ECU / ECM test bench / engine emulator

[tarar916]

hi
i am trying to make a simulation of the sensors of electronic fuel injection system engine. the value of the sensor will be fed to the ECU via keyboard on the computer and i am using AVR atmega 8535 for the serial interface. the problem is there are too many sensors including simple potentiometer outputs and also square waveform generators like crankshaft sensors. i am not sure how to control the outputs of these all sensors with my controller. the options i know of are PWM and DAC but both require massive effort. what can be the most efficient way of controlling all these sensors.
and if i have to use more than one controller would that be adviseable.is there any other way i can do all this.
thank u for ur help

 

[Resqueline]

Some people have built it with discrete analog components but using some microcontroller would make it far more versatile. I would have thought that most any would be up to the task, especially if using separate pot, pulse & D/A chips. I don't have much experience there though & don't know what you mean by "massive effort".
Old ECM's uses real slow CPU's and separate PWM & A/D chips to relieve the workload.
You might want to check out this site.
I for one would be interested in a cheap & simple to make & use test bench.

 

[tarar916]

hi thanks for answering
by massive effort i mean to say that i am using two port of the controller for the serial interface to the computer and emulation of the crankshaft sensor and camshaft sensor.
and i am left with only two 8 bit ports that can be utilized for DAC conversion option. which req of course multiplexing owing to the no of sensors
and if i use PWM on each pin to simulate the sensor then it req heavy computing on the software partcontrolling each pin (and probably going to the assembly language level)
the outputs of the sensors have been checked and noted and there is no confusion in these and i can control each one indivaidually but problem comes when integration arrives.
so please advise me what can be the best alternative and if there is any third option available please let me know.
thanks

 

[Resqueline]

I'd try to find a suitable multi-channel 8-bit D/A converter and use one port for addressing and one for data. But that sounds too obvious, maybe you found a hitch.
Many of the guys at the forum I mentioned are very knowledgeable, if you manage to get something out of them.