ECUs Emergency

The Emergency Break Board gives a chance to remote stop the car. It is mostly independent from the other parts. Also its electric circuit is not connected to the main power supply system, so it will still work, when the other systems don't work any more. The Emergency Signal is given by an extra radio transmitter, sending on a frequency other then the main control unit.

Usage

Pushing any of the 3 Buttons on the emergency remote control sets the car in a stop mode. Changes on the main remote control do not affect the cars state. Only if all 3 Buttons are pushed on the emergency remote control, the car will leave the stop mode and reset to running mode. At

How the Emergency Board works

The Emergency Board sits between the acceleration and the steering control boards, and the active parts (motor and steering). If an emergency signal arrives, the signals that come from the control boards are being replaced with stop signals generated from the emergency board itself. The replacement is done by simply switching a multiplexer.

The signal transmitting part works with a SHR7 decoder board and a fully assembled transmitter unit. The decoder board receives the signal from the transmitter and generates a code that contains information on the sending device and on which buttons on the 3-button-control were pushed.

Software Component

The main task of the software running on the Atmega88 is to decode the signals from the shr7 decoder and decide whether to switch the running/stop state.