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Features Configuration

Comprehensive guide to configuring ASI BAC controller features including assist levels, cruise control, reverse, walk mode, and display integration

Levy Fleets TeamJanuary 12, 202520 min read

Features Configuration

This guide covers the configuration of user-facing features for ASI BAC motor controllers, including assist levels, cruise control, reverse operation, walk mode, and display integration.

Assist Level Configuration

Assist levels allow the rider to adjust maximum power and speed. Depending on the type of displays or buttons used, these levels can be adjusted dynamically.

How Assist Levels Work

Assist levels set two key parameters:

  • Assist gain: Limits output current/power (0-100% of active motor output power limit)
  • Assist speed limit: Limits active speed in speed-limiting modes (0-100% of speed limit)

Assist Mode Sources

ValueSourceDescription
0NoneAssist speed limit and assist gain always = 100%
1AnalogUses voltage-based interpolation
2DisplayUses PWM values from display
5Network gainsRemote control via network
9DiscreteDigital input selection
11Momentary switchCycles through levels with button press

Analog Assist Configuration

For analog assist devices (JT405, potentiometers) with 0-5V range:

1

Connect Hardware

Connect the analog assist device to the Brake 2 input of the controller.

2

Set Assist Mode

Set Assist mode source to 1 (Analog).

3

Measure Voltages

Poll and read the Brake 2 voltage input to measure the analog assist levels.

4

Configure Low Voltage

Enter the level 0 (low assistance) voltage into Assist low voltage reading.

5

Configure High Voltage

Enter the level 3 (high assistance) voltage into Assist high voltage reading.

The controller linearly interpolates between Assist gain 1/Assist speed 1 at low voltage and 100% assist at high voltage.

Display Assist Configuration

For display-based assist control:

Display Interpolation

Displays typically send PWM values that may not match 1:1 with assist levels. The controller interpolates between configured gain/speed values based on the PWM signal.

  • Assist level 0: Assist gain and speed limit set to 0%
  • Assist levels 1-3: Map to Assist gain 1-3 and Assist speed 1-3
  • Higher levels (4-9): Interpolate between configured values

Momentary Switch Configuration

For single-button assist level cycling:

  1. Configure Momentary Assist Source to the digital input connected to the switch
  2. Set Momentary Assist Modes to total number of assist modes (including zero-assist)
  3. Configure Assist gain and Assist speed parameters for each mode

Mode Count

The Momentary Assist Modes parameter must include the 'zero-assist' mode. For 6 configurable gains/speeds, set this to 7.

Cruise Control

Cruise control allows users to operate at constant speed when in torque mode or torque with speed limiting mode.

Cruise Input Sources

BitSourceInput Type
0Hall CDigital
1Hall BDigital
2Hall ADigital
3PFSDigital
4CruiseDigital
5Brake1Analog (Active low)
6Brake2Analog (Active low)
7ABMSAnalog (Active high >2.7V)
8ThrottleAnalog (Active high >2.7V)
9Remote BrakeNetwork
10Remote Power SwitchNetwork
15Remote ReverseNetwork

Cruise Configuration

1

Select Input Source

Enable the appropriate bit in Cruise Enable Source for your input type.

2

Set Input Mode

Set Cruise Input Mode:

  • 0: Momentary push button (press to engage/disengage)
  • 1: Latching switch
3

Configure Minimum Speed

Set the minimum cruise speed (km/h) the vehicle must exceed to enable cruise.

4

Set Torque Limits

Configure Cruise Braking Torque Limit and Cruise Motoring Torque Limit as percentage of motoring current.

5

Configure Disengage Thresholds

Set Cruise Disengage Increase Threshold and Cruise Disengage Decrease Threshold for allowable speed deviation before cruise disengages.

6

Enable Feature

Enable Features5 bit 14 to activate cruise control.

Reverse Operation

Reverse allows the motor to operate in the opposite direction via a switch or network command.

Wiring

A single-throw switch is typically used, connected between GND and either:

  • Cruise/Digital Input 1
  • PFS/Digital Input 2 (Firmware 6.019+)

Legacy Firmware

For Firmware 6.018 and earlier, Cruise/Digital Input 1 is the only input option.

