05-11-2015, 05:48 AM
I have been reading your blog on Hacking the Ford ECU. for my OBD2 test bed or my Arduino. I am looking at creating a similar project but have a few differences and if you would be able to assist with the correct code and some technical info it would be great.
I need to recreate a signal to drive/trigger an ECU for an engine. I need to be able to test the ECU on a bench and without the correct cam and crank signal input this is not possible. The ECU uses inductive crank sensors runs along the flywheel which has 36 evenly spaced notches + 1 notch to indicate TDC (TDC Notch is between 36 and 1). The cam sensor picks up 12 evenly spaced peaks + 1 to indicate TDC (TDC peak between 12 and 1). The ECU will read this signal and convert it from an analog signal to a digital one. These sensors create voltages up to 50VAC depending on engine speed. I imagine that a voltage of 25-30V should be sufficient to power the ECU at all RPM ranges.
If i want to achieve an engine speed of 600RPM then I will need to programme arduino to send pulses at 360 Htz + 1. In other words one pulse every 10 degrees of engine rotation as well as one extra pulse at 5 degrees.
How would I write this code?
I am considering using something like the LM2577 DC-DC Adjustable Step-up Power Converter Module which will convert the 5V DC up to 35V DC which should be sufficient to power the ECU. I am not sure on the current requirements but will take some measurements next week. My only concern is if the ECU will recognise the generated wave and be able to trigger off it.
Below is a scope shot of the engine running at idle (600RPM) showing both crank(bottom) and cam(top) sensors.