of being flamed for mentioning a non-PIC device, Texas Instruments sell a set of 3 target boards each with an MSP430F2012 (a 16-bit 14-pin processor) mounted and connections at 0.1 in pitch, for $10. If they can do it at that price, surely Microchip could offer something similar for the PIC.
Regards, Alec |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 794
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 09:32 pm: |
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There would be an ocean of difference between a 14pin and a 64 pin chip Alec.
I just had a mess about with eagle, and for a 0.1 layout you would require a ~2 in board. thats without anything other than the chip itself on board. ( although there is some room available. ).
This is an example , i tried double sided also but it only introduced Via`s,( to be avoided)
Its not tidy, but it does show the requirments for a .1 in layout I think.
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 795
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 09:37 pm: |
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Incidently, What does this mean?
"(assuming you free issue the PIC32 to the assembler)"
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1068
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 09:40 pm: |
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Unsurprisingly Jim, what you did there looks strikingly similar to what this guy did:
http://bytewerx.blogspot.com/2009/06/interfacing-usb-webcam-to-pic32.html
I'm leaning more in the direction of 0.5" pitch now, similar to the picture in my post above.
This is half the fun, finding a compromise solution to a problem.
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 796
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 09:40 pm: |
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Ok Shoot me
I was thinking assembler language 
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1069
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 09:42 pm: |
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>I was thinking assembler language
lol. Me too first time I read it. I wasn't so hasty with the 'Post' button though :o) |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 797
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 09:44 pm: |
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Thanks for the link Mike. It was only an example to show how much space is required for the .1 in layout
.5" now thats a thought 
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1070
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 22 January, 2010 - 10:44 pm: |
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>.5"
Duh!
should be 0.05"
Thanks Jim :o) |
joe
:::: Super User ::::
Username: joe
Post Number: 720
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 07:02 am: |
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This guy on Ebay is selling blank and populated converter boards.
http://stores.shop.ebay.co.uk/Stella-Collectible-and-Electronics_ELECTRONICS-PRODUCT_W0QQ_fsubZ835572010QQ_sidZ204230890QQ_trksidZp4634Q2ec0Q2em322
A board with a dsPIC33FJ256MC710 mounted costs around £12 + postage. He's also got blank boards without the PIC for just a couple of quid.
Joe
Read my ramblings - www.techbites.com/joe-farr
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alec_t
Frequent Contributor
Username: alec_t
Post Number: 156
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 11:09 am: |
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Nice effort, Magnum4. Even at 2" square a board like that would have its uses. However, following Joe's link shows it's also possible to re-arrange the row of pins at each edge into two smaller rows, thus reducing board size :-
The above looks ideal, if it were available with a PIC32 already mounted.
Cheers, Alec |
joe
:::: Super User ::::
Username: joe
Post Number: 721
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 11:17 am: |
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"The above looks ideal, if it were available with a PIC32 already mounted."
It is. The same chap has them.
http://cgi.ebay.co.uk/MCU-BOARD-PLUG-IN-MODULE-MICROCHIPS-PIC32MX460F512L_W0QQitemZ270511540679QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efbbe89c7
Read my ramblings - www.techbites.com/joe-farr
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davejs
Just joined
Username: davejs
Post Number: 5
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 12:31 pm: |
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Just as an aside, I've used other modules from this manufacturer, bought via Futurlec, and they've all been of good quality. |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 798
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 06:27 pm: |
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Hi lads.
Alec_t Thanks.
The chip Mike asked about was a 64 pin, the above are 100 pin, also they are the same size as my board, 51mm square. This size is needed for .1" pitch.
the 64 pin could be accomadated on a board with a couple of double row connectors, and a small size reduction could be made.
the advantage of using 2 double connectors, would be that the .1" pitch is easy to solder, it could be used with vero but not by plug in board. The .05" cannot be as easily used.
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 799
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 07:19 pm: |
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just had another quick stab with Eagle.
this board is 30x50mm. It has a ground plane top and bottom.
