Passed the test in the morning!

The 10k+10k voltage dividers on the I2S lines solved my cold start problems.


Current working setup of the Betz board is:

- JP4 cut after updating firmware.
- 470uF cap at C16 removed after updating firmware.
- IISC pad from Empeg goes to PCM_CLK on Betz+WT32i via a 10k/10k voltage divider.
- IISW pad from Empeg goes to PCM_SYNC on Betz+WT32i via a 10k/10k voltage divider.
- IISD1 pad from Empeg goes to PCM_IN on Betz+WT32i via a 10k/10k voltage divider.
- RX from controlling CPU goes to TX on Betz+WT32i.
- TX from controlling CPU goes to RX on Betz+WT32i via a 10k/10k voltage divider.
- 3.3v from controlling CPU goes to BATT on Betz+WT32i.
- 3.3v from controlling CPU goes to ENA on Betz+WT32i.
- 3.3v from controlling CPU goes to 3v3 aka VDD_IO on Betz+WT32i.
- 5v not connected on Betz board.
- Betz 2 pole slider switch set to the down/right/off position.

In my case I’m getting the 3.3v from the Arduino by powering it with 5v on Vin, and it’s workimg even though there should be 7v on the Arduino Vin.

Thanks so much for all the help and advice!

State of the project:

I have one minor software issue to iron out that I should have fixed by tonight some time.

Hardware wise, I’m ready to create a final PCB design which is based on the idea of piggybacking onto the Betz board. However that might not be feasible for reselling because I’m not sure Peter Betz can supply any more of these boards or not. I might need to create a board where I’m soldering the wt32i onto it myself.

Then I 3D print a nice enclosure and I’m done and ready to sell kits.