Has anyone wired up a Bosch fly by wire throttle body to megasquirt? What I have looks just like what is outlined on this page:
http://www.siliconchip.com.au/cms/A_103261/article.html
Basically, it's two potentiometers and a DC throttle control motor. I'm glad I was able to see one of these up close and take it apart, etc. But I wonder if it's a waste of time to pursue hooking it up? It would be a bit scary to drive, like my roomate's Volvo.
Fly by wire throttle control (Bosch)
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
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78Spit1500Fed
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This discussion has been made several times before... the consensus is that you would probably never get the functionality of the original system, rather it would simply be a cable replacement.
For the majority of vehicles, the throttle body is close enough to the throttle pedal to warrant the use of a cable.
Adding the complexity of two encoders, a stepper motor and stepper motor controller is probably not worth the effort for a simple cable replacement.
-Brian
For the majority of vehicles, the throttle body is close enough to the throttle pedal to warrant the use of a cable.
Adding the complexity of two encoders, a stepper motor and stepper motor controller is probably not worth the effort for a simple cable replacement.
-Brian
Perhaps the TPS can be configured to work with Megasquirt and I'll work with the throttle motor seperately. It has two encoders in the event of failure, so I imagine only one could be wired in a resistor network fed from the 5V supply. They don't make the throttle cable for my car/engine combo anymore. Due to issues with the headers and cable location I was considering this option. Anyway, I got it cheap so I'm ok with not using it.
I worked on an ETC (electronic throttle controller) for Borg Warner about 6 years back.
It is a rather complex algorithm that would probably go beyond what the HC08 or even star 12 is capable of. We had to use a Texas Instruments DSP (digital signal processor) to adequately run the throttle body.
In a nut shell, the algorithm used two sensors:
1) Throttle Position
2) Pedal Position
Using the pedal position, the controller would send out a PWM signal to the DC motor that would drive the spring loaded throttle blade. The throttle position sensor was used to verify position. We used a rather complex PID (Proportional / Integral / Differential) control strategy to lock in the position. Calibrating the gain values for the PID took a lot of time. When the values were off, the throttle body would either be really slow to react, or oscillate all over the place.
Another challenge is the power consumption. The DC motor used to drive the throttle bodies sucked A LOT of juice and would heat up rather quickly. You are going to need some rather serious power transistors to handle the current load.
In the end, it can be done… but I think it’s a little more difficult than most people would initially think.
It is a rather complex algorithm that would probably go beyond what the HC08 or even star 12 is capable of. We had to use a Texas Instruments DSP (digital signal processor) to adequately run the throttle body.
In a nut shell, the algorithm used two sensors:
1) Throttle Position
2) Pedal Position
Using the pedal position, the controller would send out a PWM signal to the DC motor that would drive the spring loaded throttle blade. The throttle position sensor was used to verify position. We used a rather complex PID (Proportional / Integral / Differential) control strategy to lock in the position. Calibrating the gain values for the PID took a lot of time. When the values were off, the throttle body would either be really slow to react, or oscillate all over the place.
Another challenge is the power consumption. The DC motor used to drive the throttle bodies sucked A LOT of juice and would heat up rather quickly. You are going to need some rather serious power transistors to handle the current load.
In the end, it can be done… but I think it’s a little more difficult than most people would initially think.