SAMD21G18A Breakout Board

Details

This project started after my first introduction to PCB design at my 2019 summer internship. At that internship, I designed a board that used a SAMD21 to control a GPS and LoRa module. This was my first introduction to the SAMD21 MCU and I immediately was interested in its capabilities. As a side project to work, I started to design a development board centered around this module.

Files

samd21-board-KiCad-files-V1.zip

KiCad design files for Rev1. This has been assembled and tested to verify it works. Definitely improvements to be made

x-zip-compressed - 270.46 kB - 01/08/2020 at 20:05

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samd21-board-GBR-V1.zip

.GBR files for Rev1, with existing silkscreen problems

x-zip-compressed - 116.97 kB - 01/08/2020 at 20:05

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Project Logs

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Revision 1 Assembled and Programmed with Success!
sirmylesavery • 01/08/2020 at 19:58 • 0 comments

I spent a couple hours today and yesterday attempting to assemble Rev1 of this board. The two board components that were extremely difficult to do by hand without the proper microscope for viewing were the microUSB port and of course the SAMD21, which in the 48-pin TQFP package was very difficult to do without jumping pins together with solder. All the other components, all 0805 handsolderable footprints with 1 crystal, reset button, and voltage regulator, were easy to assemble.
The next stage in assembly was to upload the bootloader to the SAMD21. I did this by following a great tutorial from Adafruit titled: How to Program SAMD Bootloaders. After fixing some connection issues, I finally managed to upload the bootloader to the SAMD21. After booting up the Arduino IDE and uploading the basic blink sketch, I can verify that it works! I'm very happy about this, given the amount of time I invested into the design and assembly.
Attached below are some photos of the assembled board, both powered and unpowered.
Blank PCBs Ordered and Arrived
sirmylesavery • 01/08/2020 at 19:43 • 0 comments

Back in October of 2019, I ordered a set of blank PCBs from JLCPCB. I choose the slow shipping option and they finally arrived in November. At the time, I did not have the components or tools to assemble these boards, so that had to wait. Attached below are some photos of the blank PCBs. You can see some of the silkscreen problems identified from the design files. Other than that it looks pretty good.
Components Selected
sirmylesavery • 01/08/2020 at 19:34 • 0 comments

Components have been selected. There are available here from Octopart. Coming in at a cost of $10.93/per board components, it is pretty reasonably priced for what the SAMD21 is capable of.
Revision 1!
sirmylesavery • 01/08/2020 at 19:31 • 0 comments

I designed revision 1 back in October of 2019. It was relatively quickly designed, so there are some silkscreen problems. These will be fixed in future version. Attached are some images of the designed board.