Where can I find the timer + GSM to run webasto?

Question

Arduino

There is such a thing in cars, its name is Webasto - this is an engine preheater. Started and after 20-30 minutes a warm engine and interior.
The problem is that official control devices are unreasonably expensive:
- Regular timer - 3200r.
- Remote control with a button - 9950r.
- GSM control system - 13800 rub.
But in fact, webasto itself is quite smart, because. on board has all the control electronics. And to start it, + 12v goes out from these wonderful timers to the webasto control channel (consumption is less than 20mA). Those. we need to hang up on an incoming GSM call and apply 12v to the output for 30 minutes. At the same time, power is supplied from the on-board network of the car.
So far I see two solutions:
- Miracle thingwith a program in python (prog, I think I can write).
- Another miracle thing (inside the 220/12 converter, so there are no problems with power) and a timer for it on the NE555.
And then the problem overtakes me, that the system administrator, and not the circuit engineer ((Naturally I want the device the faster the better, because winter is coming. Hence the questions:
Where in St. Petersburg to get one, the other or analogues?
How to assemble a timer on 30 mins with 9-13v power on NE555
Perhaps you see other easier/cheaper solutions.

Answer 1

I myself didn’t deal with Webasto, but I repeatedly heard from car audio / signaling / heating installers that lovers of applying 12 volts to Webasto very often later regretted it - they say everything is not so simple there.
if I had such a problem, I would not be too lazy to look more closely (yes, even with an oscilloscope) how the interaction is arranged there