jmn98
Posts: 3
Joined: Thu Dec 13, 2018 2:44 am

ADC sample rate (ADS1115)

Thu Dec 13, 2018 2:52 am

Hi all,

I recently picked up an ADC, the adafruit ADS1115 module - https://www.adafruit.com/product/1085

I have tried installing a few different python libraries from github with mixed success. I have only been able to record data at 10-15 ms/sample but I want to be able to boost the sample rate to the max (860 sps). I've not yet been able to work out how to increase the sample rate.

For those with experience using these devices can anyone share with me what the best approach is, any examples or sample code? I've been chasing my tail and not getting anywhere.

Cheers,
Jack

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OutoftheBOTS
Posts: 711
Joined: Tue Aug 01, 2017 10:06 am

Re: ADC sample rate (ADS1115)

Thu Dec 13, 2018 11:49 am

I have use an ADS1115 ADC many times. it is a really nice ADC with programmable gain and high resolution ADC. The ADC it's self is very fast to make ADC conversions the problem will be is in the communication speed between the ADS1115 and the RPi as it uses I2C which is 1 of the slowest forms on communication.

You can look at increase the bus speed of the I2C see https://www.raspberrypi-spy.co.uk/2018/ ... bus-speed/

Also you can look at how the library your using is working and if it is doing a lot of unnecessary reading/writing to the bus. I tend to write my own simple driver to do what I need that way it isn't running slow because it is doing a heap of unnecessary stuff.

ysmnyol
Posts: 36
Joined: Thu Jan 24, 2019 9:19 pm

Re: ADC sample rate (ADS1115)

Tue Feb 26, 2019 12:34 pm

How can increase sample rate ADS1115 with this library?

https://github.com/adafruit/Adafruit_Ci ... ads1x15.py

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tlfong01
Posts: 1312
Joined: Sat Jun 02, 2018 1:43 pm
Location: Hong Kong

Re: ADC sample rate (ADS1115)

Sat Mar 02, 2019 5:04 am

OutoftheBOTS wrote:
Thu Dec 13, 2018 11:49 am
You can look at increase the bus speed of the I2C see https://www.raspberrypi-spy.co.uk/2018/ ... bus-speed/

Changing I2C Bus Speed Problem

It appears that Rpi Spy's instruction only works for old Rpi models. For 3B+, no one knows how to change I2C bus speed :(

RE: RASPBERRY PI3 I2C BAUD RATE SETTING Postby samtal » 2018-Aug-06 Mon 4:55 am
https://www.raspberrypi.org/forums/view ... d#p1349404
I am an electronics and smart home hobbyist.

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