Here’s the fully assembled board. I have the Pi sandwiched between the Base board and the Grove Pi. I like this setup, since it gives me more I/O and adds two more serial channels for me to use, even one straight from the Pi. I also might like to try my Logi-Pi Spartan 6 board this way with the PMOD ports, if I can figure out the FPGA side.
The Grove is just another I2C address to the Codesys. It has a simple little command protocol mechanism that I can talk to any of the Grove Modules via the on-board ATMega 328 mcu.
I intend to use the Grove I/O mainly for the Operator Interface that won’t exit the enclosure, and use the industrial 24V out on the external I/O. It could be a really good fit in my opinion.
I am seeing weird performance from the Grove Temp/Humidity sensors though. Seems like a bug in their firmware, since I get the same readings in Codesys as I do the Python test code.
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| Base Board with Grove Pi+ |
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| Base Board with Logi Pi |