Tuesday, September 26, 2017


...are faster than me.

But at least they're not doing a million things at once. Or building pinball machines. :)

Since last I've had some issues with the MCP23S17's, and they didn't want to function properly. I think I got the hang of them now though. There were a couple of issues, for instance;

1) One of the MCP's relied on the Max32 to send an enable signal to it, but it seems the pin can't supply the necessary voltage and/or amperage needed to keep it enabled. I temporarily jumpered it to 3.3V and that solved that. I will probably solder this to the watchdog output instead, since that and the other two MCP's relying on it seem to function properly.

2) The switch matrix MCP displayed the status incorrectly on the DMD. I'm still using a temporary DMD "library" that lets me dot pixels for basic trouble shooting. I forgot to add the clear buffer function, so every draw could only add to the screen and not remove. This fooled me to think that the built in pullups malfunctioned and/or the software for it. I've verified functionality with a LED instead and everything works as intended, and has most likely always done so.

3) I've moved away from all fancy MCP-libraries and communicate directly via SPI, and that probably helped a lot in knowing exactly what's going on. Will encapsulate this into functions optimized for the "thread" handling I've planned for them.

Lastly, I've, err, confirmed that the fuses function properly.
While testing the inputs I did something very wrong (i.e voodoo connecting things) and blew the 5V fuse. It's rated at 3.25A so that's a pretty decent amount of current that was blocked instead of frying other components. 

But at least things are moving forward! :)

No comments:

Post a Comment