Hello E2E Experts,
Good day.
I am a coorporating professor with a small senior project team that is striving to utilize your 16-Bit precision DAC. We have this wired and are testing the SPI, but after many hours we are still not getting any data out of the part. They are using RP2040 Rasberry Pi as their MCU. We have checked all base level things (power, clocks, configuration signals, etc). They have also checked the RP2040 SPI by talking to an arduino board to confirm reading and writing are working. I wanted to reach out for them to see if you have any simple things that might help get this working quickly.
First, it would be great if there were some support library or some sample code on how to build the SPI interface. In particular, it looks like the default SPI_TIMEOUT is 100ms, which may mean we are simply watchdogging the part as I believe they are currently trying to do a read every 2 seconds in their test code. Can you help with this?
Secondly, we have tested two different parts and the behavior is consistent (and odd). When we write our SPI transaction and expect to get a read back, the DOUT signal appears to start driving high, but basically stops at 0.3mV. I'm having the students to try and see if they somehow have the MISO pin set to drive low (which could explain this), but the SPI library they are using would be pretty broken if it did. I'm wondering if there is anything in the configuration of the board that could have the DOUT shorted to something else? We should not need any pullup on a SPI signal.
Regards,
CSC