Hall-Effect sensor wiring

[Ricardo]

Hi everybody, I'm working on a school project which involves the conversion of a small engine to fuel injection, we bought a MS-II kit and have already assembled the board and got Megatune running on the PC. We also got some sensors working, however, our Hall-Effect sensor doesn't seem to send a signal to the Megasquirt.

We are using the wiring harness shown here: http://www.DIYAutoTune.com/catalog/1239 ... -p-43.html and this is how we figured it should be connected:

-"signal" wire on sensor to white wire going to pin #24
-"voltage" wire on sensor to pin #26 (we also tried connecting it to the 12V source)
-the "ground" wire to the same ground as the other sensors

We have tried everything and the RPM gauge on Megatune is still red, does that mean we did not connect the sensor properly? Has anyone gotten a Hall sensor to work with their megasquirt? Any help would be greatly appreciated

[Matt Cramer]

We've used a couple different Hall effect sensors with MegaSquirt before. This one may need a pull up resistor. Measure the voltage on the signal wire when there's a tooth in front of the sensor, and measure the voltage there when the sensor is not in front of a tooth. Let me know what you find.

[Ricardo]

Thanks for replying, I measured the voltage as you said and here is what the voltmeter says:

-With no tooth: 0.17 V
-With a tooth at the appropriate distance: 0.004V

We're using a trigger wheel like the one shown here: http://www.DIYAutoTune.com/catalog/361- ... p-182.html , it says they've tested it with VR sensors, do you know if it should work with a hall effect?

[Matt Cramer]

We're going to be running some tests with a Hall effect sensor as we've heard mixed results. However, in your case it sounds like your sensor simply needs a pull up resistor.