EC, pH and temperature voltage outputs to ESP32
Account cancelled 2026-07-15 20:00:23 164 Views2 Replies I'm looking to design hydroponic system monitoring using ESP32 controllers. Am I right in thinking that ESP32 using 3.3V input voltages for signals? And that the EC and pH sensors use 5V to power them from the ESP32? I can't find detailed information on the signal processing on the project kit chips (SKU: SEN0451 and SKU: SEN0169-V2), is there a conversion to 3.3V on that chip or is attenuation needed through the use of a resistor? Any pointers to any helpful documentation would be really helpful.
The SEN0451 wiki page has the signal board spec table (supply/output voltage) laid out clearly:
https://wiki.dfrobot.com/sen0451/
The SEN0169-V2 wiki/pro overview confirms the wide-voltage regulator and 3.3V/5V compatibility:
https://wiki.dfrobot.com/sen0161-v2/
For a worked ESP32 hydroponics build putting both of these together end-to-end, this blog post is a good reference:
https://www.dfrobot.com/blog-21377.html
If you'd rather sidestep this voltage-matching consideration entirely, the Arduino UNO and UNIHIKER K10 both run 5V-native analog inputs,
so the sensors' "classic" 5V calibration numbers apply directly without adjustment:
Arduino: https://www.dfrobot.com/product-2136.html
UNIHIKER K10: https://www.dfrobot.com/product-2904.html
Found that its actually 3V output for them so it all good
