I read the Sabertooth2x25 motor driver datasheet and in operating mode 1 its input range is 0-5 Volts. The E200 throttle has an output of 0.8-4.2 Volts so it is not compatible. From what I read in the datasheet it is my understanding that the Sabertooth2x25 requires an input signal of 2.5~0 Volts for reverse, 2.5 Volts for no movement, and 2.5~5 Volts for forward. This would require a self centering potentiometer to operate it, which are common in joysticks however I do not know of any handlebar mounted throttles that are self centering.
Im beginning to think that a potentiometer may be my best to control the speed however it might make for difficult one handed operation. what about a throttle that uses a potentiometer instead of a hall effect sensor. that could solve the issue. im only interested in forward motion at this time anyway.
i also have a small 5v joystick from a sainsmart balancing robot kit http://www.sainsmart.com/sainsmart-joystick-module-free-10-cables-for-arduino.html auto return to center. maybe this will work for a throttle
i really appreciate you working through this with me by the way. Thank You