Reverse Configuration

1

Enable Reverse

Enable Features bit 1 (Reverse enable on cruise).

2

Select Input Source

Set Reverse Enable Source (address 1936) for Firmware 6.019+.

3

Set Speed Limit

If in a speed-limiting mode, set Vehicle jog speed to limit reverse speed.

4

Configure Interlock (Optional)

Enable Features bit 7 (Reverse interlock disable) to allow switching to reverse without coming to a full stop.

5

Verify Operation

Enable reverse and verify eBike flags bit 8 (Reverse) becomes active.

Network Reverse Control

For network control, send a command to Remote Digital Commands bit 15 (Enable reverse) - available in Firmware 6.019+.

Walk Mode

Walk mode is an auxiliary command source typically triggered via display or network for walking alongside the vehicle.

Walk Mode Setup

1

Enable Walk Mode

Enable Features bit 11 (Walk mode enable).

2

Set Signal Source

Set Walk mode signal source to 4 (Serial/display).

3

Set Speed Limit

Set Vehicle jog speed to limit walk mode speed.

Speed Limiting

Speed is only limited in Speed regulator mode 0 (Speed) or mode 2 (Torque with speed limiting). Mode 1 (Torque) is not speed limited.

4

Optional: Custom PI Gains

Set Speed regulator Ki for Walk mode and Speed regulator Kp for Walk mode to non-zero values for custom walk mode tuning.

5

Test Operation

Enable walk command from display, or write 1 to Display walk command via network.

EN Configuration Requirements

For TE Configuration 1 Pedal Bikes (ISO13849) "EN" firmware 6.017+:

  • Requires heartbeat faster than 0.4 Hz
  • Send Remote state command with rolling counter:
ByteFunctionNotes
Low byteRemote State Command0=Off, 1=Idle, 2=Active
High byteWatchdog CounterRolling 0-255 on 100ms interval

Display Integration

Displays provide user input for assist levels, diagnostics, and rider information.

Wiring Warnings

Voltage Warning

The B+ pin outputs battery voltage. Ensure the display is compatible with this voltage, or use the 12V output pin instead.

Wiring Caution

If wired incorrectly, battery voltage could damage communication ports or the control board. Verify pinout with your display manufacturer before connecting.

Supported Display Protocols

ValueProtocolInterfaceNotes
0DisabledN/A
1SWLCD open 9 modeTTL
2SWLCD (closed)TTL
4KM5 open 9 modeTTLKing Meter Open, 9 assist levels
5KM5 open 5 modeTTLKing Meter Open, 5 assist levels
6Wuxing 3 modeTTL
7Bafang displayTTLSpecific Bafang protocol
8KM5STTLKing Meter 5S protocol
9Big StoneTTL
10Bafang BMSTTL
11KTTTL
12Omni IoTTTL

Display Configuration

1

Connect Display

Wire display to controller, verifying pinout matches.

2

Enable E-Bike Mode

Enable Communications configuration vector bit 10 (Enable Ebike).

3

Set Protocol

Set Display protocol (port 1) or Display protocol2 (port 2) to match your display.

4

Configure Assist

Set Assist mode source to 2 (Display).

5

Enable Walk Mode

Set Walk mode signal source to 4 (Display) and enable Features bit 11.

6

Set Wheel Parameters

Configure Wheel diameter (mm), Wheel speed sensor source, and Wheel speed sensor pulses per revolution.

Bidirectional Throttle

Available in firmware 6.025+, bidirectional throttle allows one side for forward driving and the other for braking or reverse.

Bidirectional Throttle Configuration

1

Set Sensor Source

Set Throttle sensor source to match your analog input.

2

Configure Forward Voltage

Move throttle fully forward and set Throttle full voltage to that reading.

3

Configure Reverse Voltage

Move throttle fully to reverse/braking and set Throttle off voltage to that reading.

4

Set Fault Range

Configure Throttle fault range for fault detection outside the voltage range.