One track not routed, but that is easy to fix. the box headers are used really only for their pads.
Its all academic anyway until Mike lets us in on the chip in question 
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1071
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 10:01 pm: |
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That's good Jim, a nice size too. Is that the 64 pin part?
I'll try to drop you a processor type soon. By the looks of things though it should be suitable for a large number of parts. If push comes to shove, you don't need to have a clean pin to pin mapping. Do keep it up!
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 802
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 10:19 pm: |
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Yes Mike 64 pins.
Ill do some more tomorrow, if Im sure its a 64 pinner your aiming for
Off to pub now for a few
Cheers.
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1072
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 23 January, 2010 - 11:29 pm: |
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Yes, it's 64 pins. The 100 pin modules shown above are, to my mind at least, just a bit too big to be the basis for a plug in module. I'd like to keep it small. So what you're doing Jim looks good.
Mike |
joe
:::: Super User ::::
Username: joe
Post Number: 722
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 08:46 am: |
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Jim,
The only problem I can see with your design, and this may or may not be an issue, is that you can't use it with a breadboard as is.
You could of course make another adapter board that the CPU card plugs into.
Read my ramblings - www.techbites.com/joe-farr
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joe
:::: Super User ::::
Username: joe
Post Number: 723
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 09:00 am: |
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In fact, you could do a standard DIP layout with some advantages; foot-print unfortunatly isn't one of them. But it will fit in a breadboard or on Vero Board if needed, so dosn't preclude those people who don't etch their own project PCB's; they still need the carrier PCB of course.
Joe
Read my ramblings - www.techbites.com/joe-farr
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1073
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 10:53 am: |
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I don't see why Jim's design is a problem - it would fit on square pad matrix board. It will be interesting to compare the two options for size though.
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 803
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 11:26 am: |
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Hi Joe,
Yes I had considered a Dip layout. However its around 4 inches long!!!
I realised my layout wouldnt be useable with breadboard( see post above) but would be useable with all other forms
Nice board by the way
Regards,
Jim
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joe
:::: Super User ::::
Username: joe
Post Number: 724
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 11:28 am: |
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Mike,
Jim's design isn't a problem at all and is quite compact, and yes, it will fit most types of 0.1" solder prototype board.
When I said breadboard, I was referring to the plug-in prototyping boards.
Joe
Read my ramblings - www.techbites.com/joe-farr
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741
Frequent Contributor
Username: 741
Post Number: 122
Registered: 08-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 01:26 pm: |
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Hi Magnum4, joe
Those PCB layouts look nice..
Is there any chance of posting up the relevant Eagle files (.brd, .sch) please? |
joe
:::: Super User ::::
Username: joe
Post Number: 725
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 01:34 pm: |
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@741... Eagle (Make's sound of a hissing snake)
I personally use DipTrace... you can download a free version from www.DipTrace.Com that will allow you to open / edit this file. You can use the freeware version for this file.
Read my ramblings - www.techbites.com/joe-farr
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1074
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 04:12 pm: |
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Eagles my favorite so suits me.
The part I had in mind is PIC32MX795F512H-80I/PT
Regards,
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 804
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 04:17 pm: |
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Bang me an email Stephen, Ill send them on.
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 805
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 04:42 pm: |
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Had a longer ( much longer) Play with eagle.
This is a single sided board, ground plane and 32x44 mm. 
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 806
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 04:46 pm: |
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By the way, the routing size is 7mil, Omilex wont do below 8mil.
Pcbcart will though.
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1075
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 04:59 pm: |
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That's a great size Jim. Where were the 7mil issues? I've had olimex print boards with that pitch chip before, so I assume I managed to make 8mil.
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 807
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 05:06 pm: |
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Sorry Mike, I misread it. Boards with less than 8mil longer lead time
I was wondering actually as the pad spacing is 7mil
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1076
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 05:46 pm: |
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Olimex say that boards with less than 10mil take longer; their lower limit is 8mil.
