[intervigil]

So I've spent a bit of time trying to figure out how the M3 DCT shift LEDs work so I can light them up in my 328. Over the course of this I've burned out what appears to be 4 of them.

From what I can experimentally determine:
LED Vcc = 4.3V
Red LED Vforward=1.7V
Orange LED Vforward=1.8V
There is a 127 Ohm resistor connecting to a TI 6C596G4 shift register (datasheet) used to sink current (this controls how the LEDs turn on/off, more on this later).

V=I * R, so it looks like these LEDs are operating with ~20mA normally.

The LEDs themselves look like 22mm x 14mm (20mm x 14mm?), but I'm unsure about the packaging type.

I'm about to order some replacements with the above specs, but I was hoping to find out if anyone knows what the part (or compatible part) is already.

As for what I'm doing, it seems like the cluster already sets up power for the LEDs, the only thing needed to control the LEDs (for instance, with an Arduino reading the RPM from OBD pin 9) is to control the shift register.

[starfox5194]

Are you trying to make the shifter work like it would normally, but in a 328 auto? That's a neat project. Can you post photos of what you found tearing down the shifter? I might want to buy one too and help out.

EDIT: Looks like you would have to change out the shift lever too. Might be too complicated for me.

[mweisdorfer]

Originally Posted by intervigil

So I've spent a bit of time trying to figure out how the M3 DCT shift LEDs work so I can light them up in my 328. Over the course of this I've burned out what appears to be 4 of them.

From what I can experimentally determine:
LED Vcc = 4.3V
Red LED Vforward=1.7V
Orange LED Vforward=1.8V
There is a 127 Ohm resistor connecting to a TI 6C596G4 shift register (datasheet) used to sink current (this controls how the LEDs turn on/off, more on this later).

V=I * R, so it looks like these LEDs are operating with ~20mA normally.

The LEDs themselves look like 22mm x 14mm (20mm x 14mm?), but I'm unsure about the packaging type.

I'm about to order some replacements with the above specs, but I was hoping to find out if anyone knows what the part (or compatible part) is already.

As for what I'm doing, it seems like the cluster already sets up power for the LEDs, the only thing needed to control the LEDs (for instance, with an Arduino reading the RPM from OBD pin 9) is to control the shift register.

Well.... you will have to speak English 😂, but I get a lot of 335i guys would love to get a hold of an m3 DCT cluster and make it work as a shift indicator for the track...

[intervigil]

Update: I worked out how to drive the M3 DCT cluster's lights.
There doesn't turn out to be too much modification necessary to the M3 DCT cluster itself. You need to attach 8 leads to the ground pins of the LEDs and ground the LED you want to light to get it to light up. Most decent electronics repair shops can do this, or you might be able to talk one of the folks around here who mod clusters to do it for you.

I'll post a complete write-up with the schematic and Arduino sketch I'm using once I get the parts in to convert the 12V RPM signal from the OBD2 port to 5V this weekend.

> I get a lot of 335i guys would love to get a hold of an m3 DCT cluster and make it work as a shift indicator for the track...

Yup, this is pretty much what I'm working towards, except I have a 328.

[intervigil]

Put up schematics and source code here: https://github.com/intervigilium/bmw...t_shift_lights

I got the Arduino, development board, 5V buck converter here: https://www.chippernut.com/store/p31/Chipperkit.html
The rest of the parts can be found on Digikey (See the github link, there's a BOM file with the part numbers).

Pictures and video as follows:
Full system test video (pardon the weird RPM levels, I set them rather low to not annoy the neighbors)

M3 DCT cluster ground points. Ignore the leads in the image here, I had them removed and leads attached to the circled test points instead. Each test point controls 2 LEDs in the pair. Each LED pair is connected in series. The red line shows how the +5V power rail on the cluster is routed/connected. The black lines show how the LED grounds are connected to the test points.

View post on imgur.com

Enclosure with Arduino and RPM input circuit, light control circuit, 5V buck converter. Red/black twisted pair is +12V power/ground, single red wire is +12V tach signal. There are 2 4-pin JST SM connectors for the 8 LEDs.

View post on imgur.com

Cluster and enclosure prior to installation. I used 2 pairs of 4-pin JST SM connectors to connect the LEDs to the cluster.

View post on imgur.com

Removed OBD2 enclosure, tapped pin 9 to get the RPM tach signal to the single red wire pictured.

View post on imgur.com

Installation with zip tie to the back of the driver footwell area, near the group of wires going through the firewall. Cables route from the cluster area down through the dash easily. The twisted red/black pair leading to the top right of the image is for power. Pins 9 (+12V) and 18 (GND) of the cluster connector are tapped for those.

View post on imgur.com

[mweisdorfer]

You should sell those to members who want one

[intervigil]

Problem is that the bit inside the box takes me something like a day to make (soldering, crimping, etc), and that doesn't account for modifying the cluster to connect. It should be possible to give the circuit schematic to someone and get a custom PCB made for it, but I'm not really too experienced there.

[starfox5194]

Thanks so much for sharing your work!

Why didn't you solder directly to the onboard TI 6C596? Does it drive other LEDs than the DCT ones?

Also, any idea where we can source a cheap DCT bezel? looks like the cheapest way is to get a DCT cluster on eBay for ~300 USD

[intervigil]

> Why didn't you solder directly to the onboard TI 6C596? Does it drive other LEDs than the DCT ones?

No, it doesn't drive other LEDs, but it does receive clock signals from the board, synchronizing the clock signal with the Arduino, board, and TI6C596 is a lot more tricky, as the TI6C596 is expecting a single clock source. Spending the extra couple cents for another TI6C596 proved to be a lot easier.

I am not sure where cheap DCT bezels might be found. You might have better luck asking the members here who do cluster mods, perhaps they have a source?

[Hotter]

Was your Shiftlights enabled in instrument cluster menu?



And have you tried to send CAN BUS message for Shiftlights to activate? It seems its sent from M3 DME, not DCT (not sure what message data should be though).

CAN_ID_HEX      CAN_ID_NAME     CAN_ID_NAME (Translated)        DIAG_ID_HEX     SG_NAME
0x206   Steuerung Anzeige Shiftlights [1]       Control Display Shiftlights [1] 0x12    DME1

Maybe this would activate M3 cluster Shiftlights on non-M3 car without any hardware modification?

[starfox5194]

Hotter

That looks interesting. Where did you find this can ID?

I just ordered a DCT cluster, so I will be looking to see if there is a CAN-based solution to get this working in my 335.

I will see if I can send any values to 0x206. Does anyone have access to an M3 so that we can sniff the packets sent with ID 0x206?

As a side thought - I have an auto transmission, and it might be cool to only enable the shift lights in manual shift mode.

[starfox5194]

Nevermind, I found all of the information needed and more

Check out this guys github.

https://github.com/superwofy/E9X-M-C...ion-Module.ino

https://github.com/superwofy/E9X-M-C...gration-Module

Thanks superwofy!


For more info - see ***********

https://*********************/thread...and-more.8483/

[intervigil]

The shift lights on my cluster are not activated on the kombi. This is a hardware-only modification that drives the shift lights out of band from the kombi itself.

Driving the lights over CAN would be a lot easier, looking at the github code it seems fairly straightforward to do once something like a CANBED is connected to read the RPM and send the right activation message.