Core reads wrong voltage [FIXED]

[peekay123]

Folks, just a reminder that a LOT of discussions regarding the STM32 analog inputs can be found here:

Odd analog readings [SOLVED]

So I happen to have a TMP36 and decided to implement the temperature reading example. I connected it exactly as shown in the documentation, but I’m getting inaccurate readings. Whether I use a function, a variable or Serial.print I get values around 946. Using the method to convert this to voltage: $voltage = ($reading * 3.3) / 4095; I get 0.762 V. Convert that to Celsius using: $c = ($voltage - 0.5) * 100; And you get 26.2C (79.16F). however, the expected temperature is around 69F. If I ta…

Odd analog readings (part 2)

I did a bunch of testing today with my TMP36 temperature sensor to try and get to the bottom of why the readings are so wacky. This is a continuation of the Odd analog readings thread, but I felt you might want to find this information without reading 55 replies How to get accurate analog readings: Hook your analog sensor to the 3V3* pin and GND. The 3V3* pin has a low pass filter on it and is the same node that is connected to the Analog to Digital convertor’s re…