RC Mode Configuration with Buttons

By BasicmicroGetting StartedUpdated
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The RC mode of the RoboClaw motor controller lets a hobby radio transmitter and receiver drive both motor channels, either independently or mixed for differential drive. This guide wires the motors, receiver, and power, then configures RC mode using the onboard buttons found on older RoboClaw hardware.

The onboard configuration buttons are deprecated as of the V5 hardware revision and do not exist on newer boards. For V6 or newer RoboClaw hardware, configure RC mode in Motion Studio instead; see General Settings in Motion Studio.

RoboClaw motor controller with throttle and aileron receiver channels connected to the S1 and S2 headers
Figure 1: A RoboClaw wired for RC control with both receiver channels connected.

The RC mode of the RoboClaw motor controller allows an RC transmitter and receiver to control both motor channels of a RoboClaw. Each motor can be operated independently, or mixing can be enabled to allow for a differential drive scheme. This Application Note walks through the process of connecting the hardware and programming the RoboClaw with the onboard buttons.

What You Need

  • 1× RoboClaw motor controller (dual channel, V5 or earlier)
  • 2× Brushed DC motors
  • 1× RC radio transmitter
  • 1× RC radio receiver
  • 1× Battery for the RoboClaw
  • 2× Female to female servo cables
  • 1× Small screwdriver

Wiring the Motors

  1. Locate the terminals labeled M1A and M1B and loosen their screws. Wire the first motor to these terminals by placing one bare wire end in each terminal and tightening the screws until the connections are snug. The order of the wires does not matter for the first motor.

  2. Wire the second motor to the terminals labeled M2A and M2B. The order does matter for this motor. Note the color of the wire connected to the M1A terminal and connect the same colored wire of the second motor to the M2A terminal, then connect the remaining wire to the M2B terminal. Make sure all motor connections are secure and will not come loose from the terminals.

    Two brushed DC motors wired to the M1 and M2 screw terminals of a RoboClaw motor controller
    Figure 2: Two motors wired to the RoboClaw properly.

Connecting the Radio Receiver

  1. Locate the pin header labeled S1; this is where the output from the radio receiver connects. Using the receiver’s manual, find the throttle channel and connect it to S1 with a servo cable. Both ends of the connection are polarized: on the RoboClaw, the negative pin of S1 is toward the inside of the board, while the polarity on the receiver varies by model and is labeled on some receivers.

    One RC receiver channel connected to the S1 header of a RoboClaw motor controller with a servo cable
    Figure 3: One RC channel connected.

  2. Locate the pin header labeled S2. Connect the aileron channel of the receiver to S2 as done with the throttle channel, observing the same polarity.

    The RoboClaw powers the receiver from its onboard BEC through the 5V line of the servo cable. If the receiver is powered by an external battery or by the BEC of another speed controller, the 5V lead of the servo cables must be cut or removed entirely to prevent a conflict between voltage sources. The two diagrams below show both configurations.

    Wiring diagram of a RoboClaw powering the RC receiver through the 5V line of the servo cables
    Figure 4: The 5V line is connected between the RoboClaw and receiver, so the RoboClaw powers the receiver.
    Wiring diagram of an RC receiver powered by its own battery with only signal and ground wires to the RoboClaw
    Figure 5: The receiver is powered externally and the 5V line between the RoboClaw and receiver has been removed.
    RoboClaw motor controller with throttle and aileron receiver channels connected to the S1 and S2 headers
    Figure 6: Two RC channels connected to the RoboClaw.

Connecting Power and the Transmitter

  1. Identify the positive and negative leads of the battery. Find the two screw terminals on the RoboClaw labeled + and – and loosen their screws. Attach the negative lead first by placing it in the loosened terminal and tightening the screw until the connection is snug, then repeat with the positive lead.

    Battery leads wired to the positive and negative screw terminals of a RoboClaw motor controller
    Figure 7: Power wired properly to the RoboClaw.

  2. Turn on the radio transmitter.

  3. If the receiver needs to be bound to the transmitter, do it now while power is applied.

Setting RC Mode with the Buttons

There are two variants of RC control. In the first, two RC channels each control a motor independently. In the second, mixing is applied so that one channel operates both motors in the forwards and backwards direction while the second channel steers left and right with both motors.

  1. Locate the three buttons on the board labeled MODE, SET and LIPO. These buttons are used to configure the settings of the RoboClaw. Also note the three LEDs labeled STAT1, STAT2 and ERR; these are used for feedback while using the buttons.

    The MODE, SET and LIPO configuration buttons and status LEDs on a V5 RoboClaw motor controller
    Figure 8: The buttons for configuring the RoboClaw.

  2. Press and release the MODE button. The STAT2 LED will blink a number of times to indicate which mode the RoboClaw is in. Press SET repeatedly until the STAT2 LED blinks either once for independent RC control or twice for RC control with mixing. Press and release the LIPO button to save the settings.

    Animation of the button sequence for setting RC mode with mixing on a RoboClaw motor controller
    Figure 9: Setting RC mode with mixing.

Testing the Motors

  1. Test that the motors respond properly to each radio channel input. If mixing has not been set, the throttle and aileron inputs should operate each motor separately. If mixing has been enabled, throttle input should move both motors forwards and backwards and aileron input should cause the motors to turn in opposite directions.

    Loss of signal between the RC transmitter and receiver, either due to range or turning the transmitter off, can result in issues controlling a robot. Many receivers will continue to send the last known stick positions to the RoboClaw, which can result in a robot running away or crashing. Some radio and receiver combinations can be programmed with failsafe positions to prevent these problems; consult the documentation for the system being used.

Swapping the Control Channels

If the throttle and aileron channels are not the desired controls for the motor channels, they can be changed by moving the servo connections around at the receiver. The servo connections to the RoboClaw remain the same; note that motor channel 1 is associated with the S1 header and motor channel 2 with the S2 header.

Next Steps

With RC mode configured, the robot can be driven directly from the transmitter. These guides cover the current hardware and the full RC setup: