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Forum Index : Microcontroller and PC projects : PicoMite 2X2 - an adventure in surface mounting. :)
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Mixtel90 Guru  Joined: 05/10/2019 Location: United KingdomPosts: 8304 |
At 46mm x 50mm it's smaller than 2"" x 2"", but it just didn't sound right. :) This should be fine for panelizing at 2x2 though, if you specify 4mm side holding strips. JLCPCB will assume 5mm if they do it, so it's a DIY job. It was getting a bit tight to shave another 1mm off without resorting to surface-mount MOSFETs, which I can hardly see, never mind solder. :(  This would probably be a good little project if you want to have a go at surface mount stuff. Most of it shouldn't be too bad, but you'd probably need a heat gun for the SD card holder. I looked at using a through-hole PicoMite but the end holes are too close to the edge of the board and I specifically wanted to stay within 50mm x 50mm. One pin on the GPIO port (A) does dual duty, it can be either VREF or RUN (the default) depending on the link. Power is via USB only. Resistors are all 1206 so will be easy to solder. The diode is a little bit smaller at SOD123. GP15 is used for a WS2812B LED. I left the 2R2 resistor for the SD card decoupling linked out. It can always be fitted if someone has problems. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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Rickard5 Guru Joined: 31/03/2022 Location: United StatesPosts: 463 |
I LOVE IT Please Release a construction pack, Although it would be nice to have though holes for the SDCARD Drive so you could run a cable to the SDCARD :) Edited 2022-07-21 11:21 by Rickard5 I may be Vulgar, but , while I'm poor, I'm Industrious, Honest, and trustworthy! I Know my Place |
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bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2971 |
Hi Mick, (The Other one) JLC wont need the edge strips proving you have at least 2 holes of 2mm dia. or larger to secure the board during manufacture. If they don't like the mounting holes they will add the strips themselves, you do not have to specify them. Just create your panels and define the V-groove and let the loose at the manufacture. Regards, Mick (the Fat one) PS. Nice board MBG Edited 2022-07-21 15:09 by bigmik Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 8304 |
How do you define the V groove, Mick? Just a line on layer O, or is it set when you choose the panelize option? Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 8304 |
@ Rikard Construction pack will be coming up, as will one for the PicoStick VGA. Sorry, no space to do that - the LED is right over the top of it anyway. You could hang a SD card off four of the GPIO pins instead though. Or you could just dab four wires onto the PicoMite pads. I'm trying to avoid SD card modules now. I know they are easy to use, but if supply dries up the board is a dead duck. Also, there are too many different designs and what one person has a draw full of another can't get at all. SMD sockets are dead easy to solder in the standard size and I'd rather use those if I have board space. They are also easy to get as they are manufactured for commercial purposes, not the hobbyist. The micro SD socket that I've been specifying (but haven't actually used yet) looks as if it'll be one of the easiest to solder in that size, although the easiest way will be to use hot air reflow with solder paste and flux. I'm not sure that even a fine tipped iron would be suitable, although it might work. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 8304 |
OK folks, the waiting is over. I've made a few enhancements: > All resistors are now on top of the board. > Pads under the board in the same sequence as a standard SD card. > Pads under the board from the Data Out pin on the WS2812B. > Pads and a diode under the board for optional external power input. > GPIO pin A can now be linked to the WS2812B input pin GP15. It can now be used for other things, but the WS2812B is unlikely to be of any use. Might be a useful option if it isn't fitted. Construction pack.zip EDIT: I had some inspiration. Here's a different set of gerbers, which have through-hole pads under TP4, TP5 and TP6. In theory, if some solder paste and flux is applied to the pads (pushing it through the holes) before mounting the PicoMite then heating the pad from underneath should cause the solder to reflow and make the connection. This brings the possibility of linking pin A to TP5 in order to play with the on-board LED. PicoMite 2X2 Gerber A.zip Edited 2022-07-24 20:20 by Mixtel90 Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2971 |
Hi Mick, All, DEXPcb does it automatically when I create the gerbers, I tick create panel and select number across and the number down to panelist and the gerbers have it added automatically. I think it is in the board outline layer but I will check one of my panels tomorrow for you. JLC do great prices for smaller boards so I don’t generally do panels and ve groove but if you want it as part of your design I can understand why. Mick. Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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