Hello EE's
I'm using the MCP39F521 on a project and have the ACM0686 Dev Kit hooked up to a Particle Argon, and I'm having many strange I2C issues, might be Partciel might be Microchip, and I'm still stuck. I'm able to get the same code working on an Arduino 34u4 feather, but when I connect it to particle, everything falls apart!
I've posted the issue in the Particle community
https://community.particle.io/t/mcp32f521-library-port-to-particle/56952/34 and after reading through your ideas and solution wanted to see if you see anything I should try to get my code working. I can get data from an LM75 temp sensor without issue on the same I2C bus, so know the i2C bus is working as expected fro smaller data packages.
I have a simple setup with the Devkit connected directly to the Argon/Boron Gen 3 Particle device. It uses a nRF52840 MCU and its own customer HAL layer to allow wiring like code, similar to Arduino.
Current Development Setup
Right now, I can get the Write setup as expected, know the hardware works with another MCU, and confirm that the read command starts off correctly but don't receive the expected 0x06 back from the MCP39f521 sensor. At this point, I read 0xC1, not the correct response header, and then either all zeros of ones fro 32 bytes of data.
If you look at my Particle community post, you can see logic captures and data back from the sensor and what the MCU is doing. Anouther strange thing is it won't work at 100MHz but seems to "Work" the i2C bus behaves and doesn't have missing ACK's.
I'm not sure what else to try besides messing with Particle's Hal layer, but that is slow and will defeat the entire purpose of using their platform. I'm going to take a scope capture tomorrow, but I don't think it has anything to do with capacitance on the wires because it does work with another MCU.
Any ideas would be lovely, and I'm not sure what else I can change or manipulate at this point to get data from the chip.
Best,
Nicholas