Output Expander not driving data lines

I have an Output Expander connected to an ESP32 Wrover running the testChannels.ino that comes with the Arduino driver for the Output Expander.

The only change I made to the testChannels.ino was the pin number tied to Serial1.

I am getting output on the Serial1 output pin, and the yellow LED on the Output Expander is flashing like crazy.

But the 8 data lines for the WS2812 LED strips are all staying at 0 volts.

I have tried a couple things to see what might be the problem:

  1. I noticed the driver has some #ifdef ESP32, so I added #define ESP32 just in case it was needed, but it did not make a difference.

  2. I changed the baud rate from 2000000L to 1000000L. When run, the yellow light on the Output Expander no longer blinks. So I replaced it with 2000000L and the yellow light blinks again.

This leaves me with a couple questions:

  1. What does the yellow blinking light specifically mean?

  2. Any ideas on why the 8 data lines are not being driven?

If the orange LED on the expander is pulsing, it has power but is not seeing any valid expander data. A solid orange LED indicates that it is seeing some valid expander data. If the green LED is off, it is not getting LED data for it’s channels (check address), and once it gets some valid data for it’s channels and a draw command is being sent, the green LED will be on solid.

The baud rate must be 2M baud. It will not work with 1,000,000 baud.

Can you share the code you are using?

Silly me. I connected the two PCBs to a common ground and it is now working!

There is a solid Orange LED, but I do not see any other LEDs. The connected WS2812 strip is working and updating though.

My expander is V2.0 if that makes on difference on the LEDs.