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Core Electronics Forum

Analogue inputs Raspberry PI

#1

I am looking at using a 0.5-4.5V sensor into the Raspberry PI. It looks like there are a few options, I am looking at the below. I only want to bring in one sensor. I just want the simplest solution really and the solution with the most support (IE existing code). I think 10-Bit resolution will be enough for what I need, so besides the Bit resolution what should I go for? Also, any example wiring schematics would be amazing too.

ADS1115 16-Bit ADC - 4 Channel with Programmable Gain Amplifier
ADS1015 12-Bit ADC - 4 Channel with Programmable Gain Amplifier
MCP3008 - 8-Channel 10-Bit ADC With SPI Interface

sensor I am going to use:

#2

More info that might help with desicion, I am planning to make a simple data logger, 1 sensor in and logging to a file. If its successful I want to duplicate it (wire the same and duplicate the SD card) to make another, would I2C be better for this with the addressing?

#3

I would recommend using this one: https://core-electronics.com.au/ads1015-12-bit-adc-4-channel-with-progrmmable-gain-amplifier.html

It’s simple, it will work with a RPi, and there is example code about how to use it. I can’t imagine you would need higher resolution, but is hard to say with that sensor.

This ADC uses I2C, which would make it easy to connect multiple to one device. You could connect up to four sensors to this one ADC though, and use the same RPi to save the data to one or two SD cards if you wanted.

I hope that helps you get started. Let me know if you have any further questions!

#4

I am having a lot of issues… Can’t get the librarys to install! Following this https://learn.adafruit.com/adafruit-4-channel-adc-breakouts/python-circuitpython

I think my errors are with the PIP

If I do PIP3 it says command not found. I have python3.2 installed and set as default.

If I do PIP comand it runs but just alwasy says the same thing.

pi@raspberrypi ~ $ sudo pip install adafruit-circuitpython-ads1x15
Downloading/unpacking adafruit-circuitpython-ads1x15
Cannot fetch index base URL http://pypi.python.org/simple/
Could not find any downloads that satisfy the requirement adafruit-circuitpython-ads1x15
No distributions at all found for adafruit-circuitpython-ads1x15
Storing complete log in /root/.pip/pip.log

This is an older raspberry, I think maybe raspberry pi1.

Am I better off getting rid of it and getting a new one or maybe an arduino instead? OR will this not fix my issue?

#5

Hi Tom,

You may be experiencing compatibility issues with the old board. If you decide to use an Arduino you would not need an ADC at all to read your sensors. Before giving up on your RPi, follow this guide to setting up your Pi before starting the process:

Be sure to run these before starting as well:

sudo apt-get update
sudo apt-get upgrade
sudo reboot