I read and followed through the tutorials and guides on the assembly part. When i tried to run the robot, it worked. But there was a problem, 2 wheels on one side of the robot was moving even though i did not move it. Where should i troubleshoot it from? I triple checked the connections and still couldn’t find the problem. Can anyone enlighten me? Thanks in advance. 
Hi GreenTea,
I thought there was something in the tutorial about this, but I did not see it. The issue often is that the not all Sabertooth controllers are exact in that a pulse width of 1500 is the zero point. Some may be 1498 others may be 1505… So sometimes the code has to be calibrated to the controller…
For now I will assume you are using ps24wd1.bas. In there look at the code that looks like:
ldrive=((lvert*GEAR) + 1500 - (GEAR *128)) ' Forward / backward
rdrive=((lhori*3) + 1500 - (3 *128)) ' steering
Now try experimenting, with the 1500 value here on the side that is creeping along. Try changing it to 1495 does that make it better or worse. If worse go the other way like 1505…
Good Luck
Kurt
I tried it and it was tedious at first. But nonetheless, it worked! 
The final value that made it stationary was:
ldrive=((lvert*GEAR) + 1448.5 - (GEAR 128)) ’ Forward / backward
rdrive=((lhori3) + 1453 - (3 *128)) ’ steering
Thanks a Million Kurt!!
Oh, i have another question to ask. I need to integrate the robot with a GPS module EB-85A & Digital compass HMR3300. I need to know whether the Bot Board II is using RS-232 or TTL levels at Ports 0 to 12. Can anyone help? Thanks in advance!
Glad you got it working.
BB2 is TTL on all pins (except the RS232 9 pin connector which is associated with S_IN and S_OUT). Most all are 5v output except P6/P7 which are 3.3v output but 5v tolerant. This data can be found in the Basic Atom Pro 28 datasheet which you can download from the basic micro web site.
Kurt
Thank you so much for all the information, really appreciate it!
Instead of using the PS2 controller to maneuver the rover, I am thinking of using a laptop. The laptop will be able to communicate with the rover through a wireless micro-controller, Rabbit RCM5400W. The rover will be integrated with a GPS module FV-M8 and a Digital compass Honeywell HMR3300. Can i directly use the connection S1(Channel 1) and S2(Channel 2) of the sabertooth to connect to the pins of the Rabbit RCM5400W? In this way, i will not be using the Bot Board II anymore. Or must I connect S1 & 2 to Bot Board II then connect a port from it to RCM5400W so that I can move the rover wirelessly through a laptop?
Thanks in advance, GreenTea 
RC5400WM.pdf (1.86 MB)
Probably not directly. The rabbit RC5000 appears to be 3.3v logic. The com pins MIGHT be 5v tolerant, I didn’t see it straight off hand.
I’m assuming you’ll be using a serial mode. S1 and S2?
Alan KM6VV
Pin 37/SMODE 0 and Pin 38/SMODE 1 at rcm5400w is pwm compatible from the manual. I am thinking of using these two pins to link with S1 and S2 of the sabertooth.
My question is:
Should i directly connect S1 and S2 from the sabertooth to rcm5400w?
OR
Should i connect S1 and S2 from the sabertooth to the Bot Board II and from Bot Board II, connect it with rcm5400w?
I am just afraid my components will get “burnt”.
where do i get the tutorials and guides?
On the main Lynxmotion site… Click on “Information” on the left and a list of the assembly guides, How To’s and other documentation appears. Here is a shortcut to the page LynxMotion Information
thank you. and do anyone know how do i connect the sabertooth to a rcm5400w?