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adafruit / Adafruit_ADS1X15

Driver for TI's ADS1015: 12-bit Differential or Single-Ended ADC with PGA and Comparator
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ads1115 all inputs tied together different readings #50

Closed jorythompson closed 4 years ago

jorythompson commented 4 years ago

I am reading all four inputs (non-differential) on an ADS1115 with a raspberry pi.
For grins, I tied all inputs together and then to ~3V (I am using a voltage divider to read 9V). I was surprised to see that all values are slightly different (as much as 11):

22045 22043 22051 22040

Is this reasonable? The wires are all in a breadboard and I have reseated them several times.

ladyada commented 4 years ago

yes ADCs have some offset, you can calibrate the offset in your code if neede