I am building hand controls for a D7R Dozer as I am a paraplegic. The simplest way to do this is to connect a microcontroller to the decelerator plug and emulate the sensor, the microcontroller being operated by an electronic trigger in the handpiece. To be able to do this I am hoping somebody can tell me what digital protocol is used between the decelerator sensor and the ECU. Thanks!
The sensor output to the ECM is a PWM type. Would it be possible to use the same sensor for the decelerator pedal as the one currently used in the tractor and simply relocate it to a convenient point for hand operation by extending the wiring harness.?
Interesting, what is the pcb with the chip next to the Hall effect sensor for if the signal is a simple pwm? As for relocating the sensor, that will be my only option in the case I can’t get this all working properly, before that though I would like to do a proper job without sacrificing any level of control.
Can you post a photo of what you are looking at. To me relocating the OEM sensor would be the easiest solution, because you know it already works without the need for any type of electronic intervention.
I don't have any pictures, but an aftermarket replacement I bought (which didn't work) had a hall effect sensor with a pcb and a microchip attached. I haven't pulled apart the OEM one, so I'm not actually sure what is in there. I will get back to you when I attach a microcontroller and verify the signal type.
Quite frankly I think you are creating a problem where one does not exist. Use the OEM sensor and simply mount it in a different location would be the simplest (and guaranteed functional) solution.
KISS principal. As Nige has stated the guaranteed modification to work is to relocate the OEM sensor to the hand control. The addition of extra inputs the the signal without isolation of the other input would result in conflicting signals. If you wanted to retain OEM decel pedal as well as a hand control, a change over relay or switch may work on the signal wire. Please keep us informed with your progress.
After more thought...... An oscilloscope hooked on the signal wire F702 Green should indicate to you what the voltage of the PWM output from the sensor is. Offhand I'm not sure. From experience of this particular OEM sensor the duty cycle will vary from close to 0% up to almost 100%. When measuring the output you should also be mindful of the fact that there are mechanical stops in the decel pedal mechanism that physically prevent the sensor moving through its full available range of rotation. Move the sensor past the "physical operating limits" imposed by the pedal (in either direction) and you will break it. Don't ask me how I know this.........
You also partake in the ooppsy learning!
Forgot my manners. Welcome to the HEF. Where a life time of swinging spanners and hitting sh-t with hammers does not compare to the knowledge of the members here.
You only do it once.......... Well if you have half a brain you do.
Well sometimes for me it takes 2 or 3