Read PH device LCD

Projects General Guidance
1

Ho there,
Basic question upfront is, how do I read/log data that is on an LCD display of other electronic devices.

I want to monitor my water supply as we are on a well and I would like to better calibrate our filtration system. I want to start easy with pH(acidity) and TDS(total dissolved solids) measured by PPM(parts per million). Both generally work by measuring electric current though the water and results are based on resistance. All I could find researching was people building their own device using arduino as the brain. These seem to work but leave some serious room for error and as long as I have lab grade equipment it would make life a lot less stressful to use it. I can only take so many readings a day and would like an automatic data logger to read the meters while I'm away. All this equipment has LCD readouts of the info I want so it seems like it would be an easy solution to passively read the final data instead of interpreting the raw output of the probes. Maybe?
Any help is appreciated, thanks,
Argus

2

welcome to the forum,

We do need some more info on what you want and what you have already.
What kind of monitoring do you want to do?

3

Lok at this thread: Digital scale hack Output LCD display to a file - Project Guidance - Arduino Forum

// Per.

4

Thanks for the replies,
My unit that I'm working off of is here:
http://www.testequipmentdepot.com/milwaukee/conductivity/mw801.htm

I am still in the research phase but I am confident I can get arduino to operate the unit and how to store data on an SD card but I'm at a loss for how to receive/interpret the output data of the unit

I see why the LCD readout is more complicated than it seems thanks Zapro

5

The unit with lcd seems to have no way to connect to another device for logging. There is also no information on the sensor, such as how to operate it and pin out. You may have to use their sensors without the readout unit. Google their sensors and see if you can find something useful.

6

Wish I had found this earlier but, for roughly the cost of the unit I have, I can get the sensor pens with analog arduino interfaces at www.dfrobot.com. I think it's worth the money to save countless hours of decoding electronics I already have. Thanks again Zapro. Would have never found it without you.

7

You have more options, like:

They look more professional, well done, but they are more expensive too.

EDIT: You can take a look to this thread too.

8

Does anyone know what protocol the atlas sensors use? SDI-12?

9

liudr:
Does anyone know what protocol the atlas sensors use? SDI-12?

Two data protocols
• UART asynchronous serial connectivity
• (RX/TX voltage swing 0-VCC)
• I2C (default I2C address 0x63)
• Compatible with any microprocessor that supports UART,
or I2C protocol

You have sample code too:
https://atlas-scientific.com/_files/code/Arduino_pH_sample_code.pdf?
https://atlas-scientific.com/_files/code/ph-i2c.pdf?