I'll take a look at the PCB later though - I just remembered I have to recreate a case for EPE tonight.
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 808
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 08:31 pm: |
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Ok it was the ic package i was using. Ive downloaded a new one and it does pass the 8mil DRU.
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1077
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 24 January, 2010 - 11:52 pm: |
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Slight correction to the part number - It's the PIC32MX675F512H-80I/PT.
Half a megabyte of flash. How could we possibly fill all that :o) |
zeitghost
Frequent Contributor
Username: zeitghost
Post Number: 1420
Registered: 01-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 25 January, 2010 - 08:19 am: |
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"640k should be enough for anyone".
ROTFLMFAO. |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1078
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 25 January, 2010 - 08:29 am: |
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>"640k should be enough for anyone".
Getting close then! :o) |
alec_t
Frequent Contributor
Username: alec_t
Post Number: 160
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 25 January, 2010 - 09:15 am: |
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Hi,
That latest pcb looks great, Magnum4.
Folks, faint bells are ringing.
Elsewhere in the CZ I seem to recall one or two reports of problems getting the internal oscillator of a chip to work reliably, e.g. with a quartz resonator as distinct from a crystal, and of the need to place loading caps as close to the chip as possible. So clearly the oscillator can be pernickety. Is crystal/capacitor positioning, or trace inductance/capacitance likely to be a problem with the above (or the commercially available) adaptors? If so, is there a work-around, or would an external oscillator be necessary?
Regards, Alec |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1079
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 25 January, 2010 - 09:14 pm: |
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It's always important to follow careful design guidelines when wiring up a crystal, especially low power oscillators. Let's just say I wont be building a 1000 of these boards before testing it thoroughly :o)
Simple answer is I don't know. I doubt the 32KHz oscillator will function, but I see no reason why a 4 - 8MHz crystal should not work if one takes care on the layout of the board it connects to. I'd rather not go for an oscillator module - they are expensive and draw unnecessary current.
Mike |
johnmosborneuk
Regular Contributor
Username: johnmosborneuk
Post Number: 24
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 25 January, 2010 - 09:26 pm: |
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Maybe the PIC module could have the programming header, oscillator and decouppling capacitors on it which might make it easier to ise the module on other designs? |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1082
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 25 January, 2010 - 09:47 pm: |
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It's worth a thought, certainly. They could be tracked out even if not actually populated. The only downside is an increase in the cost of the PCB, for going to double sided. Will bear it in mind though, thanks.
Mike |
mark
Frequent Contributor
Username: mark
Post Number: 98
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 11:41 am: |
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Mike,
Magenta would be happy to get boards made with the SM parts fitted, but the question is one of numbers. Set up charges for a run of boards can be about £100, then incoming carriage, then another £150 for a solder paste mask for the chip. In the 'old days' a good magazine project would sell hundreds in the first few months, today it's so few that £250 set up costs are risky. The problem is that this then makes the project seem expensive - look what hardware you can get for £30 in PC world! We'd love to support more projects, but the numbers just aren't there any more. |
echase
Frequent Contributor
Username: echase
Post Number: 277
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 01:38 pm: |
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That eBay PCB is extraordinarily cheap at £4 inc P&P compared with any other from Farnell, RS etc. Even EPE charge £6 minimum for a PCB and more for double sided. There is also a 64pin one from them for less money. http://cgi.ebay.co.uk/SMD-CONVERTER-ADAPTER-PCB-TQFP64-Convert-4x16-PIN_W0QQitemZ270511682101QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efbc0b235
Why reinvent one? Just negotiate a good price for a batch. Does not solve the potential crystal problem though. But if Microchip's MA320002 - PIC32MX USB PIM PCB works without a crystal on it surely others can get similar to work.
