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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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Library does not properly put ADS1115 to sleep in single-ended mode, uses full 300uA+ 24/7 #92

Open moeburn opened 2 months ago

moeburn commented 2 months ago

I am testing this with a multimeter. Comparing this sketch:

https://github.com/adafruit/Adafruit_ADS1X15/blob/master/examples/singleended/singleended.ino

...with this nearly identical sketch from a different ADS1115 library:

https://github.com/wollewald/ADS1115_WE/blob/master/examples/Single_Shot/Single_Shot.ino

The Adafruit library results in the multimeter showing ~320uA constantly. The other _WE library shows the multimeter reading 0.2uA most of the time, and then briefly jumping up a bit during each read before going back down to near-zero. This is how the ADS1115 is supposed to behave in single-ended mode.

I cannot confirm if this behaviour is the same on genuine Adafruit brand modules. I can only say that this library is no good if you are using 3rd-party ADS1115 modules, if you are expecting full power savings in single-ended mode.

caternuson commented 2 months ago

What ADS1115 hardware is being used for testing?

Is the only difference between the setups the Arduino library being used?

moeburn commented 1 month ago

I've tried this on all the various ADS1115 modules I have, on an ESP32C3. Correct, the only difference is changing libraries, and suddenly the current properly drops to 0 after a single ended reading.