Originally Posted By: mlord
Yeah, I switched to 5K-ohm when actually wiring it up because there's a slight loss across the diode, and 5K-ohm worked so I never tried 10K-ohm.


Actually two 10k ohm resistors with the diode work fine.

I. Found. The. Problem.

Somehow the reset line worked fine when I first got the Betz board, but then at some point, it stopped working. I was measuring voltage on the RST pin on the edge of the board just fine when the Pin51 code triggered, so I imagined that must be fine. I tried doing different resistor networks to try and move the voltage up and down, no effect at all.

Well, one should always check one's assumptions. I was assuming the voltage from our Pin 51 code was reaching the WT32i chip.

NOPE.

Started tracing continuity on the Betz board. The line from the RST pin goes through a Via before connecting finally to one of the legs of the reset button on the Betz board. Somehow, the Via lost its connectivity and stopped transferring voltage through from one side of the board to the other. After tracking the lines to that Via, and scraping away the ink on the top and bottom, I found that there was no continuity through from one side of the board to the other. (And I triple and quadruple checked that it was the correct/same via on either side of the board of course.)

Made a jumper wire go from the RST pin to that leg of the reset button and BOOM the reset line works every time now, with our original design of (in my case) two 10k resistors and a diode.

Bam.

Now: On to that RX/TX serial port garbage issue. Not sure if fixing this will also fix that or not.

_________________________
Tony Fabris