(Message edited by echase on 26 January, 2010) |
joe
:::: Super User ::::
Username: joe
Post Number: 728
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 02:11 pm: |
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@echase
but unfortunatly, it dosn't address the problem of soldering the fiddly blighters, which was the original concern.
Looking at your Ebay link, these boards are from the same supplier as the ones I found (see above), just a different looking quality or maybe old stock, I don't know.
I'm tempted to drop these guys an Email and ask if they can supply these boards with the PIC32's were interested in pre-mounted (they offer other PIC's so why not) and see what happens... they can only say no but if they can, even with postage I bet they would be cheaper than a DIY solution; and cost will always be an issue for people.
As for the off-board crystal concern, I think this may be a bit of a red herring. I've used my own PIC carriers with external crystals on plug-in bread boards with no problems running at 20MHz, so should be even better on a PCB with soldered connections.
Read my ramblings - www.techbites.com/joe-farr
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echase
Frequent Contributor
Username: echase
Post Number: 278
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 02:28 pm: |
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Futurlec also stock those, including 2 sizes of 64 pin board for around $1. And as you say one of these suppliers may be willing to mount the chips for you. |
alec_t
Frequent Contributor
Username: alec_t
Post Number: 163
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 04:29 pm: |
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Mike, you sayn"I doubt the 32KHz oscillator will function, but I see no reason why a 4 - 8MHz crystal should not work". Joe confirms he can get a 20MHz clock to run.
I'm rather surprised it's this way round; I would have expected the lower frequency (32kHz) to be less affected by stray capacitance/inductance.
Can you give a reason why the 32kHz clock is less likely to work? A shame if that's the case, as a couple of projects I had in mind need a real-time clock.
Regards, Alec |
phonoplug
Regular Contributor
Username: phonoplug
Post Number: 31
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 04:40 pm: |
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I suspect the reason for a 32kHz clock being more sensitive is because the 'watch' crystals used are very low power. As a result, they have very small load capacitors, so stray capacitance will have more of an effect. |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1083
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 26 January, 2010 - 11:10 pm: |
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In my experience the low power & low frequency oscillators are very picky about track routing, for the reasons phonoplug mentions.
To Joe and others, I would be looking for a reliable source. ie, an existing open source supplier. If the supplier is happy to provide full cad files that can be published, then fine. Otherwise I'm not interested. Not because I'm an open source nut ( I'm not ) but because, as I mentioned earlier, I am not prepared to invest the effort in producing designs if a key component supplier decides to cease supply. I've been bitten by this before, and I hated it.
Besides, it's more fun when other people on the forum join in!
Mike. |
joe
:::: Super User ::::
Username: joe
Post Number: 729
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 04:57 am: |
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Mike,
A DIY solution like this is going to be more expensive that using off the shelf parts and suppliers. Sure, you run the risk of a supplier going out of business, but whats the alternative.
Are you saying that YOU are going to make / source a stock of carriers with pre-mounted PICs and then resell them. What if you stop doing that?
EPE don't sell parts for projects (once the PIC is mounted it's really a part I guess), and they eventually run out of PCBs. Certainly once a project is quite old they don't bother re-ordering PCB's.
The original requirement was to have a carrier with a PIC pre-mounted, so having PCB foils available isnt going to help the guy in the street. Sure, he can make the board but he's still got to mount the PIC.
Actually, if they are capable of making a PCB, they are capable of either making a suitable carrier or redesigning the layout of the main projct PCB to accept whatever carrier is available.
Microchip sell that PIC for around £8.75, +VAT and carriage (drops to around £8 if you order 26+ CPUs).
Ordering 25 PCB's from PCB pool made to Magnum's design costs around £3.20 (There may be postage costs and sales tax on that, I dont know)
Cost of connectors, a couple of decoupling capacitors, say £1.
Then theres the cost of having the PIC & rest of the components mounted which I have no idea on. But let's say you can get some company in the back of beyond to do the work for £5 a board in such low quantities. Add in additional carriage costs.
Your looking at around £20 - £25 minimum per board but I can see it being more than that.
