poolDuino hardware & software details

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.

PoolDuino 640x480

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

From poolDuino to bbPool

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

  • An Arduino Uno + an ethernet shield (~20€ + 35€ = ~55€)
  • An Arduino Ethernet (~60€)
  • An Arduino Uno + Wireless Shield + RN-XV Wifly (~20€ + +17€ + 44€ = 81€ )
  • An Arduino Yùn (~62€)


  • 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 !