DIY DI2

[manninen]

hello everyone
reading few of your stories and i think this is the place to ask about my project

i have plans to make 1x10 with di2 RD with just RD and of course handlebar cables (ok i could borrow it somewhere, i will use it only for tuning up the RD)

anyone know wiring schematics for "main cable set"

planning to use just some 7.4v rc car LI-PO battery, and put it inside seattube
i don´t mind about original connectors (even RD), i will solder the wires

so is it possible?

or just spend 760£ to buy RD, 2 cable sets, battery and charger for that

first picture: if i´m right i could leave battery and charger out right away if +/- are these

lets see where this is going to end

[concept64]

he I have done this one for the gest
the objectf whase to have compact baterie pack and you have a plug for recharge the baterie and the plug to the DI2 (we cant use both in the sime time)

the VIDEO
http://www.youtube.com/watch?v=SEjj5AJv ... ture=feedu

[pritchet74]

Yes, absolutely possible. I had a copy of the complete wiring schematic, but I don't have it anymore. Someone else on the forum has it - maybe he'll get a copy for you.

Have fun!

[manninen]

im not gonna use original battery
this is the one im thinking

and looks like with this frame is gonna be hard to get internal wiring, still trying of course
if no one has schematics i will go with original wiring

[skimons]

i found some info in their patents (look via google patents), but it is not 100% clear to me yet.
- blue wire = positon signal (both in front wiring and rear wiring)
- red / black = + / -
- there is a wire for shifting (green) to the FD and RD

I have to cut up the front kit to figure out what comes from the mP to the 5-point connection

I want to use a 200 mAh battery (16 grms), think it will last long enough. i will test it first (under a bulb, in case it will burn out)

edit: one other point: to connect to all points (RD, FD, battery, controller, shifters), you'll need suitable connectors as well. In your case this only applies for the RD. I doubt the availability of Di2 spare parts

[manninen]

wow google patents! skimons, you´re such a detective!

and answer to my own question

quoting keizen´s text "The top button is the Green/Black wires. The bottom button is the Green/Red wires."

hmm... leap forward again

i think blue, positioning is just tuning the RD, dont have to buy handlebar cable set if get information which colours does button on handlebar cable set together, it might be blue/black or blue/red

i could do it if i could just get RD wiring plug which has 10cm wiring to see RD pins/colors, anyone?

[Jeffr]

If you have a specific question about the di2 signaling I can answer it. I had to reverse engineer the whole thing for the di2 mtn serial shifter.

[manninen]

picture to that hole and which pin is which

[Jeffr]

Ah, that is a pain. What you can do is setup some jumper wires between the connectors so you can get a multimeter in there. Even better if you have a scope, as you can just hook up the signals and shift.

First identify power and ground. That should be relatively easy. Next to differentiate POS and RD signals, you can short power to the pin briefly while the RD is in a medium gear. It should shift when you find RD. The remaining pin is POS. POS is an output from the RD that gives a bunch of information including the current shift position. This is how the FD knows when to trim. Counter to popular conception there is no extra 'brain' in the FD. All of the units are fairly independent and perform orthogonal tasks.

I haven't done this to the RD myself so I don't have a map of that one. I do have a map of the 5 pin interface between the front and rear wiring harnesses.

[manninen]

i weren´t asking if i had RD and cables, thing is im trying to put 1x10 system with buying just a RD. if i could get those pins im gonna buy an RD and make wirings to it.

as i said in first post its easy to spent 200£ to original cablesets

hardest thing is to get wires connected to RD without proper connector

if somebody has di2 system its maybe 10min job to do this job with multimeter

[Jeffr]

I see, maybe I didn't understand your question. The connectors are shimano proprietary and not available elsewhere. You will have to cut up a wiring harness to do it.

[skimons]

I see, maybe I didn't understand your question. The connectors are shimano proprietary and not available elsewhere. You will have to cut up a wiring harness to do it.

thanks for the info's jeffr. must be honest that i was hinted to use google patents
instead of cutting up a complete wire harness, you could also order one of the following spares (from shimano's tech docs):
- 7E3 98010 junction cable (short)
- 7E3 98020 junction cable (long)
- 7E3 98030 rear der cable
- 7E3 98040 front der cable
available at madison.co.uk
but i fear you'll have to use the front wiring kit with the processor anyway

the RD cable also fits in the STI lever to act as a shifter pod connector

[Jeffr]

You definitely need the front wiring harness to generate the proper signals for the RD.

The shifters are just contact buttons. The front wiring harness converts those button presses to the actual signaling format used on the wire by the derailleurs.

[manninen]

i don´t think so, it seems to be usin ground - , positive + and green wires. only thing is now position, the blue one. do i switch it between blue/red or blue/black.

somebody has tried before that handlebar section is only needed for positioning

ok i can tell it´s only internet information

[Jeffr]

Sorry, that's not the case. I used a logic analyzer and reverse engineered it. The position pin is just used to auto trim the front and when adjusting the RD.

The RD takes one pin in that does both up shift and down shift depending on the waveform.