M3Evo 0 Posted July 12, 2007 Hello electronics wizards I'm in the process of trying to make a control system for a twin sequential turbo setup for my car. What I need in essence is an electronic system which can take probably more than one pressure input, a throttle position input and a crank speed input and give PWM outputs to three solenoid valves. These valves need to control the operation of a wastegate/exhaust divertor, a conventional wastegate, and lastly an air divertor valve. All of these things need to be operable by the ECU regardless of engine speed and load so there's a vacuum pump going on the engine to give a consistent source of operating fluid, but this means that things like the WGs can't just regulate them selves dependent on boost pressure as they normally would. If anyone can point me in the direction of something suitable or some reading I could do on the subject I'd be eternally greatful! As an aside, I'd use the PWM tables in the ECU to control these functions, except that only one of them can operate closed loop, and there are only two tables in any case Cheers! Alex Share this post Link to post Share on other sites
jackherer 543 Posted July 12, 2007 use a megasquirt? Share this post Link to post Share on other sites
M3Evo 0 Posted July 12, 2007 Would really like to keep the Emerald, although I guess an MS could perhaps be used for the solenoid operation? Share this post Link to post Share on other sites
Richie-Van-GTi 74 2 Cars Posted July 12, 2007 MS only has one masp sensor though, maybe you could add another in but then you will have to code it all up. Have you looked at ecu's from other cars that run twin turbo's as standard? Share this post Link to post Share on other sites
jackherer 543 Posted July 12, 2007 Would really like to keep the Emerald, although I guess an MS could perhaps be used for the solenoid operation? yeah I meant as a secondary controller rather than a replacement. Share this post Link to post Share on other sites
M3Evo 0 Posted July 12, 2007 Thinking about it, the code would need to be bespoke and that's what's beyond me at the moment so perhaps a PIC might be the cheaper way in the end. Share this post Link to post Share on other sites
M3Evo 0 Posted September 6, 2007 Right! Think I've been over complication my problem! I reckon that I can control two of the wastegates using the PWM tables in the Emerald (which is nice, easy and adjustable!) That just leaves the small matter of controlling the air divertor valve which needs just a pressure input and a PWM output. I've got a chip which has an analogue to digital input and a PWM output module......and that's all I've got unfortunately. Anyone know how to go about programming a PIC16F690 to take an analogue input and give a PWM output? Share this post Link to post Share on other sites
DougieSt 0 Posted September 9, 2007 Hey mate, Have you got a setup to program a pic? I could write you the code for a simple A/D->PWM function really easily. Have you ever used a pic before? They're great when they work... What specs on the inputs/outputs do you need? G'luck mate. Share this post Link to post Share on other sites
M3Evo 0 Posted September 11, 2007 (edited) Hey Dougie, I've got Microchip's PIC-Kit2 which comes with a PIC16F690. This is my first attempt at anything like this, I'm not exactly what you'd call computer literate! For the inputs I need just a 0-5v analogue singal from a little pressure transducer and for the output I need something like a 15Hz PWM signal which I guess would need amplifying so that it could drive a solenoid. I've probably missed off a load of vital info as I really don't have a clue what I'm doing Cheers for your help dude EDIT> Aah, the other thing I need to be able to do is to change the PWM output that any given input brings about so I guess that means having some kind of look-up table in there. Edited September 11, 2007 by M3Evo Share this post Link to post Share on other sites
DougieSt 0 Posted September 11, 2007 (edited) Hey Dougie, I've got Microchip's PIC-Kit2 which comes with a PIC16F690. This is my first attempt at anything like this, I'm not exactly what you'd call computer literate! For the inputs I need just a 0-5v analogue singal from a little pressure transducer and for the output I need something like a 15Hz PWM signal which I guess would need amplifying so that it could drive a solenoid. I've probably missed off a load of vital info as I really don't have a clue what I'm doing Cheers for your help dude EDIT> Aah, the other thing I need to be able to do is to change the PWM output that any given input brings about so I guess that means having some kind of look-up table in there. Not familiar with the 16F690, but I'll give the data sheet a look over. I'd say you could read directly from the A/D result register do a bit of maths to get the right duty range, then a straight right to the Duty register of the PWM hardware. Anyhoo, I'll check and let you know asap, give you a rundown of how you could do it. Also, If you only want 1 input and 1 output you could make a pretty simple circuit without using the PIC, but it kills flexability Edited September 11, 2007 by DougieSt Share this post Link to post Share on other sites
M3Evo 0 Posted September 11, 2007 That'd be awesome! I'm keen on the PIC as I reckon it would make 'mapping' the output relative to the input much easier than with an analogue type circuit. Cheers mate! Share this post Link to post Share on other sites
DougieSt 0 Posted September 19, 2007 Sorry I havn't done it yet. Uni is kickin my arse. I'll be giving it a go soon tho Share this post Link to post Share on other sites
M3Evo 0 Posted September 19, 2007 Wicked, it's very much appreciated dude! Share this post Link to post Share on other sites
