What protocol does Shimano di2 uses

[ixiz]

Where can I find more information of what protocol Shimano di2 uses to change gears I would like to add an additional switch so I can change gears at the different hand position

[Doug Landau]

On Tuesday, January 10, 2017 at 8:42:04 PM UTC-8, ixiz wrote:
> Where can I find more information of what protocol Shimano di2 uses to change gears I would like to add an additional switch so I can change gears at the different hand position

bluetooth

[ixiz]

I dont think so - its not wireless

[lou.h...@gmail.com]

On Wednesday, January 11, 2017 at 5:42:04 AM UTC+1, ixiz wrote:
> Where can I find more information of what protocol Shimano di2 uses to change gears I would like to add an additional switch so I can change gears at the different hand position

Is that not a standard feature and buy extra switches from Shimano?

Lou

[ixiz]

YES and no - where i want to put the switches is not standard and not available

[Andre Jute]

On Wednesday, January 11, 2017 at 4:42:04 AM UTC, ixiz wrote:
> Where can I find more information of what protocol Shimano di2 uses to change gears I would like to add an additional switch so I can change gears at the different hand position

CAUTION! The Di2 I have is for touring bikes and automatically controls hub gearboxes and active, adaptive suspensions. There is a separate computer control centre powered by the hub dynamo, with its own very small energy storage, which is part of the system. My Di2 is therefore likely to be different from and certainly more expansive than the cut-down Di2 on weight weenie road bikes. How fundamental the differences are I can't tell. You can get a fuller description at
http://coolmainpress.com/BICYCLINGsmover.html
if you're interested.

HOWEVER: The Di2 on my bike also has manual override modes, and when I reengineered the bike to suit me better shortly after buying it, I had to fit new electrical control cabling because the designer or the engineer on the prototype I bought had cut everything too short for me for the sake of a "sporting" appearance. Counting the control wires and the subsequent successful tests and operation of the redone wiring led me to conclude that the Di2 (again, on my bike anyway) operates a simple mechanical binary system, a left-off-right signal to the stepper motor and this was borne out by the self-centering rocker switches supplied for the manual control. (Before the usual railroad minds on RBT now whine that a three-position switch isn't "binary", they should put their minds in gear. The switch sends only two signals: plus voltage and minus voltage, which then drives the stepper motor in its two different rotary directions. The central position on the switch is a convenience null: no signal is sent; the stepper motor doesn't need to be told to do nothing because that is its default state.)

I were you, I would start testing with an on/off switch in the wiring, and see in which direction it drives the stepper motor. Or, if you already have a spring loaded toggle or rocker, attach the wires and see.

MORE CAUTION! Unless you have considerable micro-electronic soldering and testing experience and skill, good eyes and a steady hand, have factory replacement wires with the right plugs already on them standing by before you start work -- and work on the spares, not the wires on the bike that are necessary for its operation, or work with jumpers. I suspect that on a road bike the Di2 wiring will be ultra-lightweight and nasty to work with, read fragile.

This is a project fraught with disaster, so I'm not responsible for anything that goes wrong on your bike, and I imagine your LBS will take the same attitude, as will Shimano.

Ignore idiots who claim it uses Bluetooth; it's not a wireless system, though, if you're working on it anyway, and you know what you're doing, it can easily be made wireless: I'm holding a Bluetooth sender/receiver set in my hand that weighs apparently nothing and is less than half an inch to a side. Not suggesting that you do it, though; even if you don't already have plenty of stuff operating on Bluetooth on your bike, within a year or two the air around it will be foul with Bluetooth transmissions. On my bike already the iPhone is the centre of too many operations.

Andre Jute
Technofondler

[cycl...@gmail.com]

The bluetooth is now a system on a chip I believe and you can buy them from Digikey.

[James]

I have no idea, but if I was to design such a system I'd investigate the
possibility of using CAN bus. A very similar tech is used for
automotive automation.

--
JS

[Doug Landau]

http://www.competitivecyclist.com/shimano-ew-wu101-di2-wireless-unit

[Andre Jute]

According to the blurb at that link, the Bluetooth permits the derailleur to send information like cadence to the head unit. It says nothing about two-way communication, such as sending commands wirelessly to the derailleur. What the OP wants to do is to send commands to the derailleur.

Andre Jute
Electronic chatter is not necessarily a symptom of intelligence

[Doug Landau]

Similarly, the rigidly consistent taking of chatter at face value does not necessarily reveal a lack thereof.

[DATAKOLL MARINE RESEARCH]

Does the switch wiring use silicone wires ?

[Andre Jute]

I made a pun on the Shimano acronym Di2, Doug. That's *exactly* not taking chatter at face value, the very opposite in fact.

So what are you on about?

Any event, I wasn't speaking to you, I was speaking past you, as indicated by putting the crack in the tagline to my sig. Come to think of it, Di2 itself contains a further pun, but I'll leave Shimano to explain to you.

Andre Jute
I hate explaining jokes, so I don't

[Doug Landau]

> I made a pun on the Shimano acronym Di2, Doug. That's *exactly* not taking chatter at face value, the very opposite in fact.
>
> So what are you on about?
>
> Any event, I wasn't speaking to you, I was speaking past you, as indicated by putting the crack in the tagline to my sig. Come to think of it, Di2 itself contains a further pun, but I'll leave Shimano to explain to you.

<CHURCH LADY>
Oh! Nevermind :-)
</CHURCH LADY>