# Adafruit ads1115 for low signal voltages

**URL:** <https://forums.pimoroni.com/t/adafruit-ads1115-for-low-signal-voltages/681>\
**Category:** Support\
**Created:** [May 14, 2015, 10:10am UTC](https://forums.pimoroni.com/t/adafruit-ads1115-for-low-signal-voltages/681 "2015-05-14T10:10:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![smithy](https://avatars.discourse-cdn.com/v4/letter/s/a4c791/32.png) [@smithy](https://forums.pimoroni.com/u/smithy)\
**Post date:** [May 14, 2015, 10:10am UTC](https://forums.pimoroni.com/t/adafruit-ads1115-for-low-signal-voltages/681/1 "2015-05-14T10:10:36Z")

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Hi, I’m looking to add an ADC to my Pi but I need one that will measure down to 30mV.  
Can anyone help me work out if the ADS1115 will do that please?  
[My project is to measure the voltage dropped across a power mosfet so that I can monitor power used in a Greenpower car].

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**Author:** ![P1nky](https://avatars.discourse-cdn.com/v4/letter/p/8491ac/32.png) [@P1nky](https://forums.pimoroni.com/u/P1nky)\
**Post date:** [May 14, 2015, 11:21am UTC](https://forums.pimoroni.com/t/adafruit-ads1115-for-low-signal-voltages/681/2 "2015-05-14T11:21:46Z")

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It should work. I am currently finalising a design for a gas analyser, and the breadboard model can deal with the output of the O2 cell. That has a maximum output of ~70mV.  
One thing I would suggest is that your code ramps up the gain on the ADC, as using too high a gain (should you get a higher than expected input) will damage the chip. Overall, I would definitely recommend the ADS1115, and if you don’t need the resolution, the 1015 is just as good.