Inline D-Fly / Wireless Unit
The EW-WU111 D-fly allows your Di2 system to communicate wirelessly with your head unit and smartphone or tablet. It'll let you display currently selected gears, allows you to switch head unit screens, update firmware, change settings and more.
It is generally placed on road bikes, positioned somewhere outside the frame, or in your handlebars. Have a look at the attached user manual for examples on where to place this unit on your bike.
While Shimano officially do not recommend placing this inside the frame or handlebars, in most cases that'll work just fine. I personally have never heard of anyone complaning about signal strength due to it being installed inside the frame.
BT-DN110 / BM-DN100 required
The EW-WU111 / EW-WU101 wireless units are meant to be used with the BT-DN110 / BM-DN100 battery/mount and will not work with the older SM-BTR2, SM-BMR1 or SM-BMR2 batteries. The older SM-EWW01 will work with the older batteries, but only supports ANT+ (no BluetoothLE).
The unit has two e-Tube ports - one on each end - allowing it to be place in between two cables. Note that you do not have to connect both ends. That is completely up to you.
Shimano recommend you install it outside the frame, but it generally works just fine inside the frame too. This depends a bit on the frame material and distance to your head unit.
Here you can see GPLama install the wireless unit in one of his handlebar drops.
In order to connect the Wireless Unit to your mobile phone you will need either the E-Tube Project mobile app or the E-Tube RIDE app. The latter is meant to be used on E-Bikes, but it'll work on up-to-date road bikes too. Note that if you have never updated your Wireless Unit then it will only work with E-Tube Project.
Pairing a Garmin is relatively simple. The video below shows the process on a Garmin EDGE 830.
The same can be done on a Wahoo ELEMNT device:
And of course plenty of other bike computers, Sigma, Lezyne, Bryton, Mio and others all support Di2. You generally add the Di2 system through the sensors menu / page.
Warning: changed passkey? Close the app, forget the device
When you first start the E-Tube Project mobile app it'll ask you to change the passkey. At this point you can choose to either change the passkey from the default "000000", or not.
If you don't, it'll bug you to change it every time you start the mobile app and connect to your bike.
If you do change the passkey, it is very important that you do NOT update the unit's firmware. If you do, chances are it'll fail halfway through and render your bike unresponsive.
What you should do instead is:
- Close the app as soon as possible (using the disconnect button)
- Go to your phone's Bluetooth device list
- Forget / delete the EW-WU111
You can now open the mobile app again and connect to the bike. It'll ask you for the new passkey. It's now a lot safer to update the EW-WU111 firmware.
Still having problems with the Wireless Module? Read the Di2 Wireless Module // Bluetooth Troubleshooting Guide.