Howto use a MQ-7 sensor 5v signal with 3.3v (Photon)

Hi, does anyone got a clue how to do a 5V analog input towards the Photon?

Also I wanna note that I have the bare sensor and not a breakout module :slight_smile:

Use a voltage divider to scale the signal from 0-5V to 0-3V

Yeah I was told that all until someone told me that the impedance would be off.

Apparantly the Photon has a STM32F205 that has quote from irc: “4pF sample & hold cap with 50k of series resistance” that would mean that at low samples they said you’d have problems.

I think I need to use an opamp for this to buffer.

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