The schematic of the MicroMod Machine Learning Carrier Board shows the camera connector IOVDD connected to 1.8V, but the MicroMod I/O are all 3.3V. The Himax datasheet says the I/O should not exceed Vdd-io +0.3V.
How are these supposed to work together?
Am I missing something?
I am trying to use these with a custom MicroMod processor board.
Looking at the schematics of the machine learning carrier board is shows a 1.8V regulator
Looking the Himax datasheet I see that 1.8V is what is expected
I agree that the 1.8V it provides to the camera is within specification.
But the voltage levels on SDA, SCL, and MCLK from the MicroMod processor are 3.3V which exceeds the 1.8V + 0.3V rating of the camera I/O. The 1.8V signals coming from the camera also do not leave much margin for Vih to the processor.
While I think you are correct about the i/o levels, perhaps it isn’t enough to actually damage the camera module as I’ve used this combo successfully before without issue and we haven’t had prior complaints…
So while it might seem risky I believe it should be fine MicroMod Machine Learning Carrier Board Hookup Guide - SparkFun Learn
If you run into any issues after hooking it up/testing let me know and I can fix ya up 
Yes, we run the HM01B0 out of spec. It’s technically not rated for 3.3V at all (datasheet says 3.0V max), but it’s perfectly happy with 3.3V, so we run it out of spec for simplicity and lower cost. I’ve never personally experienced any issues.
I’ll give it a try, but I probably would have used a 2.5V or 2.8V regulator instead of 1.8V. That is within the range specified by HM01B0 and it provides a better Vih for the 3.3V I/O.
The camera’s I/O runs at 1.8 V, so the carrier board likely uses level shifters to interface with the MicroMod’s 3.3 V I/O. You’ll need similar level shifting on a custom board to safely connect them.
I’m using the Machine Learning carrier with a custom processor board. The processor board is designed with 3.3V signals to be compatible with the other MicroMod processor boards.
