pH and ORP stamp are using standard serial communication to send data they read from the probe. So I used the SoftwareSerial library to get data processed by the arduino and I connected :
- pH RX & TX pin respectively to pin 2 & 3 on the arduino
- ORP TX & TX pin respectively to pin 5 & 6 on the arduino
Temperature sensor is an analog sensor which I connected to pin A0.
Also, I connected power (3.3V) and ground to respective power lines of sensors.
Test code (which is way more complicated than it should be because I was first planning to use an arduino as the final solution… but then decided to go for a BeagleBone) can be found here : https://github.com/jsiobj/poolDuino
My fisrt pool monitoring system was Arduino based (more info here.) It could collect pH, ORP and temperature from my pool and store it on an SD card. But I wanted to send all this data to some web site like my own emoncms.
So I needed Internet access. To do this with an Arduino, I either need
- If I want Wifi, I found RN-XV module difficult to use and quite instable (no sure though if it is my program, the libs I use or the wifly itself.)
- A Raspberry Pi is less than 40€, has build in ethernet, is way more powerfull… and adding Wifi is ~20€
Problem though : Pi has only 1 UART available… and I needed 2. I known there are workarounds but having a look around, I stumbled upon BeagleBone Black (BBB) :
- Build in ethernet
- Many GPIO ports and several UARTs
- Running Linux
And “only” 45€ !
So I decided I’ll give it a try : poolDuino is now becoming bbPool !