I started this project out of poverty. When I just started the development of my enhanced autonomous biological system I got the question how I would know the status of the water quality without opening the system. It seemed a good question, a closed system is only closed until it is opened for the first time. After reading some publications on water quality I decided that pH would be the way to go especially when you are on a budget.  So I bought 8 pH monitoring systems and started to mount them in my Systems.

My first setup consisted of 8 stand alone pH monitoring systems. It was a nice setup to start with but there was one big disadvantage, I had to do al registration manually. So every day for moths I had to write down al values in my log. This wasn't a workable situation but it got me started and I got known with al testing methods. It also taught me things I didn't realize before I started and I learned a lot while viewing the progress of my systems. At the end of the first session I realized I needed to automate this process,... I needed a data logger. 

Soon it became clear that data loggers and data acquisition systems for 8 pH sensors with BNC connectors were to expensive. After searching for 2 months I found one at a dutch company, it had 8 analogue inputs not with BNC connectors but for stripped wire. So I contacted that company by email and asked them if I could connect 8 pH sensors to their system. Their answer was "Probably, you've got to figure that out yourself". This was the moment I made the decision that there was only one option left, I had to build it myself. Eventually I used my stand alone setup for 2 sessions before I got the the basics of my own data acquisition system running.

I started with an Arduino UNO and a temperature sensor and photoresistor. I had absolutely no experience with C++ coding but I did use R for Statistical Computing. However I had once bought a C/C++ coding book that I could use and I bought an Arduino starter kit to get my project started. It took me a week and in januari 2021 I had the data imported to R for Statistical Computing displaying the reading of the temperature and photoresistor in separate graphs on the screen of my laptop. This was my proof of concept, my idea of reading Arduino based sensor data with R for Statistical Computing and working with it in real-time was possible.

The next step was to connect 8 pH sensors to a laptop running R for statistical computing and displaying all the data on screen in graphs and logging it on the hard disk and an USB stick, you never know what will happend with an old hard disk. The next 2 years came a development phase of trail and error. I added parts and expanded, some parts broke or didn't work as expected and some sensor types interfered others.

Now years after I started this project I developed a multi functional sensor network for ecology, agriculture, space habitats and so much more. I can connect every environmental sensor for water and air, gasses and substances that is available for Arduino, connect it to R for Statistical Computing and process the data in real time. Nice for real-time monitoring, data streaming over the internet and even real-time modelling. The R based monitoring interface still needs some improvements but it is usable for monitoring the systems and all sensors.

The nice thing is that you don' need a expensive fast computer to run the monitoring and data logging software. In my lab I use it to monitor 10 sensors and it runs on a laptop with an Intel Celeron 1.7 Ghz processor and 2 Gb internal memory running on windows 8. So no need for expensive data loggers and dedicated monitors to view the sensor data. Just an old laptop running R for Statistical Computing. The next step in the development fase will be air monitoring and gasses with parameters such as; O2, CO2 and other hazardous gasses.