eBraking System

The eBrake System were designed to handle two scenarios. The first scenario is when both the throttle and brake are both active. In this scenario we want to signal the motor to be cut off. The second scenario is when the rider is braking and is pressing the brakes off and on, we don't want the motor to keep shutting on and off abruptly.

eBrake Circuits

The eBrake sensors use the same sensors designed by me on the previous page for the speedometer.

eBrake Placement

We planned to have the magnet in a case attached to the brake line, while the PCB sits in a case attached to the bike frame. When the brake is used, the brake line will move and the magnet along with it, passing the sensor and triggering it. Below is a picture of the idea. In the second picture is the idea of the 3d magnet casing. There will be another side to the case that snaps close between the brake line. It looks very thick here, but it will be much thinner in the final design, we just didn't get to measure an appropriate size at the time.

Handling Scenario #1

Scenario 1 is straight forward. When the brake send an active low signal and the throttle is high, the Pi will read the signals and then respond appropriately by sending a signal to open a switch between the power supply and the motor, which will cause it to disconnect.

Handling Scenario 2

In the scenario of pressing the brakes on and off, we needed to figure out how long should we keep the motor disconnected from the power. Below in the table is some measurements we did, recording the average time between hitting the brakes.

From these measurements, the largest time we got was 1.69s and the smallest was .7s, with an average of 1.3s. So we decided to wait 2 seconds before re-enabling the motor AFTER the last brake release.