Live Robot Hack Session
DJ Sures
Synthiam

Dimension Engineering Sabertooth & Kangaroo

When:
Duration:
17 people have subscribed to this event

I'll be connecting a Dimension Engineering Sabertooth to their Kangaroo and controlling via Synthiam's ARC robot software. We'll demonstrate how to turn a regular DC motor into a servo - and experiment with a wheel encoder.

#1  
I'll be there if at all possible. If not I will defiantly be watching after the fact. 

From the DE website:
Sabertooth:  Allows you to control two motors with: analog voltage, radio control, serial and packetized serial.
Kangaroo x2: Position or speed control, Quadrature encoder feedback or potentiometer feedback, 80,000 pulses/sec processing, Support for limit switches and mechanical stops, Analog, R/C and serial inputs, serial and packetized serial support.

A couple things I'd like to see demonstrated: 
Using an ARC Sabertooth Movement Panel to control the Sabertooth with and without a Kangaroo attached. 
Sending servo commands from ARC to control the Sabertooth with and without a Kangaroo attached.

The idea would be to find out what is needed to in ARC to control a Sabertooth with or without a Kangaroo. Which method is easier or more precise (either, both , or) for position and speed control of a DC motor using the Sabertooth with or without a Kangaroo. What it takes to operate a Sabertooth through ARC with or without a Kangaroo and why each method would be used. 

Right now I am sending Simple Serial Commands through the Uart Ports of EZB v4 to command a Sabertooth/Kangaroo to precisely move DC motors to certain positions at different speeds. The commands look like this:

Code:

uartWrite(1, 0, "1, p50200 s20996", 0x0d) #rotate half left
Sleep(3000)

uartWrite(1, 0, "1, p113261 s20996", 0x0d) #rotate half right
Sleep(5000)

uartWrite(1, 0, "1, p78200 s20996", 0x0d) #rotate to center postion
I've always wondered if simple servo commands would accomplish the same thing. Life has gotten in the way of my experiments and my personal robot is not operational for testing. 

If all this is above what you wanted to accomplish with your Hack I totally understand. What ever you do with this Sabertooth/Roo combo will be much appreciated by all. It's a wonderful setup once everything is tuned and working.
Synthiam
#2   — Edited
I’ll be limiting the demonstration to the correct way of combining a sabertooth and kangaroo together. and this does not use the sabertooth movement panel, it uses a servo control. 

This method does not use a sabertooth without a movement panel. 

I’ll only be demonstrating the correct way that combines both products. If you’re attempting to use a motor as a servo without a kanagaroo and potentiometer or encoder, then I recommend you revisit the physical design of your robot. But you’ll see what that means when you watch the hack:)
#3   — Edited
Sounds good and I understand. I can do my own tests soon and report back.

I look forward to seeing what you present.
#4   — Edited
Looking forward to see this!!
Probably will have to watch the archived version of it, due to my timezone!!:)

I see the ODrive being used a lot, what makes you prefer the Sabertooth? Just being curious!
#5  
I will be there I have a sabertooth and it will be interesting to see what I need to connect to ARC.
#6  
I'll try and join.  Will certainly watch after the fact if I can't (Friday nights are not great for me).

Alan
Synthiam
#7  
What nights are usually better for you guys? During the week? Cause Saturday is the only evening i don't work during the week
#8  
@DJSures  Any time and any day would be ok for me.  that helps you alot!   DJ I don't think it should be Saturday as that is your day off.  Maybe it could be earlier.  as this is only a guess  most people have more time during the Pandemic, and may not be working .  and Alan if is a hot date on a friday night, remember the 6 foot rule.  I was just kidding Alan.
#9  
Weeknights other than Friday are generally better for me, although don't plan around my availability.  I kind of prefer watching the videos after the fact so I can skip ahead and rewind, even though it means I can't participate in the live comments.

Alan