Hey-yo! I have a hardware question about the Swan and I couldn’t find an answer on the datasheet.
Q: Is the Swan 5v tolerant on ADC inputs?
The STM32 datasheet says that inputs can be 5v tolerant and gives a formula for determining max voltage, but I’m not sure what features are getting used on the board to know what values to plug in. When I make a guess at what features are getting used, it seems like I could do up to 5.22v on the inputs.
I’m wanting to do some gas sensing with a few of the MQ-family of sensors. I have a bunch on hand and would like to use what I’ve got vs. buying something new*.
The MQs use 5v to power the heater and runs that through internal resistor. In practice, it’s probably quite a bit lower then 5v. I just don’t want to burn out a pin, or worse, the entire MCU. I’d also like to avoid doing a bunch of dividers to save prototyping space. I’m planning on using 4 of the sensors and comparing them for various gasses. I’m also not sure about the impedances, so I’m not 100% sure a voltage divider will even work well.
Anyway, before I get more off into the weeds I figured I’d just ask.