Geoffrey Makes Anything

# Week 6 ## Electronics Production ### Group Assignment > characterize the design rules for your in-house PCB production process The ideal is to not have any traces that are below 0.02 of an inch. From recitation last week, Quentin said to have 0.4 mm or 1/16th of an inch minimum, so I went with that for the board design last week. As we can see from the test made by [Ayah Mahmoud](https://fab.cba.mit.edu/classes/863.25/people/AyahMahmoud/), the machine cannot create gaps between traces for anything below 0.02 inches. Note that it can still machine traces individually until about 0.01 inches of thickness. | ![Boad Milling Precision Test](images/251012-Board-Precision-Test.jpg) | |:---------:| | *Closeup of precision test made by Ayah* | > submit a PCB design to a board house ### Individual Assignment > Make and test an embedded microcontroller system that you designed I used the Modela SRM-20 to mill my PCB. Gert kindly helped me get set up, and I followed the [archshops tutorial](https://archshops.mit.edu/modela.php) to use the machine which is comprehensive. | ![Setting up the trace cut file in mods](images/251015-CNC-Mill-Setting-Up-Mods.jpg) | ![You press the bit gently down into the board and tighten the hex at the top to set it to the right height](images/251015-CNC-Mill-Toolpath.jpg) | |:---------:|:---------:| | *Setting up the trace cut file in mods* | *Inspecting the toolpath* | | ![I had to turn the machine on and off by pressing this button a few times because if I opened the door when it is running a command, it will have a blinking light and not want to continue.](images/251015-CNC-Mill-PCB-1.jpg) | ![You press the bit gently down into the board and tighten the hex at the top to set it to the right height](images/251015-CNC-Mill-PCB-3.jpg) | ![You press the bit gently down into the board and tighten the hex at the top to set it to the right height](images/251015-CNC-Mill-PCB-2.jpg) | |:---------:|:---------:|:---------:| | *Turn the machine on and off by pressing this button if the door is opened when running a command, It will have a blinking light and not want to continue.* | *Press the bit gently down into the board and tighten the hex at the top to set it to the right height* | *This is what the bit should look like to start milling* | | ![Starting to cut the copper traces. This seemed to be the right amount of "chipping" residue according to Gert and means things are running smoothly.](images/251015-CNC-Mill-PCB-4.jpg) | ![Starting to cut the copper traces. This seemed to be the right amount of "chipping" residue according to Gert and means things are running smoothly.](images/251015-CNC-Mill-PCB-6.jpg) | |:---------:|:---------:| | *Right amount of "chipping" residue means things are running smoothly.* | *The completed board with the holes and outline cut.* | I found that the board did not need any scraping or finishing, but did that there was a bit of copper that needed to be removed between traces at the top right. | ![The milled board right out of the machine](images/251015-CNC-Mill-PCB-7.jpg) | |:---------:| | *The milled board right out of the machine* | | ![The board with all the components](images/251028-Sound-Controller-Stuffing-Board-Process-1.jpg) | |:---------:| | *The board with all the components* | The components I used include: - two 10k resistors - Seeed Xiao Breakout Board with RP2040 processor - [B09JWN8K99 0.96 Inch OLED Module 12864](https://www.amazon.com/Self-Luminous-Display-Compatible-Arduino-Raspberry/dp/B09JWN8K99/?th=1) - two breakout pin connectors, of 4 pins each
Here is the process of soldering it: | ![Tinning the contacts for the resistors, best to do just one side](images/251028-Acoustic-Stuffing-Board-Process-2.jpg) | ![Placing the resistor down with tweezers and soldering one side](images/251028-Acoustic-Stuffing-Board-Process-4.jpg) | ![Soldering the other side](images/251028-Acoustic-Stuffing-Board-Process-5.jpg) | |:---------:|:---------:|:---------:| | *Tinning the contacts for the resistors, best to do just one side* | *Placing the resistor down with tweezers and soldering one side* | *Soldering the other side* | | ![Placing the XIAO down with just one pin](images/251028-Acoustic-Stuffing-Board-Process-7.jpg) | ![Soldering all the other pins](images/251028-Acoustic-Stuffing-Board-Process-9.jpg) | ![Adding the two physical breakout pins](images/251028-Acoustic-Stuffing-Board-Process-10.jpg) | |:---------:|:---------:|:---------:| | *Placing the XIAO down with just one pin* | *Soldering all the other pins* | *Adding the two physical breakout pins* | | ![Adding a piece of cardstock to protect the screen from short circuits](images/251028-Acoustic-Stuffing-Board-Process-11.jpg) | ![Placing the screen down on the pins](images/251028-Acoustic-Stuffing-Board-Process-12.jpg) | ![Soldering the screen](images/251028-Acoustic-Stuffing-Board-Process-13.jpg) | |:---------:|:---------:|:---------:| | *Adding a piece of cardstock to protect the screen from short circuits* | *Placing the screen down on the pins* | *Soldering the screen* | | ![Adding a piece of cardstock to protect the screen from short circuits](images/251028-Acoustic-Stuffing-Board-Process-14.jpg) | ![Placing the screen down on the pins](images/251028-Acoustic-Stuffing-Board-Process-15.jpg) | |:---------:|:---------:| | *Snipping off the back of the pins with clippers* | *Filing down the back of the pins with a file* | | ![The completed working board](images/251028-Sound-Controller-Stuffed-Smiley.jpg) | |:---------:| | *The completed board is up and running* |
> Extra credit: make it with another process [link-title](https://fab.cba.mit.edu/classes/863.25/) ## Attachments [attachment-1.ext](files/attachment-1.ext) ## Acknowledgments