hardware really is something else

i just picked up an old VFD project to show some data on it but I never got the serial transport code working... time to do some digging.

First, I setup a remote serial console with circuitpython going to the device and started sending messages.

Turns out the buffer (which i assumed was either larger or smaller) on this device is 2 characters. rather than waiting a lil and reading in more buffer data i just exited when the serial buffer was empty.

My first approach was almost right – but needed to send characters in sets of 2 instead.

Learnings:
1. probably want to use a different timer slot than this one to update data. We get a fun flash while serial characters are shifted over. Remember we're in the main loop? well, another fun thing with the main loop is that there is enough of a delay that you need to wait (0.07s) to send packets to read them.

Messages 8 long were getting totally garbled and messed up. Messed around the the baud initially thinking it was a timing issue.

The code read in serial via hardware and read it on each 300 semi tick of a system clock scaled off the 32.8mhz crystal.

I thought it was that the message wasn't being received all in one.