As it is not always practical to attach another switch to the brake lever for logging purposes, it is also possible to connect the eChook to the brake light on the car instead. This requires a potential divider to step down the voltage driving the brake light voltage to 5v. To design the potential divider, follow the same guide as for connecting the throttle, and simply connect the output to the brake input. Depending on the car the brake light could be switched on the +ve side (i.e. 24v side) or the ground side. Ensure that the connection to the eChook is made on the switched side of the light, as shown below for a 24V brake light system.