charge controller electric storage heaters

Projects General Guidance
1

I have a heating system with electric storage heaters. The storage heaters are charged during the night with cheep electricity.
The charge controller itself is already old and has a mechanical clock and I 'm afraid he will be end of life one of those days.
For that reason I will start a project with a arduino to replace the controller.

What is the charge controller doing :

  1. measuring the outside temperature every 30 minutes and calculating the average temperature of the last 24 hours.
  2. calculating the necessary charge for the next day (depending of the average day temperature of the last 24 hours)
  3. Calculating the charge time.
  4. calculating the starttime of the charging so that the storage heaters has accumulate enough heat when the night electricity go off.

Hardware I want to use :
arduino uno
arduino hardware clock
NTC
some output relais

The night electricity comes on around 11pm and stays on for 7 hours every night.

Is it possible to do this project with a arduino.
For me it should be a big challenge because I have not much experience in programming with arduino. Hope I will find here on the forum some help.

2

I would consider this problem quite doable. You seem to have a handle on the hardware. Start by hooking up one component at a time and getting it working. After that you can start to integrate everything together into the final product.

This might be feature creep, but you could theoretically add an interface to the internet and find a feed that will give you tomorrow's predicted temperatures. This would let you prepare for the next day instead of assuming tomorrow will be the same as today.

3

Note that this problem will involve switching mains voltages from the Arduino. That can be dangerous unless the hardware is designed correctly so I recommend that you look for a commercial switch that you can simply wire in. There are various mains switches around (some of them not cheap) and whatever you use will need to have a sufficient current rating for your heaters.

4

the hardware is not a problem. I know how to connect the in- and output on a save way.
The challenge is writing the software for the arduino

5

Well, steps 2 and 3 require you to provide some information and only you can do that. The rest of it seems straight forward enough, given that you can sort the hardware out.