I thought I would outline my project so that if anyone thinks I am reinventing the wheel in places they can, please, advise me.
First the History:
Following an accident I am now disabled and partially sighted.
My wife and I had just bought a 16th Century Spanish Watermill needing total renovation, whilst I worked away in Switzerland.
Part of the project was to live off-grid utlisng Solar, Wind and eventually water to generate a normal 230Vac power supply.
After I blew up parts of my system by not knowing it was going wrong I have decided to create a web enabled sensor driven system, so even when I am in hospital I can check / receive warnings and be proactive not inactive.
I have decided to use an Arduino Mega as the Master / Web server and the controller for various odds and ends like flame and gas detection.
I will use an Arduino UNO as a slave to monitor each of the 2 banks of 12 x 2Vdc 1200Ah Lead Acid Batteries, for aggregated voltage and current, individual battery Voltage & Current, Temperature and State of Health (including Specific Gravity & Electrolyte Levels).
The system is 24Vdc feeding a Victron Inverter Charger.
I will use an Arduino UNO as a slave to monitor the 2 banks of 5 Solar panels & the 3.5K Watt Wind Turbine.
Lastly just because I want to I am using another Arduino UNO slave as a weather station.
All data is fed to the Arduino Mega for data logging and Web Serving.
I assumed measuring the SOH / SOC of the batteries via Specific Gravity would be easy as there would be thousands of Specific Gravity Sensors around.
Mistake number one: So I am attempting to make my own. I have now found that I can make probes out of Plumbers Solder as this is flux free and the only material the electrolyte will not degrade or contaminate the batteries.
So now I need 30 standard battery caps to fit the Hawker batteries so that I can attach the probes. As they are no longer used except on off-grid batteries this too is a challenge to find these.
Each cap will report, temperature and electrolyte level, plus I need to capture voltage and current.
Once a month the batteries are "boiled" by the Victron with system wide amps up to <100Adc so any sensor has to be hardy. Any suggestions on sensors greatfully received...
All will be housed in a purpose built box, which has 230Vdc fans and cooler plates embedded as temperatures in this part of Spain get high in the summer. Also the box will have a 2.8" Adafruit TFT Touch Screen controller on the front.
Currently I am extending the EEPROM library as each Arduino will carry details of who and what it is and does in EEPROM.
With such details as Master / Client ID, IP address, Gateway, MAC etc, where pertinent, which can be changed via web page.
I am also collating Arduino diagnostic routines to report the board type, RAM, SOH etc.
I am also trying to see if it is possible to store data on a standard 2.5" USB drive as backup, rather than just SD cards, it may be that I have to throw in my RaspberryPI as the data logger and or main controller.
I will post more on the project as I am going along, but please any advice gratefully received.