ESP32-S3-Mini and MCP3462R not working in Mux Mode

[LeKrakenTheCode]

Keep receiving a value of zero from analogRead. Moving this into its own issue from: #5 (comment)

[LeKrakenTheCode]

What's the speed of your SPI bus? I remember having some issues if the speed was over 500k. I'm currently running w/ 200k\

I was running at 10MHz. I lowered to 200KHz and still no change.

[Mirageofmage]

If you have access to a scope, can you check the activity on MISO?

[LeKrakenTheCode]

Sorry for the delay. Was feeling rather unwell this weekend. Working on it now.

[LeKrakenTheCode]

If you have access to a scope, can you check the activity on MISO?

I have this tool that can view SPI. Does this help? Please ignore the CS line, it is not connected as i didn't break out a header for that pin, however the analyzer is set to ignore the CS line for now.

[nerdyscout]

MISO and MOSI seem to show reasonable signals. Seems like the second picture is showing a 1Byte command followed by another 2Byte command... I did not try to figure out which are these. But it seems save to say MCP3x6x::read(Adcdata *data) is never executed as this would result in a 3-5Byte command. At least this is not shown in any of these pictures.

I still suspect the issue in this little snippet:

    settings.mux = ch;
    _status      = write(settings.mux);
    _status      = conversion();
    while (!_status.dr) {
      _status = read(&adcdata);
    }

please put an Serial.print(_status.dr) inside the loop and right in front of it, it looks like this is currently not executed. This bit should be set when conversion started and reset when valid data available. As this bit is part of the status byte endianness is important, but also timing of spi speed vs conversion speed might cause it.

[LeKrakenTheCode]

Here's the change and here is the output:

only one appears to be running.

[Mirageofmage]

Here's the change and here is the output: only one appears to be running.

I've had issues with the while loop, in my implementation I just directly read instead of waiting for the data ready bit. I have to be careful with my sample rate or it returns the same value for each of the channels.

[LeKrakenTheCode]

No change to the output.

[Mirageofmage]

[LeKrakenTheCode]

still no change to the output:

Trying to read MCP_TEMP.