The MegaSquirt Project has experienced explosive growth other the years, with hundreds of new MS installations occurring every week - a phenomenal success! MegaSquirt has been successfully used in all aspects of Internal Combustion engine applications including R&D, Industry, Race, and Research. The MS project has transformed itself from a simple R&D project into a full-featured mature engine control system. To reflect this the support structure has also changed to meet the needs of MegaSquirt Users.
Moving forward, the R&D forums for MegaSquirt project are in a read-only mode - no new forum posts are accepted.
However the forums will remain available for view, they still contain a wealth of information on how MegaSquirt works, how it is installed and used. Feel free to search the forums for information, facts, and overview.While the R&D forum traffic has slowed in recent years, this is not at all a reflection of Megasquirt users, which continue to grow year after year. What has changed is that the method of MegaSquirt support today has rapidly moved to Facebook, this is where the vast majority of interaction is happening now. For those not on Facebook the msextra forums is another place for product support. Finally, for product selection assistance, all of the MegaSquirt vendors are there to help you select a system, along with all of the required pieces to make it complete.
A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
Could this dialog be advisory? I note is says, "With standard build."
Jim,
Yes, this page doesn't have any actual settings at all, it is purely there for users (mostly me!) to have a quick text reference to the pins, circuits, and amp pinout when trying to figure out things like which spare port is connected to which ampseal pin. Since you have moved things around at he 25x2 header, much of the info won't apply to you, and don't worry about it at all.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Paddle Upshift is still using PT6 for an input instead of AD4. I pulled the jumper and applied 5v and the indicator toggles to "upshift off". Right now I'm not sure how to change that.
PT6 is Output4 for clutch2 solenoid SL2 on EGT2.
According to my test notes, I do have a signal at VR2 on Paddle Upshift: 5v going to 0v when activated, same signal on Paddle Downshift which works. However, where the port assignment for P-down hasn't changed, the one for P-up comes through VR2 to port AD4. When I run the Input test the state does change. When the test is deactivated the indicator shows paddle upshift activated, which would be with the input pulled to ground. The gear indications are still pretty wonky but maybe that will be better after the paddle upshift is working right.
On the Brake Sense AD7-GP4, applying 5v to AD7 toggles the brake indicator to "ON". I am getting no signal change at GP4 so I know where to look. Either the external circuit is not connected or the circuit GP4 is not configured right. That should be a fairly easy fix once I get a chance to work on it. My suspicion is that the input circuit is configured for a 12v "ON" signal and the switch is connected to ground the input. I'll have to look again at the switch pins. I'm not getting any backup lights either, and I remember some confusion when I was making those connections. (check the fuse first of course)
I'm showing LED 1 OFF, 2, 3 and 4 ON which should output a "1", but again I know where to look. I can test voltages at the connector for the DRO and feed signals at the same point. I'm using a CD4511BE driver and HDSP-5703 segmented display. I don't know why there would be a mismatch but apparently there is one. Possibly an incorrect ground reference.
And then I have the CAN bus to verify.
On testing the solenoid outputs, I have a v2.00 TranStim board but no components or AMP connector for it. I'd have to add LEDs and test points for the rest of the solenoids but I guess I could do that. Looks like with just Out1, 2 and 3 that'd be 6 more LEDs and test points which is why I never built it. Probably take another month. Any suggestions?
The upshift paddle is most likely a code problem. I will look at it as soon as I get a chance (we have visitors from the other side of the continent at the moment).
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
I have the brake sense hooked up now and am getting a 5v signal at the jumper terminal from GPI4 to AD7. It also changes the indication in the program from Brakes OFF to Brakes ON so that's all good. I had a wire I hadn't hooked up yet, so nothing too complicated.
I had a diode get hot on one of the off-board solenoid drivers, taking it's signal from PAD04. It's dead so I'll have to swap that out. So I think I probably should wait for the software change before doing any more testing.
I have replaced the 1N4742 output zener. It's a 12v zener, and I wonder if maybe a 15v zener might not be a better choice since battery/system voltage can go at least that high under normal operating conditions, in some systems maybe occasionally as high as 17v. I'm sure an additional 5v or so would make no difference to the counter-emf spike when the solenoid field collapses and with PWM solenoids that could potentially be occurring hundreds of times a second. I think it might enhance reliability. Just a thought.
