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Joined: Mon Feb 26, 2018 4:58 pm

Raspberry pi Pico voltmeter

Sat Jan 23, 2021 12:05 pm

I want to be able to measure the voltage of a 12v battery and display the voltage onto a 16x2 LCD screen. I was originally going to use an Arduino Nano, however with the new release of the Pi Pico with analogue inputs, I was wondering if I could use that instead. unfortunately, I have been unable to find the maximum input voltage on the Pico's analogue pins. So my question is, what is the maximum rated input voltage on the input analogue pins?


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Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

Re: Raspberry pi Pico voltmeter

Sat Jan 23, 2021 3:50 pm

Page 625 of the RP2040 datasheet -

ADC Input Voltage Range : 0V min, ADC_AVDD max

Page 626 -

ADC_AVDD : 1.62V min, 3.3V typ, 3.63V max

Page 174 -

ADC_AVDD supplies the chip’s Analogue to Digital Converter (ADC). It can be powered at a nominal voltage between 1.8V and 3.3V, but the performance of the ADC will be compromised at voltages below 2.97V. To reduce the number of external power supplies, ADC_AVDD can use from the same power source as the digital IO supply (IOVDD) - The voltage on the ADC analogue inputs must not exceed IOVDD

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Joined: Sun Jul 21, 2013 2:21 pm

Re: Raspberry pi Pico voltmeter

Tue Jan 26, 2021 3:13 am

Battery voltage monitoring will no doubt be a common application. I'm giving the pico a shot as well to measure my raw drone battery voltage and pipe it through the UART port. There's a nice github write up for the regular pi here for battery management:

But seems like using a voltage divider in the 10k range is the simplest approach. But yeah, standard range for ADC seems to be 0-3.3v. Just leave some room since a charging 12v lead acid can approach 15v.

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