Memory dump of ECU

[b3lha]

Originally Posted by TomsSVX

I took notice to that as well. The chip in the TCU could easily be removed and a programed chip soldered in... Nothing very complicated at all, which has blown my mind as to why no one has done it yet

Tom

Yeah. I have a modified TCU file that should allow switchable power mode on UK/Euro/Aussie cars. I'm going to give it a try once I'm absolutely sure I know what I'm doing.

[b3lha]

Calum,

I've modified the circuit as per your comments. Could you have a quick look at it and confirm that it's OK now?

The pictures in my previous posting are linked to my website and have been updated.

[Calum]

No problem, will do.

[b3lha]

For the sake of completeness and as an addition to the posting I made in the power mode thread earlier, here is the part of the USDM TCU that governs how the power mode switch works. The corresponding parts of the JDM and UK TCUs have been posted further back in this thread. For those who don't know, the comments on the right hand side, after the semicolon are added by me to explain the logic.

Subroutine e6cc

e6cc 12 8a 02 16 brset (0x008A), 0x02, [0xE6E6] ; If TPS_Faulty goto e6e6
e6d0 12 3a 80 12 brset (0x003A), 0x80, [0xE6E6] ; If VSS_Faulty goto e6e6
e6d4 12 11 20 0e brset (0x0011), 0x20, [0xE6E6] ; If Cruise_Engaged goto e6e6
e6d8 96 4d       ldaa (0x004D)                  ; Stick_Position
e6da 84 07       anda 0x07
e6dc 27 0b       beq [0xE6E9]                   ; If stick in D goto e6e9
e6de 12 12 40 04 brset (0x0012), 0x40, [0xE6E6] ; If Manual_Switch goto e6e6
e6e2 81 03       cmpa 0x03
e6e4 25 03       bcs [0xE6E9]                   ; If stick not 123 goto e6e9
e6e6 5f          clrb                           ; Set Normal Mode
e6e7 20 4b       bra [0xE734]                   ; goto e734
e6e9 5f          clrb
e6ea 12 11 40 45 brset (0x0011), 0x40, [0xE733] ; If Power_Switch goto e733
....
Decide which mode to use based on Speed and Throttle
Go to e734
....
e733 5c          incb                           ; Set Power Mode
e734 d7 5a       stab (0x005A)                  ; Store Shift_Mode
e736 39          rts

We discovered today that on a JDM car, manual mode always overrides power mode. On a USDM car, manual mode only overrides power mode when the stick is in 1,2 or 3.

[Calum]

Looks good to me. One last suggestion, if possible try to verify you've got enough space around each of the rom chips to use this low cost ZIF socket-

http://parts.digikey.com/1/parts/297...28-526-10.html

rather than having to use traditional sockets. They may add an extra $10US to each board cost, but make removing and installing chips much easier. If you can't find them in the UK (I checked RS and Farnell, but they weren't listed on their websites) I've usually got a couple hundred in stock and can post you a couple. You might be able to get away with the cap above the rom on the left if you solder the cap on the bottom of the board and clip the leads down, or if its easy just push the cap out to one side like you did the other one.

Btw, you don't need to use that wide of a spacing for the cap leads either if you need the room, you can use a 100 mil spacing and use axial caps bent up in the air. Check out how I've got my caps setup on this board-



...that frees up a little board area, no biggie. If you end up doing that don't forget to order axial caps instead of radials.

Not related to your board, consider buying a moates.net burn1 rather than a willems or other cheapie ebay burner. Having owned both (and a much more expensive professional machine), the moates is worth the extra $50. Its just soooo easy to use, super quick, and never randomly burns chips up. The selection of chips it can burn is much less, but if you standardize on the 27SF512 that doesn't matter (and the 27sf512 is a good choice).

Check out how simple it is to use-

http://www.sr20forum.com/calumsult/1...tes-burn1.html

Twin zif sockets, board setup for both roms identical, moates.net burn1 = really really fast and easy chip flipping. Quick enough to even do between dyno pulls. You'll like it.

[Calum]

Hey b3lha, can you make the following measurements for me with your ecu?

From the center of the 27C1028 pin #14 (so bottom left), how far is it from there to-

-the board edge directly to the bottom
-the board edge directly to the left
-the standing board to the right (labeled SMP1 on my ecu)
-the canned oscillator top the top

If you've got a caliper that would be awesome, if not just ballpark with a ruler will work.

Btw, how did your board turn out?

[b3lha]

Hi Calum,

Are you confusing left and right? Or are you looking at the solder side of the board?

a. 5mm to board bottom edge (20mm to ECU case)
b. 18mm to board right edge (tight against side of ECU case)
c. 85mm to SMP1 board on left
d. 51.5mm to oscillator on top

Measured with a ruler.

Unfortunately I've been busy with other things recently and haven't had time to do the board. I modified the pcb some more, just moved things around a little to make enough space for the ZIF sockets. But I haven't uploaded the changes. What is the name for the piece that plugs into the 27C1028 socket? I thought it was called a DIL header, but all the ones I can find seem to have solder cups and don't look suitable for fixing to a board.

The board photo in your previous post looks very compact. I can't understand how you have managed to fit all the tracks in. Is that a potentiometer attached to it by the green wires?

[Calum]

I'll take a picture of the dimensions I'm referring to.

Yea, its a potentiometer. Thats actually part of the factory Nissan ecu, the wires go under the daughterboard. You turn the pot on the ecu to switch into diagnostic modes, and its directly connected to an ADC channel on the mcu. Weird, but Nissan used that for ages. There's actually a spot on the board for a pcb mounted pot instead of the large pot, and Nissan stuffs either the pcb pot or panel mount pot on different runs of the ecu, I guess based on whichever part happens to be cheap.

On the interconnects, take a look at the products offered by a company called Samtec. Digikey reps them and they sell direct. I think the BBS line is a board to socket, or you could just use standard terminal strips if your not using a socket.

[Calum]

I meant dimensions in the actual ecu. When you get a chance, can you print this off (make sure to print 1:1 ration, not fit to page) and verify it fits inside the ecu? The 28-pin socket-connector is on the bottom right, and the board sits in the ecu topside up.

http://www.calumsult.com/calumsu/dis...ze%20check.pdf

I've got all the components placed, and am about half way done with the routing. I've got the memory bus done which is the hardest part, just to finish up the rest of the junk now...

[b3lha]

I printed out the board. I'm fairly sure it came out 1:1, it is 100mm x 58mm and the pins of the 1028 are correctly sized and spaced.

The board does not fit inside the ECU.

On the right side there is about 1.5mm clearance - perfect
On the left side there is about 0.5mm clearance but this can be fixed by bending the SMP1 riser board slightly.
The top edge is obstructed by the oscillator. You need to shave off at least 4mm
The bottom edge is flush with the edge of the motherboard, but the ECU case is bigger than the motherboard, you could expand by up to 15mm if necessary.

[Calum]

Excellent!

[b3lha]

Huh? Excellent that it does not fit?

[Calum]

No, excellent that I've only got to make a small change.

[Calum]

Round 2! I trimmed the top edge about 4mm. Bottom, left, and right edges are in the same positions.

http://www.calumsult.com/calumsu/dis...ze%20check.pdf

Thanks!

[b3lha]

It fits!!!

The left and right side are fairly tight. Do you think it might be better to trim 1mm each side (if possible) to ensure it doesn't rub from the vibration of the car?

See attached photo.