You might be interested to know that you can actually test a throttle position sensor using the Arduino and just three wires.
The hall effect sensor I tested was a throttle position sensor from an early EZGO RXV. This sensor uses a 5V supply from the controller, then returns the modified signal to the ECU, and uses a ground from the controller.
By connecting the Arduino's 5V supply and ground to two of the pins, you can then connect the signal pin to an analog pin on the Arduino and map the voltage to a known value between 0 and 1023. A little simple math and you have a throttle percentage.
Considering how expensive the sensors can be, and the fact that the RXV for example has no less than three of these sensors, it can be a pretty valuable little tool. You could also use the Arduino to replace the brake and throttle sensors and convert the cart from the stock pedal controls to any control interface you wanted.
Why would you want to do that? Perhaps you have a handicapped individual who cannot use their feet. Remapping the controls to levers on the steering wheel would allow them to drive the car and retain all of the original features without adding complicated levers or mechanical systems to push the pedals. You could actually remove the pedals entirely.
I can post more details if anyone is interested, otherwise just thought I would share a little experimentation. I did it since we don't have an oscilliscope at our dealership, and was looking for an easy way to test hall effect sensors off the cart.
Thanks. Good tips and great ideas. I have be lazily day dreaming about a cruise control system for my TXT. Seems like your method would work well for that.
I was also thinking about replacing the key ignition switch with this keypad I have left over from other projects. Arduino would be the brain. Perhaps it could be the interface to cruise control as well. Just dial in speed and/or throttle position. Brake would disengage cruise control just like a regular car.
Sweet, nice little project. I just made a tester with a led, a resistor, & a 7805 regulator. With alligator clips to hook to a couple batteries. Where is the third sensor on a RXV? (throttle, brake, ??). I think the TXT is different than "just a hall effect sensor". The yamaha drive uses the same sensor as RXV.
The EZGO ITS sensor is not a Hall-Effect sensor.
ITS stands for Inductive Throttle System and an iron slug rather than a magnet enters the sensor.
Here is a block diagram and a schematic diagram, and a copy of the Patent, which contains theory of operation.
These work on the principle of variable Inductance. The iron slug increases the coil inductance when it's inserted into the coil. No contacts to fail. More reliable in nasty conditions than a pot. There are many products out there that work on this principle.