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Sabertooth Kangaroo

by Dimension Engineering

Movement panel for the Kangaroo and Sabertooth from Dimension Engineering.

Requires ARC v2 (Updated 4/5/2021)

How to add the Sabertooth Kangaroo robot skill

  1. Load the most recent release of ARC (Get ARC).
  2. Press the Project tab from the top menu bar in ARC.
  3. Press Add Robot Skill from the button ribbon bar in ARC.
  4. Choose the Movement Panels category tab.
  5. Press the Sabertooth Kangaroo icon to add the robot skill to your project.

Don't have a robot yet?

Follow the Getting Started Guide to build a robot and use the Sabertooth Kangaroo robot skill.

How to use the Sabertooth Kangaroo robot skill

Movement panel for the Kangaroo and Sabertooth from Dimension Engineering. This allows a robot with wheel encoders to be used, which enables the kangaroo's speed control and various other features.

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Configuration

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1. Software Serial Option Checkbox This uses any EZB digital I/O port to send an emulated serial signal to control the Sabertooth. This section includes a drop-down for the serial communication speed (baud rate) and a Button to change I/O ports. *note: Software serial should only be used if the ezb does not have hardware UART.

2. Hardware UART Option Checkbox This uses an EZB UART port to send a serial signal to control the Sabertooth. This section includes a drop-down for the serial communication speed (baud rate) and another drop-down to select the hardware UART number.

*Note: Use the ezb hardware UART if available over software serial. 3. PC COM Option Checkbox This uses a PC COM port (commonly a USB-to-Serial device) to send a serial signal to the Sabertooth to control it. This section includes a drop-down for the serial communication speed (baud rate) and another drop-down to select the COM port number. This option has the unique feature that allows you to connect the Sabertooth motor controller directly to a computer.

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Configure the max speed values for each direction of each channel (Left & Right)

Kangaroo Dip Switches

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The kangaroo will need to be configured for Digital input, Quadrature feedback, velocity control, and independent mode.

Kangaroo Tuning

Use the Auto Tune feature to tune the kangaroo for the robot encoders. Because Auto Tune is a little unreliable at times, use the DEScribe software to verify the settings. If both wheels use the same encoder style, then it's probably a good idea to copy the settings from one encoder to the other, so they're the same.


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USA
#1  

Had one of these a while back and had a lot of problems. will dust it off and see if it is worth keeping.

PRO
Synthiam
#2  

I had a lot of problems setting it up the kangaroo with sabertooth for a movement - I don't know if it's worth the hassle depending on the robot chassis. If it's a custom chassis with decent quad encoders then it might be worth investing the time to get speed control.

You had a sabertooth or kangaroo or both?

When i tuned the encoders with their software, the values were totally wonky and different between each channel (left and right wheel). So i took the values from one wheel and copied them to the other. That actually ended up working.

Also, I had some issues with the encoder because the sensors weren't close enough to the wheel to measure ticks - so that's a thing.

#3   — Edited

Ya, the Kangaroo is a tricky device. The autotune is a little tricky if everything isn't just right. However once you get a successful tune it's rock solid and works great. I suggest you use the DeScribe software to tune with and not the onboard tune button.

PRO
Synthiam
#4   — Edited

Thanks dave - i used the DEScribe with the auto tune. I never bothered with the onboard tune button. Once I got the DESCribe auto tune to give me some values, I tweaked them.

It's working really well right now, actually. I wouldn't say it was great to start with though. Not sure if i'd use it again lol.

BTW, here's the thread of the problems I had with it: https://synthiam.com/Community/HackEvents/DJ-s-Test-Bots-TurtleBot-3-and-K-8-20483

#5   — Edited

Ya, it can be a real pain to get going. Depending on your setup it can be  nightmarish or a breeze.

The Roboclaw is built just as nice with the same features. It also has an auto tune. I've never used it but I've always wanted to give it a try. Maybe it is easier to get a proper tune.

All I know is that if the tune was left to me I'd never get close to the proper PID, speed and dead-band settings. LOL. It's easier for me to struggle sometimes with a auto tune then spend days or weeks getting all those setting correct.

I checked your link to the problems you were having. What a nightmare. I shared a few ideas based on my experiences in that thread.