I am trying to use the ADS7028 IC to use it's special feature in outputting a 16 bit RMS reading from one of it's eight input channels.
I created a circuit board for it and have it hooked up to an Adafruit ESP32 feather development board through it's SPI channel. After hours of debugging I still haven't been able to get any (meaningful) data from the SDO pin from the ADS7028.
Upon attaching a logic analyzer to the SPI channel, everything on the CS, SDI, and SCLK pins looks as it should be. However, oddly on the SDO pin as soon as I bring the CS pin low to initiate an SPI read or write, the SDO pin immediately starts showing activity, even before the SCLK starts moving. Nothing in my firmware would suggest I'm doing anything wrong with the SPI transfer. I'm really at a loss for what could be going on here.
I can attach board and schematic files, firmware, the output of the logic analyzer, or even just a picture of my setup if that would be helpful in figuring out what this issue might be with the SDO line.
As always thanks for your help!
Ben