Next you have to test each board and be prepared to offer refunds / replacement boards if somebody complains that the board was DOA.
I can see why Magenta don't think the numbers stack up and why Microchip charge so much for their boards.
Add in additional costs if your going to mount xtals and ICSP connectors etc.
It would be foolish not to at least investigate with one or more companies about the possibilities of them offerering the requried PIC pre-mounted, especially when they are already offering the required carrier boards but with just a different PIC model. In theory, there are no additional re-tooling costs for them; just the effort and CPU cost differences.
You've had a lot of forum involvment in this subject. Lots of different ideas kicked around and cool suggestions floating to the surface, and I personally don't see anything wrong "IF" the outcome is that it's cheaper to just find a supplier who will do this for a fraction of the cost.
What's important I think is that people have access to this new PIC technology in an affordable way.
Joe
Read my ramblings - www.techbites.com/joe-farr
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zeitghost
Frequent Contributor
Username: zeitghost
Post Number: 1425
Registered: 01-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 10:58 am: |
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I remember the joy of getting a 4060 to run a 32kHz watch crystal for a student project.
He had no chance, and it took me ages to get the damn thing stable.
It would either not start or alternatively slowly die.
Great fun.
Not. |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1084
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 02:46 pm: |
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@Joe,
I'm moving towards the boards offered on ebay. I'll try to contact the person/company selling them, as I'm still nervous about supply drying up.
I take your point about costs; I'd calculated about £2 per board from Olimex in bulgaria, and was going to offer the soldering for a nominal sum.
As we could simply re-implement the carrier board should supply dry up then I guess it's a low risk approach.
I'll have a chat with them and see what happens.
Mike |
echase
Frequent Contributor
Username: echase
Post Number: 284
Registered: 07-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 04:25 pm: |
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Mike I am probably going to do a futurlec order soon. I’d be happy to add an adapter pcb from http://www.futurlec.com/SMD_Adapters.shtml and give it to you for free as $1 is not going to break the bank. It’s the same part as the ebay one. Or you could try the original source where a PIC32 device on this adapter pcb is 460 baht or £8.50. But not sure what quantity that is for see http://www.etteam.com/product/06000PIC.html
They look like a reasonably stable source. |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 809
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 08:00 pm: |
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Hi Guy`s.
A lot depends on the volume of boards, The layout above could be sourced fairly cheap, No components fitted.
The board above is prob not useable as it stands, but it is close.
I could probably have a batch made at around the 2 pound mark,( bare board), plus postage.
On their way Stephen.
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 810
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 08:07 pm: |
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@ John.
"Maybe the PIC module could have the programming header, oscillator and decouppling capacitors on it which might make it easier to ise the module on other designs?"
This depends on what Iscp connector your using, The icd2 is different than the pickit I think??
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1085
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 08:22 pm: |
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Hi Jim,
>I could probably have a batch made at around the 2 pound mark,( bare board), plus postage.
Would that include solder resist and silk screen?
Mike |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 811
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 08:26 pm: |
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Yes Mike. I think so
Ive sent you some details
Regards,
Jim
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johnmosborneuk
Regular Contributor
Username: johnmosborneuk
Post Number: 29
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 08:41 pm: |
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@Jim
Thats true enough, the pickit 2 uses a 6 pin straight header and the ICD2 uses a 6 pin RJ11 but they follow the same pin sequence i.e 1-1, 2-2 and microchip do make an adaptor to connect the ICD2 RJ11 cable to a pickit2 header so the standard 6pin straight header would be best (and cheapest). |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 812
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 08:53 pm: |
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Does the Pickit3 follow this layout?
