Good evening!
I am new to these forums, have been working with a raspberry pi for some time now and have recently added an arduino to my project.
I have whats called a 'sleepy pi'. Basically its an arduino ATMEGA328P which attaches to a raspberry pi to offer a sort of 'sleep' or low power mode for the Rpi.
I have setup the TMP36 sensor as per the tutorial on Adafruit at.. Using a Temp Sensor | TMP36 Temperature Sensor | Adafruit Learning System and am having issues.
Im not getting accurate readings. The value returned from analogRead is consistently much higher then it should be.
If i measure the voltage output from the center pin of the device I get .74ish volts. (which converts roughly to my current room temperature (+/- a couple degrees). So I know that the device is working properly.
Example analogread values are 303-317. I believe with the voltages I'm seeing on the center pin I should be seeing roughly half of this value on the analogread.
I'm using a 5V source for the sensor. I have tried using different Analog inputs, and have even tried applying the voltage to Aref and setting the reference to external (actual voltage going into the device is 4.8v). Neither have provided me with any significant change in results.
I do not expect this is a programming issue so I have not included any code.
Attached is a picture of the Sleepy Pi board. The 5V source I am using is the red bubble +5V from 'switched expansion power' I have tried pins A0 and A5.
Thanks for any help that you may offer.
Tim