Sunday, April 20, 2014

LCD Display with Dormant Labs PH Module V2

This is a stepping stone tutorial, and comes after first learning to measure PH, you should review this tutorial first.

For my own purposes I do want the arduino to show ph on a screen, without it being connected to a computer. This is the way I went about it.

The LCD I got is a "I2C 0.96" OLED display (for Arduino /PIC /AVR ) Blue/Yellow color" from the ebay seller ""

So I soldered some 2.54mm pitch pin headers to the lcd, then super glued it to the back of the ph module.

I then connected and soldered the SDA, SCL, VCC, GND pins of the lcd to the SDA, SCL, VCC, and GND pads on the ph module. 

I should note that I only used dupont cables because I had already soldered headers. If I was going to do it again I would just solder wires to both ends. Also, the area I applied the superglue to was the inductor.

So connect the SDA,SCL,VCC,GND pins of the ph module to your Arduino. After that, load up this code through the arduino IDE:

Follow the same calibration instructions as in the previous tutorial and now your arduino will display the ph on a screen.


  1. Put the lcd with the ph shield today, followed all the instructions, and the lcd is not lighting up. When I run the sketch on this tutorial in serial monitor, nothing happens. When I run the sketch configured without the lcd through serial monitor, I get all my data. Did i miss something in the sketch or have I a dead lcd? Ive connected the lcd the the jp3 line

    1. Not if you copied and pasted and then did the wiring correctly, its possible but I doubt it. Which arduino are you running it on? There is a possibility if it is one of the arduinos with lower ram then you are running out of memory. Did you buy the lcd from the same seller as me?

  2. Hi, I'm going to make your pH controller. In this post you says that you have bought the 'Blue/Yellow color' but from the pictures ( pic 1 and 2, the text 'bi color' is strikethrough that means that is the white model ) and I see that the lcd is the "Ultra white color" ( as the ebay page ) in the last picture.
    So, the question is, which one I need to buy? Ultra white or bi-color (blue/yellow)?

    Thanks a lot, I'm looking forward for your answer.
    Best regards, Marco.

    1. Hello Marco,

      Oh my, I just noticed after you pointed it out. I would still order the Blue/Yellow color.


    2. :)
      So? Which one I need to order now? Both are fine, or it's a good idea to order the ultra white to avoid problems?

      Thanks a lot again.
      Best regards,

      ps: When we can buy the new pH module (v3?) ?

    3. Hello,

      I would order this one:

      They should both be fine though. I say to order that one because that is the link I used to order.

      V3 will be out in 2016 or 2017.