Motor Temperature and Speed on single input

Introduction

Some motors have motor or wheel speed and motor temperature on a single output. This page instructs you on how to set up this type of sensor input with your BAC controller.

This features works as follows:

1. Speed is calculated when the sensor voltage pulses below the threshold value.
2. The motor temperature is calculated using the input voltage, excluding pulses below this threshold. 

Wiring

The Motor temperature and speed sensor on a single input works using the Brake2 input (any of the Analog Inputs as of firmware 6.023).

Note

Firmware versions 6.022 and below only allow for this feature to work using Brake2/Analog Input 3.

Configuration

6.023+6.022 and below

1. Setup according to Speed Sensor Setup.
2. Setup according to Motor Temperature Sensor
3. Enable Motor Features bit 4 Single input motor temperature and speed pulses
4. Set the voltage threshold for single speed + temperature source.
   1. This value should be the voltage below which the temperature of your motor should not be. For example, if your voltage linearly decreases as temperature increases and your 100degC temperature is 0.5V and your motor should not go above 100degC. You could set your threshold as 0.5V or lower.
   2. Account for some float on the voltage when the speed sensor is active. Thus, a deadband, for example 0.2V, may be required and your threshold should not be lower than this or risk false readings from missed pulses.

5. Set Temperature threshold for Cadence detection to configure a timeout value for continous operation when the motor is engages but is stationary and the sensor is in a "pulse active" position.

   Example

   When on a hill and the motor is providing minimum torque resulting in slow/no movement, the speed sensor could be pulled down for an extended period. This timeout would cut the power output to the motor in order to protect it from overheating.

1. Setup according to Speed Sensor Setup.
2. Setup according to Motor Temperature Sensor
3. Enable Motor Features bit 4 Single input motor temperature and speed pulses
4. Set the voltage threshold for single speed + temperature source.
   1. This value should be the voltage below which the temperature of your motor should not be. For example, if your voltage linearly decreases as temperature increases and your 100degC temperature is 0.5V and your motor should not go above 100degC. You could set your threshold as 0.5V or lower.
   2. Account for some float on the voltage when the speed sensor is active. Thus, a deadband, for example 0.2V, may be required and your threshold should not be lower than this or risk false readings from missed pulses.

Limitations/Protections

When the motor temperature goes above 100 °C, the controller enables a flag. Once this flag is enabled, if the controller sees the input voltage below the threshold for a certain period, the controller sets the motor temperature to a very high value (500) disabling any power from controller to motor. As soon the voltage read on the input source is below the threshold, the controller temperature goes back to normal calculation.