My next task will be to provide signal voltages to the DRO via the LED pins in the harness side of the AMP connector. I think maybe I can use a 9v battery to do that but I need to re-famiarize with the DRO circuit and build instructions. It seems to me there was something in that which didn't go exactly according to plan, maybe a polarity issue. So once I have that done I'll have a better idea of what is needed to get the DRO and the MShift to play nice.
I've run into a mess with the digital gear indicator, and it's going to take me some time to get that sorted out I'm afraid. Seems I went above my pay grade on densifying the parts. The end was a slick little unit that plugged right into an existing hole in the dash and had a 1/2" tall number for the gear behind a smoked window, along with a red window for the O2 sensor LED and a button to calibrate it, and the whole thing potted with rtv on the back side. But something didn't quite work out. Between initial assembly, testing, potting, and installation some wires must have touched somehow and now it's an unusable partially ripped apart mess on my desk, while I try to come up with a better way to do it.
In retrospect maybe I could have used the decimal point for the O2 LED, and spread things out a bit more. I think I may have another housing to start over with but that's going to take some looking. The original was destroyed in the disassembly process.
Well, I never really expected to make the annual British V8 meet in May anyway and setbacks like this are just part of the process, but it is a bit disappointing nonetheless.
-------------------------------------------------------------------------------------------------------------------------------------- Lance, while you are in there swapping the code for PT6 and AD4 (I'm sure it isn't quite that simple), could you also look at what needs to be done to allow the output of up to a 250ms pulse on PT6? From my notes, this drives solenoid SR which is used as a shift "Trigger". From the factory literature, a fault code is generated if this output stays either high or low, putting the controller into a limp mode. We also see from the truth table that this solenoid is used during every shift. Therefore logic dictates that it must be a pulse. The transmission is capable mechanically of shifting in as little as 50ms so the window for the pulse should be something in that vicinity, though possibly the required pulse is much less. However it is unlikely that another shift could be triggered in much under 1/4 second and if a longer pulse works hydraulically it could possibly improve the reliability of the shifts. I would prefer to start out with a wider range and decrease it once we know what works if that's OK with you.
By the definition of the output as a "Trigger", my interpretation is that the timing should be such as to initiate the trigger after the other shift solenoids have been "set" to the next shift state. This indicates a delay between setting the solenoids and releasing the trigger, resulting in the question of how long that delay should be.
Again, going to the OEM literature, the transmission should be capable of completing a shift in as little as 50ms (Blazingly fast, at the time of production F1 transmissions could do it in 25ms), but a typical automatic shift might take as long as 100-200ms. Part of this difference had to be due to the shift trigger delay, and no doubt partly from reduced shift solenoid PWM for softer shifts. The question is how much delay is optimal? Again, if we have the ability to set that delay from 0 to 250ms initially, we can decrease it to optimum during testing. I see no particular need to use a table here as I do not expect the trigger delay to influence shift firmness.
I THINK that is the extent of changes that we will need to the code. Of course testing should reveal all once we can start. I understand this is probably going to require more coding that you were expecting to have to do and for that I really do apologize. I had no idea when this all started that such a thing as a shift trigger even existed. And, since Marty hasn't put in an appearance here for quite some time I may now be the only person even using this transmission, though I did email him a few months back and he still had his project. I hope us getting this to work will encourage others. It really is a very fine transmission with fantastic ratios and will handle gobs of torque while being narrow enough to fit tight spaces. If GM would have had a 7 or 8 speed when I started this a few years back I'd have tried used theirs, and I don't know how many similarities there are in the control schemes, but the big OEMs do tend to borrow a great deal from each other so hopefully much of what we do here will apply.
Anyway, thanks again for your able assistance. I'll be here.
Jim
Sorry for the delay, I have been very sick for several days, and I am afraid to touch the code when my head isn't clear (been there, done that, got the messed up code to prove it!).
I'll get back to normal service as soon as I am healthy again.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw