Toyota A-Series Transmission controller

[Kai]

Good News, everyone! Thanks to a few others jumping on board, the hardware design has reached beta, we have an idea of how we're controlling everything, and instead of an Atmel AVR - we're going with a Xilinx FPGA instead - this way we can tailor it to our specific application. Compared to the original atmel idea, it's a little more expensive, but minimally so and allows us to have fewer components on the board - each doing their own thing. For example, we'll be able to read the L1/L2/L3 outputs from the Engine ECU and deal with them directly - easier for plug & play!

The only issue we're running into now, is the software side of it. We need a flowchart, any 4-speed auto with a TC lockup should be fine, in order to get a start on the programming of the FPGA. Tables & maps are easy, and not needed, just the BASIC structure of 'how transmissions & their controllers work' - it's making my brain hurt!

Anyone able to help?

 

[mikeymkll7mgte]

One question... Will this be able to work with a standalone that does not output the L1, L2, and L3 signals?? I might be able to get some flow charts for the 4l60E and 4l80E as i know a guy that works at a transmission shop. Ill give him a call....

 

[Kai]

First design of it - no - we're tailoring this for the 7M setup first of all - if you can get those flowcharts - that'd be great, the sort of flowchart for software, not for fluid though!

 

[Kai]

Okay - no need for flowchart stuff - software is underway at last! However, if someone can answer a few questions, it's be much appreciated.

We've detailed all the inputs & outputs, which is simple enough, but, the one input we're having issues with, is the speed sensor - now, there are several different answers on how many pulses it outputs per revolution of the driveshaft, so if someone could clarify how many it ACTUALLY puts out, that'd be great. If its several pulses depending on the application, well, we could work all of them into software, and just make it configurable via a DIP switch.

Then, how to work that into pulses per mph - i presume it's just a case of math regarding the diff ratio vs rpm - but, again Geoff & I are a little lost on this, and its currently the only holdup.

The PCB is designed to be configurable by pretty much any idiot. Maps will be changeable via USB (simple matter of flashing), but will come preloaded with the stock maps, so it's plug & play. Some stuff will be configurable via dip switches or jumpers though - such as the PWM line pressure solenoid (which would have to be wired in separately). Ie, if you install the different valve body - all you have to do, is connect the wires from that one solenoid, direct to the PCB, and move a jumper. Simple, no?

 

[4U2QUIK]

I believe it's 1.2 pulses per revolution for the supra. Only reason I know this is because I had to get a supra speedo to work with a t56 that had a 17 pulse per revolution signal.
'm sure IJ has had to deal with the same issue, you might check wit hhim also.

 

[mikeymkll7mgte]

On the revloutions, it depends on if the car has ABS or not. If no abs, 1 pulse per revolution of the driveshaft. If it has abs, I think the tooth count is either 30 or 36. (I can count them in a bit and get an exact count for you as i have another "wheel" laying around.) Now.... this is assuming you are taking the signal directly off the sensor. The stock trans controller wants to see 1 pulse per revolution, so if the car has ABS, the 30 or so tooth count is sent to the ABS computer, then "translated" to a 1 pulse per revolution signal that is then sent to the trans controller. Either way, if you are making this plug and play, the signal going into the stock trans controller will be 1 ppr. There is also the speed signal coming in from the speedometer too.... but im sure you already knew that. I had to find the parts to convert both my transmissions to the 1 ppr because i have no abs computer to translate it, so thats how I know all this. Im very interested in this, as its been a real pain to get the stock trans controller to work with my MS2. If you need someone to do testing for one that works with standalone.... :wavey:

 

[IJ.]

32

 

[Kai]

Thanks guys - just what i needed to know!

 

[mikeymkll7mgte]

Damnit... IJ beat me too it. Yea I counted 32 also.

 

[IJ.]

Damnit... IJ beat me too it. Yea I counted 32 also.

<<< pretty quick for an Old Fart

 

[mikeymkll7mgte]

I would have beat ya... if i could have gotten back to my shop quicker!

 

[spencyg]

Very interesting guys. Admittedly I'm an electronics dunce, but I know enough to appreciate what is involved, and how powerful a few simple circuits and some clever programming can be. I'll be watching your progress closely. I had considered the Suprastick to be perfect for my own requirements, but if you come up with something better, I'll be one of the first in line to give it a go. Kudos to the forward thinking and "watch what I can build, not buy" approach. Love it.

SGinNE

 

[Kai]

Well this is the wonderful thing about Geoff - he's considered every possible angle. It's be a simple matter to update the FPGA code at a later date, to add 'flappy-paddle' capability, effectively just go full manual control over shifting, with auto control of the TC Lockup and line pressure (if A341 valve body installed).

Stuff like this keeps me occupied, i guess, i like to start projects, get building, and i admit that my first design, whilst simple enough to make, would not have been accurate. Geoff is a total nerd when it comes to digital electronics, whereas i'm more analogue based (i grew up without microcontrollers!). Now that the I/O is in place and defined, the code will be easy enough to implement. After the initial 'basic' program is laid down, it's a matter of fine tuning, and shifting code blocks around, and allowing code to be enabled based on hardware pullups (like the dip switch/jumper idea), to allow it to be entirely idiot proof, yet advanced enough for most people.

It won't rival a PCS by any means, as this is really a specialised design for 80's/90's Toyota's, BUT, with it being open source, it wouldn't be very hard at all to adapt it for almost any transmission, or application - remember, we're going for upto 6 solenoid control, all PWM capable

 

[IJ.]

Can only flappy paddle upshifts Kai.....

Mechanical limitation of the 340 design.

 

[Kai]

Good to know, thanks IJ

Just curious, how come you can't downshift?

 

[IJ.]

Just the way the Sprags are arranged it'll freewheel until the rpm's match.

Feels like a Trans fullOneutrals

 

[Kai]

Aaaah okay! Well then, flappy paddle upshifts will take a back seat then

 

[IJ.]

Works fine for upshifts but my way of thinking is if you have a programmable controller it's going to be a damn sight more consistant in D than you can ever be flapping a paddle

 

[Kai]

Flappy paddle is something i hate, but others might have liked it - in any case, it's not a priority, first up, is the extra solenoid control

 

[mikeymkll7mgte]

The consisteny thing is the reason I went auto. I lost a trophy race bracket racing a couple years ago due to a missed shift, and knew then I needed an auto. :icon_bigg Any idea how long its going to be until this is ready to roll out? Race season is almost here.... :evil2: