Tesla Bosch Radar

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Revision as of 19:49, 6 May 2019 by BogGyver (talk | contribs)

The Bosch radar made for Tesla (Bosch MRRevo14, and with few different part numbers like 1038224-00-A/B or 1057551-00-B) have been used on Tesla Model S cars from October 2014 (AP1) until they have been replaced by the Continental radar with AP2.5). The main difference between 1038224-00-B and 1038224-00-A is that the A version does not have the heater element for winter weather (to melt snow and ice).

The radar has a range of about 160m and for the short beam a cone of 45°.

Many other car manufacturers use the same radar hardware, including Honda, Nissan, VW, Audi, etc. But Tesla (AFAIK) is the only one that reads and processes raw data from the radar instead of letting the radar make the decision about longitudinal control action needed (acceleration or deceleration).

With a little help from a group of enthusiasts, we were able to reverse engineer all the messages that AP sends to the radar in order to make it "talk". Then we identified the structure of the CAN messages that describe each of the 32 objects this radar can detect. Signals like longitudinal distance, lateral distance (vs radar), longitudinal relative speed, lateral relative speed, longitudinal acceleration, certainty of detection, etc are all now processed and sent to the radar daemon of OpenPilot, improving longitudinal control for the car.

In order to get the radar working on your car, you need to buy a radar, a mounting bracket (few options here), a connector and then to create a harness and run the cable back to the firaffe. As a first temporary setup for my research, I used an Audi bracket which I installed on my car's nose cone. Then I created the harness and connected it for both CAN and power to my Giraffe rev B using a car relay. Please also make sure you add the 120Ω resistor between CAN+ and CAN-.

Giraffe rev B Radar Diagram.png

If you have a Giraffe rev A, you will have to solder the CAN wires from the radar directly to the radar. We are using the middle CAN of the Panda (CAN2 when you think of them as CAN1-CH, CAN3-EPAS) and the pins where you should solder your connector are marked in this diagrams.

Giraffe rev A.png
The Giraffe rev A board. Use CAN1 for radar..png

Also, you will have to add the same 120Ω resistor between CAN+ and CAN-.

As for power for the radar, if you don't feel like doing my relay setup from the giraffe, I recommend tapping into Pin 6 of the EPAS harness (which is "ignition" power) and drive a relay the same way i drove it from the Giraffe, but in this case add a 5 Amp fuse on the power from battery to the relay.