Regards,
Jim
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johnmosborneuk
Regular Contributor
Username: johnmosborneuk
Post Number: 30
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 09:35 pm: |
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Pickit 3 has the same connector as pickit2 |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 813
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 09:41 pm: |
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Probably worth following then
Regards,
Jim
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1086
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 27 January, 2010 - 09:53 pm: |
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@ Mark
Hi Mark, I appreciate your comments, and completely understand. Given the low numbers I'm still thinking of offering to hand solder the chips for people, and charge a nominal fee for doing it. It depends what comes back from the Thai company others have mentioned.
I just looked them up - in one of my previous jobs I used to stay just down the road from them in Bangkok, probably been in their shop at the weekends. Small world! |
hackinblack
Frequent Contributor
Username: hackinblack
Post Number: 443
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 28 January, 2010 - 11:41 am: |
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these should fit the bill,maybe?
the price is cheaper than sending for a small batch of DIY pcb's
http://www.mikroe.com/en/tools/emptymcu/pic2433/lv2433/ |
atferrari
Frequent Contributor
Username: atferrari
Post Number: 821
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 28 January, 2010 - 12:04 pm: |
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I wonder how do you apply, in a common breadboard, those double rows of pins, with 0.1" spacing shown in the different examples of adaptors. Or the breadboard is not used at all here...?
In my ignorance and imagination, the sole thing that made sense was something like shown by Joe: long single rows of pins duly inserted in my 15yo breadboards.
Not having experience at all here (other than welding with quite poor results, once, a small IC) I guess if I am missing the boat altogether.
Agustín Tomás - Buenos Aires - Argentina
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joe
:::: Super User ::::
Username: joe
Post Number: 730
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 28 January, 2010 - 01:01 pm: |
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Agustin,
I, like you, use plug-in breadboards for prototype work and these square boards won't be any good for this. I personally would have preferred the long DIP arrangement, but I can see both sides of the issue.
The DIP layout would be around 4" long (10 cm) and so is quite a lot of space and this seems to bother some people. It would also probably work out more expensive for the PCB, especially when you look at the boards that echase found are professional PCB's for around $1 each.. an amazing price. I've actually ordered a batch of these boards so thanks for finding them echanse
Anyway, once the final board design has been settled on, it will be a simple matter to design a basic carrier board that can accept the PIC PCB board and allow it to fit onto a standard breadboard. If the PIC board dosn't have an ICSP / Crysyal etc on board, these can be added to the carrier board to make a nice plug-in module.
I gave up prototyping on vero / matrix board years ago and I'm not going back now.
Joe
Read my ramblings - www.techbites.com/joe-farr
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mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1087
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, 28 January, 2010 - 07:44 pm: |
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@hackinblack
They appear ok, £3.62 each. Then shipping is £16.
Not so nice now!
The kind of projects that would be based on the PIC32 will include ethernet and usb interfaces. They are just not the kind of projects that are going to suit themselves to plug-in breadboards.
My aim would be to produce designs that could have a practical use for people, and would result in the PIC board being fitted or soldered to a PCB that could be etched by those who are interested.
There are some interesting opinions coming out in this thread ( I did ask! ) and it almost looks like there might be two approaches that would be of interest - a DIL version for those favoring breadboarding, and a smaller one that would allow compact PCB design.
I've no personal motivation to make a four inch long daughter board, but if that's the prevailing opinion I might still go with it. If the Thai company can supply cheap boards with the processor already fitted and with a fair delivery cost, then that would get my vote at the moment though. |
hackinblack
Frequent Contributor
Username: hackinblack
Post Number: 444
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 29 January, 2010 - 08:04 am: |
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ouch that post price is way OTT the former yugoslavia is after all now in the EU
i would have thought more like a £3-4/E for something that will go letter post
guess an easypic5 wont be winging its way here until the lottery win
a breadboard will handle USB and ethernet speeds (with compact layouts)but a 4" long DIL footprint is a bit of a retrograde step
the nature of the IC is steering everyone towards PCB production for the whole board;why not go the whole hog and produce a 'general purpose' mini board with the outputs on SIL/DIL headers? it may then be possible to build a working project with minimal extra circuitry
if a cheap source of multi-way sockets such as the simm sockets used on the simstick designs was available it could from the basis of dozens of 'modular' projects based on a common edge connector pinout,or stack'em like the arduino shields? |
alec_t
Frequent Contributor
Username: alec_t
Post Number: 168
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 29 January, 2010 - 02:09 pm: |
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It's now clear, from the above posts, why Microchip don't offer 64-leg (or higher) devices in DIP packages!
