Another little project...

Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198450
Good design is when there is nothing left to take away. I revised the circuit to use the existing fuses and that allows me to dispense with the polyfuses which cost about £2 each. The motor live feed is now taken from the switch sockets and the relay is removed but the contacts are shorted with a link.
by minimax

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Replied by LanderMG on topic Another little project...

Posted 2 years 9 months ago #198451
Will be interesting when it's all done, in situ and working as expected.
I have ordered remaining parts.
Great work and thank you for updating with progress.

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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198457
Yes, that's it. The contacts into the switch sockets needed to be inserted a bit more bravely and now everything bobs up and down nicely. I have connected the switch earths to the bodyshell earth on the console with stout wires crimped into a big ring terminal and run a spare 18" of earth cable into it as well, because it is always good to have a decent earth for testing available. I connected the ignition feed to the window relay socket and bridged the relay contact, which now serves as the live supply. The only thing I have not done yet is the rollup on locking - purely because I haven't yet found a terminal to tap into without cutting into the loom.

I did make a brief video. It is on youtube. Cecil B. de Mille I am not! " MGF one touch windows " is the imaginative title.
Last Edit:2 years 9 months ago by minimax
Last edit: 2 years 9 months ago by minimax.

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Replied by LanderMG on topic Another little project...

Posted 2 years 9 months ago #198459
So has the diagram changed, or the parts list?

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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198460
Not significantly. The polyfuses are deleted and the connections to the relay board from the +12V supply now come from the switch sockets.
I shall publish a revised diagram next week once I have completed in car testing and found the right place to connect the indicator wire.
by minimax
The following user(s) said Thank You: BruceTF135

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Replied by BruceTF135 on topic Another little project...

Posted 2 years 9 months ago #198465
I have been really intrigued by this project; it's just the sort of thing I love. I have a fair bit of amateur-level analogue electronics experience, having worked a large part of my life as a technician in an eletctrophysiology lab. But digital stuff I have no experience of at all.

Well done!

The youtube video gets the idea across but gives no insight into what you have done.

If you are redoing the schematics and stuff, maybe you could make it a full 'how to' for the forum. I'm not sure exactly what's involved but one of the admin can probably advise. I'd be interested in having a go although I too would need help with the programming side of things, in exchange for a couple of beer tokens maybe :-)

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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198468
Thank you. What I have done is disconnected the motors from the switches and put a black box between them that interprets the switch commands and uses those to switch the motors through relays. It reads the time a switch is pressed to decide whether it was a one touch or a normal command. Because it can do what it likes with the relays, it can be programmed to recognise the super locking instruction and use that to roll both windows up.

This works on the early MGF. Later cars have a Rover one touch which is discarded and the Pektron cars will need to have their motors disconnected from the BCM as well as the switches and have new motor wires run in from the black box. I do not expect the BCM to throw a hissy fit if the window system is disconnected but I have not tried it on another car.

There is also the issue of connectors. The early cars use good Christian 1/4" terminals but the mark two and TF have specialised pluggage that will need to be connected to. If I were doing it, I would cut the switch wiring out of a scrapper with a good nine inches of free tails and wire them into the box. It may be more difficult to make this wholly reversible and I shall need access to the later circuit diagrams and ultimately to other cars if I am to develop it further.

I'm nearly happy with what I have, The rollup timing needs a bit of revision to work reliably and that will be part of next week's work. The hard part will be the design of a PCB which will be needed once more than five people are interested in having the system. It is pretty embryonic right now. As a how to, it is pretty much an electronics project to build and quite probably some way outside most owners' comfort zones. It may be easier to create a kit with comprehensive fitting instructions.
by minimax

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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198469
Having looked at the circuit diagrams, the TF will almost certainly be suitable for conversion. A custom switch harness and a couple of leads to the window motors will be necessary but that ought not to be a problem. A second fuse will be required for the driver's side but that isn't a difficult thing to add.
by minimax

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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198470
I have spent some time revising the software to slim it down a bit and make the shutdown routines a little more predictable. I need to run this in the car a bit more before I am happy that it is bomb proof. I think I might look at reinstating the window relay so that the circuit will be fully unpowered at switch off. As it is, a stuck relay would switch the motor on and off until the battery went flat so I think I will need to design a fail safe into it.
by minimax
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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198479
The revised software is proving ok so far but I am having difficulty with the rollup. I have it connected to the hazard light switch and two flashes of that roll the windows up every time but when trying it from the keyfob, the second flash is not picking up. One flash of the hazard first and it will work off the first flash from the fob. Odd. Still I know that in any project, the last one per cent is what takes ninety nine per cent of the effort! Time to frighten it with the 'scope.
by minimax
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Replied by Airportable on topic Another little project...

Posted 2 years 9 months ago #198483
I'm with Bruce 135 on this one, for me it's the first really interesting project, apart from the sphere re-gassing, thats been on the forum for a while. Thank you & I'll be having one of those when you're ready. AP
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Replied by minimax on topic Another little project...

Posted 2 years 9 months ago #198484
The current state of play is that once the car has been locked, the fob needs to be pressed again within a second or it will not deadlock so last night I re wrote that bit to monitor the flash input for three seconds before switching off completely. This ought to work and then I have all the functions. The final job will be to store the approximate window positions so it won't work the motors too hard in one touch or rollup mode.
by minimax
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