CQ Robot TDS Sensor

[CWill1776]

Has there been any success connecting the CQ Robot TDS sensor to the Deluxe sensor extension?  I've searched extensively other forums to see, but I couldn't find any info about it.

[Rob F]

Hi, sorry for the long delay. Oh wow $8 that's amazing, if you get it working you'll have to comment on it's accuracy. Do be prepared for it not to be that accurate though.

Unfortunately the Pi doesn't have any analog inputs so all the sensor ports only read LOW or HIGH. To connect that to a Pi you need to add a ADS1115 module like this.

https://www.cqrobot.com/index.php?route=...ption=true

On the product page they had a link to the wiki page, they show how to connect to an Arduino and a Pi with some sample code. I happened to check the price of that going on Amazon, which is double, I decided to read a few reviews, one said there was issues reading with the Pi, another said the output didn't make sense but I don't know. Here's the link for the wiki, halfway down it talks about the Pi.

http://www.cqrobot.wiki/index.php/TDS_(T...QRSENTDS01

I noticed the Arduino pics shows the output in ppm as expected but in the last image on the page for the Pi the output is in millivolts. If that needs to be converted to ppm not sure how you would deal with that.

There's also a good chance you'll need an I2C isolator, without one it might not be that stable and interfere with the pH probe. CQ Robot doesn't have one but DFRobot does. Might be worth trying without one though.

https://www.dfrobot.com/product-1778.html

So yeah if you can get to the point where you get output in the Pi SSH terminal like the last image in the wiki we can work on a small mod so the value is saved to a text file on the Pi that reef-pi can then import and be available for alerts, control etc.

[gmax111]

This project may be of help for multiple additional sensors. PH, EC, TDS and ORP!

https://github.com/AnyLeaf/

https://www.tindie.com/products/anyleaf/...ll-probes/

[Rob F]

Thanks, I've seen those and they are probably fine however no stock. Also they would require running a 2nd script on the Pi like Atlas circuits to read them.