Alec |
joe
:::: Super User ::::
Username: joe
Post Number: 731
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, 29 January, 2010 - 02:13 pm: |
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But if they would offer the fiddly blighters in PLCC packages, we wouldn't have all these problems
You can get nice sockets for them and they are dirt cheap.
Joe
Read my ramblings - www.techbites.com/joe-farr
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atferrari
Frequent Contributor
Username: atferrari
Post Number: 824
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 30 January, 2010 - 02:20 am: |
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Hola Joe,
it will be a simple matter to design a basic carrier board that can accept the PIC PCB board and allow it to fit onto a standard breadboard.
Even more at lost now. Could you elaborate? Sorry but I am a real ignorant. From the $1 PCB found by echase how could I go to a breadboard?
Any picture that could bridge my eventual difficulties with (electronics) English?
After a bad experience soldering an ill fated smd IC with not very steady hands, I am scared of all that!!
Agustín Tomás - Buenos Aires - Argentina
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 814
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 30 January, 2010 - 07:17 pm: |
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Hi Agustin,
Hard to put in words. If you have the carrier board as described above, you would need another board to convert the square layout into a DIP layout, similar to Joe`s post above, However those boards are still .05" pitch so are that bit more difficult to solder.
@Joe, the first thing I did when Mike posted the part number was to see if ir was available in PLCC, Its not.
This was the way I went for myself. For the 874/877 and the 452.
I brought all I/O out to boxheaders, and then to the breadboard.
Ill post a pic or 2.(Pun noticed)
A module would be my first preference, however if the chip gets damaged then its a major job to change,in TQFN package, and I dont know about anyone else, but I have blown a few pic`s.
The above layout CAN be used for breadboard, by using 1 row of straight pins per side it can be plugged into breadboard, and one row of angled pins to take I/O to other parts of the board.
Or a idc connector can be made to go out to a 32 pin connector, this does however defeat the idea of keeping the whole thing compact.
One other point to watch out for is that not all 32`s have the same pinout, I have not checked yet, but it could be a problem with Vdd and Vss coupling capacitors!!?? ( May well be wrong on this)
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 815
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 30 January, 2010 - 08:32 pm: |
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This is the "Unprofessional board"
Unpopulated 
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 816
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 30 January, 2010 - 08:36 pm: |
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This is the Plcc Board Populated. |This one runs at 20Mhz, and no problem so far anyway
this is why I like the Module type, blow a chip, and pop in a replacement.
Regards,
Jim
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magnum4
Frequent Contributor
Username: magnum4
Post Number: 817
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 30 January, 2010 - 09:13 pm: |
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This is a comparison with a 40 pin 877.
Will give an idea why compact is so nice I think.
Regards,
Jim
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atferrari
Frequent Contributor
Username: atferrari
Post Number: 825
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 30 January, 2010 - 11:44 pm: |
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Well, in my case, buying the PICxx board, even already populated, would not solve anyhting on account of the PCB required afterwards.
It seems that I should solve my lack of dexterity on all this first. 
Agustín Tomás - Buenos Aires - Argentina
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alec_t
Frequent Contributor
Username: alec_t
Post Number: 171
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 31 January, 2010 - 07:43 pm: |
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Regarding the 32kHz oscillator, does the PIC32 series have any built-in caps like the MSP430F2013 from Texas Instruments? [I know, I'll get flamed again for deviation from the PIC path of enlightenment!]
