As I see it, you have 5 main choices…
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Use Bluetooth and live with the drawbacks of very low range and poor re-connectivity, in the same way that the DEFA product has.
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Use WiFi, which has greater range and better connectivity than Bluetooth, but which needs a known SSID to connect to.
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Use a mobile Blynk server, using something like a Pi Zero to give you a mobile WiFi hotspot/server. You still have limited range, but the only connection issue is between your phone and your hotspot. The Pi will add to the battery drain though (the ESP32 will have some battery drain of course).
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A combination of (1) and (2) which is more complex from a coding perspective and which still doesn’t really solve the underlying issues regarding Bluetooth.
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Use GPRS connectivity to enable your car to be connected to the Internet and accessible from any internet connected device at all times. There are some good IOT data only SIM packages which make GPRS connectivity good value for money.
The choice is yours, but one thing is certain and that is you won’t find an ‘out of the box’ solution that needs zero coding unless you buy a commercial package. If you do that then I’d suggest you buy something that gets better reviews than the DEFA system.
Pete.
Thank you Pete, so what you suggest as best solution for me? I dont like coding and want this relay and temp just work as plug and play!
I also want a nice app that can work with this setup! DEFA app has a very nice GUI:t but a simple On/Off button with a temp Measure and timer will suite me as well! I dont know were to find the gprs function or lets say I wanna use 2 esp32 server and a client!
The ESP32 isn’t powerful enough to act as a local Blynk server.
The TTGO-CALL is an ESP32 with built-in SIM800 GPRS modem. There are a number of examples of projects made with this board. If I were building a project like the one you’ve described then this is the board I’d use.
As I said, that’s not going to happen. You’ll need to do quite a bit of coding, and quite a bit of wiring within your car. There will be a trial and error process to ensure that your software and hardware work correctly with your car, and multiple relays will probably be needed to energise the ignition circuit and momentarily engage the starter circuit. Obtaining feedback that the engine has started is probably a good idea, and interfacing with the car’s heater controls may also be necessary.
Pete.
I have everything setup in car already, I just need to use One relay and communication from Iphone to the esp32 board to switch onoff the relay!