5

Set Endpoint Deadband

Configure Throttle deadband threshold for maximum command at endpoints.

6

Set Midpoint

Configure Bidirectional Throttle Midpoint (address 1987) to the resting position voltage.

7

Set Neutral Zone

Configure Bidirectional Throttle Deadband (address 1988) for neutral zone width centered on midpoint.

8

Configure Behavior

Set Reverse_Enable_Source and/or Regen brake source to 4 (bidirectional throttle) and enable corresponding feature bits.

9

Enable Feature

Enable Features4 bit 11 (Bidirectional throttle).

Rolling Start

Rolling start delays motor power until reaching a specified speed, useful for sensorless operation and certain pedal sensor configurations.

Rolling Start Configuration

1

Enable Rolling Start

Enable Features bit 9 (Rolling start enable).

2

Set Start Speeds

Configure start speeds based on assist mode:

  • No assist mode: Use Rolling start speed
  • With assist modes: Use Rolling start speed 1, 2, and 3 for respective assist levels

Recommended Setting

Set start speed to 0.5 km/h or greater minimum. Testing determines the appropriate level for smooth power delivery.

External Speed Sensor

Clutched motors require an external speed sensor since motor RPM is 0 until assistance begins.

Alternate Speed/Power Modes

The BAC controllers support two configurable power and speed modes: Race mode (default) and Street mode (secondary).

Mode Selection

The active mode depends on input state:

  • Input inactive: Race mode (default)
  • Input active: Street mode

Alternate Power Mode

1

Enable Feature

Enable Features bit 10 (Alternate power limit enable).

2

Select Input Source

Set Alternate power switch source to your input.

3

Configure Power Limits

Set power limits for each mode:

  • Rated motor power (Race mode PAS power)
  • Rated motor power (Race mode Throttle power)
  • Rated motor power (Street mode PAS power)
  • Rated motor power (Street mode Throttle power)

Power Ordering

Race mode power must be set higher than Street mode power.

Alternate Speed Mode

1

Enable Feature

Enable Features bit 8 (Alternate speed limit enable).

2

Select Input Source

Set Alternate speed limit switch source to your input.

3

Configure Speed Limits

Set speed limits for each mode:

  • Vehicle maximum speed (Race mode PAS max speed)
  • Vehicle maximum speed (Race mode Throttle max speed)
  • Vehicle maximum speed (Street mode PAS max speed)
  • Vehicle maximum speed (Street mode Throttle max speed)

Available Input Sources

  • Cruise/Digital input 1
  • PFS/Digital input 2
  • Brake 1/Analog input 2
  • Brake 2/Analog input 3
  • Remote power switch (Remote Digital Commands bit 6)
  • Remote speed switch (Remote Digital Commands bit 5)

Key Parameters Reference

Assist Level Parameters

AddressParameterFunction
200Assist mode sourceInput source selection (0-11)
201Assist low voltage readingLow assist voltage threshold
202Assist high voltage readingHigh assist voltage threshold
203-211Assist gain 1-9Power gain per level (pu)
212-220Assist speed 1-9Speed limit per level (pu)
221Momentary Assist SourceDigital input for button
222Momentary Assist ModesNumber of assist modes

Cruise Control Parameters

AddressParameterFunction
1930Cruise Enable SourceInput source bitmask
1931Cruise Input Mode0=Momentary, 1=Latching
1932Cruise minimum speedMinimum speed to engage (km/h)
1933Cruise Motoring Torque LimitMax motoring current (%)
1934Cruise Braking Torque LimitMax braking current (%)
1935Cruise Disengage ThresholdsSpeed deviation limits

Walk Mode Parameters

AddressParameterFunction
230Vehicle jog speedWalk mode speed limit (km/h)
231Walk mode signal sourceInput source selection
232Speed regulator Kp for Walk modeWalk mode Kp
233Speed regulator Ki for Walk modeWalk mode Ki

Reverse Parameters

AddressParameterFunction
1936Reverse Enable SourceInput source selection
230Vehicle jog speedReverse speed limit (km/h)

Next Steps