Here is a quick setup guide to help you get started measuring ph using arduino.
You will need:
- An Arduino
- Dormant Labs PH Shield (You can get this here http://www.tindie.com/products/rezahussain/arduino-ph-shield-by-dormant-labs/)
- A ph probe, any ph probe with a bnc connector will work. Here are some I recommend if you do not have a ph probe, PHE-1304-U, PHE-1311, PHE-7357-10. I use the threaded PHE-7357-10 in my setup. I have used several ebay probes and they also work well.
- 7.0, 4.0 ph calibration fluid. Part numbers PHA-4 and PHA-7 from omega are good. You can also get PH 7.0 and 4.0 calibration fluid from your local pet store in the aquarium section.
- three small cups to hold the calibration fluid and water to rinse the probe
1. Take your arduino and insert the ph shield on top of it.
2. Connect your PH Probe to the shield.
3. Download the Arduino Dormant Labs PH Shield Sketch , open it in the arduino IDE, and then upload. If you do not have the Arduino IDE installed, go to the Arduino site. Make sure you are using arduino IDE 1.0 or higher.
4. After uploading, open the serial monitor. The button is in the top right hand side of the Arduino IDE. It should start showing scrolling text similar to below. Don't worry about the values yet, they will be correct once we calibrate the ph probe. Leave this serial monitor window open on your computer.
5. Pour the 7.0 calibration solution into one cup, the 4.0 calibration solution into a second cup, and tap water into the third.
6. Start by rinsing your ph probe in the tap water.
7. Now immerse the tip of the probe into your 7.0 calibration solution. Swirl it around for 10 seconds, then press the calibrate button on the ph shield.
8. Now re-rinse the probe in the water.
9. Now immerse the probe in the 4.0 calibration fluid, swirl around for 10 seconds, and then press the calibrate button.
10. Your ph shield is now calibrated! The serial monitor in the arduino ide now will show correct information. You can now alter the sketch however you like.