Hi,
I have a racing sidecar, it runs a motorcycle engine and electronics. I am currently working on a project which is a DIY data logger, this will read various sensors from the engine and log the details to an SD card using an Arduino. While investigating the wiring it seems that I broke the tachometer, so now I am trying to fix it.
The crankshaft position sensor is a Variable Reluctance type, Honda Part Number: 30300-MEE-D00. This produces an AC signal that the ECM can use to determine how fast the crankshaft is spinning. The crankshaft has 12 notches on it, so one revolution of the crankshaft would produce 12 pulses. I believe the voltage of these pulses increases as the RPM increases.
In order to display the RPM on the tachometer, the ECM sends out a 12V square wave signal to dash. After messing around with a multimeter trying to read the frequency of this signal, it is now no longer a square wave, it seems to sit around 1V at all times. The engine still runs, and is obviously still getting a signal from the crankshaft position sensor, the signal to the clocks is just broken.
What I would like to do is read the crankshaft signal, convert this to an rpm, create a 12V square wave at the correct frequency to display this RPM on the dash. I am thinking I could do this with an arduino, if I can make sure the input is 5V or below.
There are IC you can buy that convert the signal from a Variable Reluctance sensor, so I will be looking at getting a few of these. Then it would be how to figure out how to drive the Analogue tachometer. I've had a look inside the dash, there seems to be a MLX10407 chip, 3 connections of the motor that moves the needle are connected to this chip.
Do you think this is possible? Or do I need to buy a new ECM?
I have a racing sidecar, it runs a motorcycle engine and electronics. I am currently working on a project which is a DIY data logger, this will read various sensors from the engine and log the details to an SD card using an Arduino. While investigating the wiring it seems that I broke the tachometer, so now I am trying to fix it.
The crankshaft position sensor is a Variable Reluctance type, Honda Part Number: 30300-MEE-D00. This produces an AC signal that the ECM can use to determine how fast the crankshaft is spinning. The crankshaft has 12 notches on it, so one revolution of the crankshaft would produce 12 pulses. I believe the voltage of these pulses increases as the RPM increases.
In order to display the RPM on the tachometer, the ECM sends out a 12V square wave signal to dash. After messing around with a multimeter trying to read the frequency of this signal, it is now no longer a square wave, it seems to sit around 1V at all times. The engine still runs, and is obviously still getting a signal from the crankshaft position sensor, the signal to the clocks is just broken.
What I would like to do is read the crankshaft signal, convert this to an rpm, create a 12V square wave at the correct frequency to display this RPM on the dash. I am thinking I could do this with an arduino, if I can make sure the input is 5V or below.
There are IC you can buy that convert the signal from a Variable Reluctance sensor, so I will be looking at getting a few of these. Then it would be how to figure out how to drive the Analogue tachometer. I've had a look inside the dash, there seems to be a MLX10407 chip, 3 connections of the motor that moves the needle are connected to this chip.
Do you think this is possible? Or do I need to buy a new ECM?