Quote:
"The LFXT1 oscillator supports ultralow-current consumption using a 32,768-Hz watch crystal in LFmode(XTS = 0). A watch crystal connects to XIN and XOUT without any other external components. The software-selectable XCAPx bits configure the internally provided load capacitance for the LFXT1 crystal in LF mode. This capacitance can be selected as 1pF, 6pF, 10pF or 12.5pF typical. Additional external capacitors can be added if necessary."
TI also give some guidance applicable to low-frequency oscillators in general.
Quote:
"Low-frequency crystals often require hundreds of milliseconds to start up, depending on the crystal. Ultralow-power oscillators such as the LFXT1 in LF mode should be guarded from noise coupling from other sources. The crystal should be placed as close as possible to the MSP430 with the crystal housing grounded and the crystal traces guarded with ground traces."
But I expect you guys knew that already!
Regards, Alec |
zeitghost
Frequent Contributor
Username: zeitghost
Post Number: 1429
Registered: 01-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 01 February, 2010 - 08:18 am: |
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The HD6303 layout guide gave instructions to avoid traces crossing the tracks to the crystal.
And that was for a 4MHz xtal... 32kHz xtals are a different kettle of fish. |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 819
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 03 February, 2010 - 06:44 pm: |
|
Just Grabbing the 100th post
Regards,
Jim
|
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1093
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 03 February, 2010 - 08:07 pm: |
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lol. And are you going to post another 200 times to get your one thousandth post? |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 821
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 03 February, 2010 - 08:11 pm: |
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Hmmmmm. Now thats an Idea 
Regards,
Jim
|
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1094
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 03 February, 2010 - 08:23 pm: |
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What do you use that PCB for Jim? |
magnum4
Frequent Contributor
Username: magnum4
Post Number: 823
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 03 February, 2010 - 08:41 pm: |
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Its Basically my prototype board Mike. i develop the project on breadboard, connected to this "master ". than I build the other circuit and plug into this board.
Might not be the most efficent, as i often have spare I/O, however it works for me.
Regards,
Jim
|
staceyfinn
Just joined
Username: staceyfinn
Post Number: 4
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 07 February, 2010 - 10:16 am: |
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I'd like to see some PIC32 projects. The small lead pitch is fine. Dino-Lite do a good led lit microscope for around £50. |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1102
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 08 February, 2010 - 08:40 pm: |
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Thanks for all the comments. I'll try to put something together in a few months time.
Mike |
hackinblack
Frequent Contributor
Username: hackinblack
Post Number: 457
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 10 February, 2010 - 07:49 pm: |
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this link is a UK company selling adaptor boards
for PIC and AVR,available WITH the chip pre-soldered in place...
http://www.mikromate.com/microchip-64-pin-adapter-boards-13-p.asp |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1108
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 10 February, 2010 - 08:23 pm: |
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Hum, very expensive. £22 with a PIC32 chip. It's probably a fair price when done in low volumes though. They do, after all, want to make a profit.
Mike |
hackinblack
Frequent Contributor
Username: hackinblack
Post Number: 458
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, 10 February, 2010 - 09:12 pm: |
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that's the rub 'low volume'
they either have to make their money on the first few sold;
or hope they don't sit gathering dust,on the shelves THEY are paying for
though with experimenters paying hundreds of pounds for robotics bits,maybe the market can afford it...? wish i could! |
mikeb
Frequent Contributor
Username: mikeb
Post Number: 240
Registered: 02-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 13 February, 2010 - 11:03 pm: |
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Very interesting discussion.
I use Futurlec (v cheap - 2 weeks to arrive from the Aussies). I have played with the 24FJ and the PIC 32. The 24FJ I bought from Microchip mounted onto a carrier board that is intended for their Exploroer board.
I had no touble just hooking a 20MHz crystal up.
Soldering the 100 pin TQFP (which stands for The Quick way to bugger up your sight Flat Pack) jobs are now beyond me.
Nice one Mike - you get my vote.
rgds
mb |
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64 Pin Carrier PCB Foil - DipTrace format
