Week 0 - Fab Preparation

Before I began Fab Academy, I participated in workshops run by Mr. Dubick. Initally we began by going over soldering, both surface mount and through hole

Soldering an ATTINY 412 chip

Surface mount soldering and programming a ATTINY 412 Chip To start the first week of Fab training off we began by receiving the majority of our tools. After we received our tools, we reviewed how to surface mount solder, a skill I learned how to do over the summer. The method I found myself proficiently using was to place some solder onto the pad, move the component on top of the soldered pad, heat the solder again, and then you can solder the remaining pins you need to solder because it is held in place by the first joint. I did this on a practice board until I felt confident in my ability to solder my surface mount project, a blown up 555 chip. The 555 chip took a while, but after soldering and testing it, it worked!

Programming the 412 chip

After the chip was soldered, we tried to program it using an arduino. I referenced the datasheet for a 412 chip from William Zhou’s embedded programming unit in fab academy. I Linked pin 6 on the 412 chip to pin 6 on the arduino, pin one on the 412 to 5 volts on the arduino, and pin 8 on the 412 to ground on the arduino. I followed my workflow of how to use jtag to program a 412 chip, but here I ran into some issues. When doing all of the jtag uploading, all ports, programmers, and boards have to be correct in order for the upload to be correct. It took a while to understand this, and have everything correct, but eventually it worked. I uploaded the blink example from arduino IDE, and then I used a breadboard to wire all the components together. In this instance I needed to change the example’s LED pin to pin 2, as pin 4 on the 412 corresponds to pin 2 on the arduino.

Milling my first board

After we programmed the 412 chips, we milled boards using a desktop milling machine. There were numerous issues I encountered during this step. The first issue was the workflow we were provided with by Mr. Dubick was slightly out of order, as you needed to have a bit in the machine in order to probe the material thickness. I made a fatal mistake right away, after I placed the bit into the machine, I tried to probe the thickness of the board. I followed the instructions on the workflow, but missed a crucial step, making sure the board was electronically connected. I forgot to move the tab over the board, so the bit pressed deep into the copper board. I tried to move the spindle then, but only ended up scratching the copper and breaking the bit. I learned just how fragile the bits are after this, and now realize just how careful I have to be in order to keep the bits in working order. I then made another error. After my machine refused to work, I changed to the machine next to me, and did everything on the workflow correct to a certain point. I had accidentally made the trace depth 2 mm deep instead of 0.2 mm deep. When I cut the board this resulted in torn traces, due to the cuts not being clean. I learned here that it is very important to double check everything that you do or else there could be some severe consequences. I then got a premilled board, as I had learned from my mistakes that I made. I soldered the board, and then uploaded the same program used previously to make the LED blink when using a 412 chip. I then struggled to figure out why I couldn’t upload my code, where I then realized that the power and ground terminals on the board were switched from what was conventional. After I switched the wires, the chip worked.