Glad you got this sorted, I had responded in a few placed to this and was about to share a blog post I’m putting together on this, this is not finished and I will be sharing on the main blog once done but my help.
Ardurover Setup & Configuration with Sabertooth 2x32 & Cube Autopilot.
I have slowly been working on a scout rover build and though I would share some info as I have not seen a lot posted with this setup especially for the Sabertooth motor controller from Dimension Engineering.
The idea of this project is a low level scout rover with FPV and front object avoidance.
The parts used for this build are
- Servocity Prowler Rover Chassis
- Hex Cube Purple & Carrier Board Mini
- Mauch HL Series BEC & Current Sensor
- Sabertooth 2 x32 Motor Controller
- Herelink
- Here GPS
- LED Torchlight
- Camera TBC
At the heart of this build is the Cube Purple Autopilot that’s mounted to the carrier board mini, this gives a compact setup with all the inputs I need, the Purple is ideal choice for this compared to the Cube black and others as its only single non isolated IMU.
This is then controlling the Sabertooth 2x32A Brushed motor controller, I choose this for its vast range of features that include
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Simple Switch configuration for basic setup
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Dual channel motor driver capable of supplying 32 amps on each channel with peak currents up to 64 amps per output
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Multiple Inputs - PWM radio control, analog, TTL serial or USB.
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Regenerative drive and braking.
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Operating modes include tank/skid or traditional mixing, Inputs have automatic calibration range calibration, expo options and multiple modes.
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Auxiliary controllable power outputs allow the Sabertooth 2x32 to operate from a power supply without a parallel battery, or automatic control of electromagnetic brakes 8A Max.
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5V 1A Aux output for accessories
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Enhanced configuration options via PC or Mac Application.
Autopilot Setup
As shown in the top image the Cube is fitted with Here GPS and is powered by Mauch HL series BEC and current sensor, Herelink is connected to the Cube via UART and SBUS, the Herelink Air unit is powered by the 5V output on the Sabertooth.
The Cube drives the controllers via PWM outputs that are connected from servo channels 1 and 3 to S1 and S2 on the driver, you should also note you need to also connect a ground wire from the 0v output on the input screw block to one of the ground pins on the servo header.
Motor Controller
The Sabertooth has some standard basic configurations assigned to the 6 switches located on the PCB, for most RC type applications the “Radio Control” config get you close but you will need to set switch 4 depending on your motor configuration and switch 3 depending on your battery setup.
Standard Switch Config
For my rover I have set it up for skid/tank steering with left and right motor being wired in parallel.
The config for this starts with the “Radio Control” setup shown above however switch 4 is set to “Independent” or “Off”, this means input S1 will drive one motor channel M1A & M1B output and S2 drive M2A & M2B .
If you wanted to use it with more traditional steering via a servo you would leave it set switch 4 to “Mixed” or “On” .
Ardurover
In Ardurover you will need to ensure your remote is properly connected and calibrated, you can follow the guide on this https://ardupilot.org/rover/docs/common-radio-control-calibration.html
To set the correct motor outputs from the autopilot you will need to configures the servo motor outputs to send the signal to the motor driver, depending on your setup it will generally be one of 2 ways, skid or separate steering and throttle.
For my setup with skid steering this would be
- [SERVO1_FUNCTION] = 73 (Throttle Left)
- [SERVO3_FUNCTION] = 74 (Throttle Right)
For other steering types you should follow the setup recomendations on https://ardupilot.org/rover/docs/rover-motor-and-servo-configuration.html
Ardurover Control Modes
By default rover will set the mode to “Hold”, this will prevent any control movement even when armed, you will need to choose the desired mode to use the rover, “Manual” mode will generally be the best place to start to check proper functionality of the system, in skid mode this will correctly move both output 1 and 3 as you move your sticks.
Satbertooth Aux Output
The Sabertooth also has two open collector outputs that can sink upto 8A each, these can be configured to be either switching or variable power outputs based on the input A1 or A2, these need to be specially configured in the DEScribe application in PC or Mac. These can be used to drive brakes, fans, solenoids, valves, heaters or similar medium power devices.
I have used one of these output to control an onboard LED light, this is configured as Servo output 4 is set as a switched output and is connected to A1, then in DEScribe I have configured.
Note these are open collector so you need to connect the positive to battery and the negative via the output.