Improved code for Arduino that creates the 433MHz ASK signal to open the Tesla Charge Port.
Arduino Code that recreates as good as I could get it the signal send out by an original Tesla UMC2 Adapter. Available codes on the internet did not work to well for me or did not work our for Arduino. So I sampled the transmission of a Tesla UMC2 adapter with a 433MHZ ASK receiver and a logic analyzer. There is a central part which is Manchester encoded but that it not all that is sent out. Todo: add more details here later. The code is written in a very simple form using delay() which makes the code very portable. This does not create the most precise timing tough it is fully sufficient for the Tesla signal.
Here is a snapshot of the sniffed signal for reference:
Connect a 433MHz ASK Transmitter to Pin 11. Pin 10 may be used to supply voltage to the 433MHz TX module (pls check power consumption). Code transmits the opening command with 10 repetions once after power up.
Hints:
- Pls note that the cheap FS1000A modules usually do not work. Use an STX882 or use one of the proposals on a net which rework a 433MHz remote to a programmable ASK transmitter.
- Using Optiboot as the bootloader for Arduino speeds up the startup tremendously. On the old bootloader (still often supplied) the Arduino takes approx 2 seconds to begin code execution. With Optiboot this is rather immediate. So wiring up the Arduino over a momentary toggle is enough.
- The 433MHz signal only works if the car is unlocked or recently has been locked. Tesla's logics is that you cannot open the charge port if the owner is not present.
- Tested on 328p and 168 Atmega so the most cheap thing does the trick.