Asked October 7 2014

Community Question

I finally got a joystick (game controller). It works well linked up to the Sabertooth H bridge control to control the G=Bots two drive motors but -due to the weight and high cg of the G-Bot - I'm going to need much precise and variable control.

Can anyone point to a tutorial that may give suggestions (script, other controls, or a combination) that will allow me to achieve this?

Also, the axis of the joystick control is 90 degrees off what I want. Is there an easy what to change that?

What about custom assigning other buttons for other functions? I've gotten the soil sampler to deploy with a joystick button using Rich's E switch and I've experimented with using some other simple script to try and achieve control of the torso rotation control motor using joystick 2 (using a diverse electronincs H bridge) but, again, I need much better control (variable speed and direction ramping, etc). When I tried to add another H bridge control to control the torso rotation with joystick two, EZ Builder won't allow more that ONE Movement Panel at a time? What's up with that?
E Switch

Is there anything like a primer on how this all works? (specifically: what is scripting? Is it a language? , how does serial motor control work?, advantages of using PWM vs serial with available premade controls?)

I know I have much to learn to get the G-Bot where I want him by Halloween and I'm not even really sure where to start.

Any help ans suggestion much appreciated as usual.

October 7 2014
I'll take a stab at one or two of the other questions while Rich gets some sleep:)

Simplest one first.


I didn't know an H bridge could be in anything OTHER than H bridge mode

Most can't, but the Sabertooth and Roboclaw both have multiple modes, and the Parallax HB25 acts like a big modified servo.

Sabertooth and Roboclaw have an R/C mode that also is supposed to look like a big modified servo, but so far no one here has gotten it to work well that way (of course, we were all trying with a V3, might work in a V4).

Rich's instructions were for the L298N that is sold here and is fairly common for an H-Bridge, but requires more connections than a Sabertooth in Serial mode, which only requires one digital port for serial commands. I don't know how to wire it for PWM how many additional ports it needs. I'll know in a couple of months when I start working with mine, but that will be too late for you. However, someone else may chime in here with more details.

October 7 2014
Before I sleep... The sabertooth speed control is based on the serial data sent to it. I don't have the actual numbers in front of me but I am pretty sure that if you send 1 it is fastest in reverse, 127 is slowest in reverse, 128 is stop, 129 is slowest forward and 255 is fastest forward.

There is a post somewhere with a simple (and crude) script I wrote to vary the speed of a sabertooth with a joystick using a variable and EZ-Script. The forum search should find it.
October 8 2014
I appreciate all the help everyone. Keep the suggestions coming...

I have much to assimilate...:)

On a lighter note, I got a chance to load test the G-Bot this afternoon.. Halloween is going to be fun!

G-Bot Load Test
October 13 2014
Thanks for the help again guys...
October 13 2014
Gwen, love the load test! Makes me wish I was a toddler again and had you around with your leg section. Maybe in a few years down the road when I have trouble getting around I'll turn my leg section into a really cool old guys cart. *cool*