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A project log for ReacTick

Snap-on Desktop Widgets

jarrettJarrett 10/16/2017 at 23:560 Comments

Prototyping aw yeah.

There's a bunch of work I did for that last log that I didn't post. How uncharacteristic of me. The following was written on November 6th, 2016 and posted elsewhere:

After R1, there were some things that I was planning on changing for the next respin. R1 just to get some hardware in my hands and start writing code. This next one is all about the cleanup.

The last version of this project works... Poorly. The code in the test folder is stuff to help me prototype, before I got to a working model. Originally, I tried writing an LCD driver in Python for the Raspberry Pi GPIO, but the output seemed super unreliable. Instead of taking the time to troubleshoot why, it was faster to port that code onto a PIC dev board, which worked great.

Once I had a known-good LCD (using the shift register), I finished soldering up the rest of the board and tried to bring up the whole board. It never quite worked properly, and here's why!

When I was first drawing my schematic, the most common ESP8266 module was the ESP-12. Right around that time, November of 2015, the ESP-12E had just come out, with a bunch of extra pins. No one knew much about this at the time, but the conventional wisdom suggested that it was safe to include them in my design, allowing me to get away without using an additional microcontroller. Turns out these extra pins are associated with the flash memory, and using them willy nilly causes strange reset issues. Guess what kept happening when I was trying to test my fully populated board?

So before a complete rethink was in the cards, here was the original plan for revision 2:

Some of these ended up making it in, but the new system design deprecated other points. So what's new in R2? Stay tuned to find out!

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