I now have a working wireless adapter for my A9 for use with the RealFlight simulator! Total cost was ~$15!
1. Minima Compatible 5ch RX
$13.13 @ hobbyking
2. Molex Picoblade Lead
$1.20 @ hobbyking
3. 1K Resistor $1.19 @ radio shack
4. Heatshrink (laying around)
5. Hookup wire (laying around)
6. Interlink Controller (comes with RealFlight sim)
7. Interlink Cable (comes with RealFlight sim)
1. Soldering Iron
2. Multimeter (to check some voltages)
3. Heat gun (for heat shrink tubing)
Step 1: Prepare the Interlink to send 5v out
The first step in this process is to do a minor modification of the interlink controller. Don't worry, this is simple and not scary. You'd have to think of a way to make this break the interlink.
This is to install a wire from the USB 5v power to the trainer port connector on an unused pin. This will directly power the RX, so no other connections are required.
First, open up the interlink with the 4 screws on the back. Next, pick up the board sitting on top (it's not screwed down at all) that holds the trainer port connector.
Solder the hookup wire to pin #1 on the back of this board. This pin will contain the USB 5v output.
Next, solder the other end of this wire to the 5v terminal on the main board of the interlink where the input USB cable connects. Be careful here not to make any unintentional connections. You don't want to short any terminals here!
Now, put the interlink back together and button it up.
Step 2: Disassemble the Interlink cable end
The interlink cable with my RealFlight version (5.5) comes with an interlink cable that is in 2 pieces. The first piece is longer, and has the Futaba type trainer connector on one end, and a 1/8" (3.5mm) male mono connector at the other end. The second piece has a 1/8" (3.5mm) female mono connector at one end, and another Futaba style trainer connector. We want to leave the longer interlink cable intact so we can still use it for direct connection to the A9 if that's ever necessary again. The other part of the cable is only used if you're connecting up a Futaba TX to the interlink, which I'm going to assume you don't care about here.
So the first thing to do is to pop the back of the Futaba style connector off. On the front side there are 2 gaps hiding tabs. Stick a little screwdriver in there (carefully), and release those tabs. The backshell should rotate up and off of the connector.
Once that's off, you can see the 2 wires soldered onto the pins of the connector. Note: The above pic is for the long side of the interlink cable, which has different connections than the short side.
Push up the loosely fitted heat shrink on these wires, and then use the soldering iron to remove them from the connector.
Step 3: Soldering up the connector
Now we need to solder up the Molex Picoblade lead that connects our clean connector to the Minima RX.
The finished lead will need to be secure in the 6 pin connector, which means you will need to add some layers of heat shrink to it to make it clip closed securely. For me, 3 layers of shrink made a really good fit. Do this now, if your shrink won't fit over the little molex connector (otherwise you can do it later).
Next, solder the molex lead to the connector. Pin 1 is the power (red), pin 2 is ground (brown), and pin 6 is the signal (yellow). For reference, the pin numbers are molded into the connector right by the pins. See the above pic to see what this looks like.
Now, here's a tricky bit. Thanks to Simon Chambers for this fix. Some of the early minima 5ch RXs have a bug that makes them go into bind mode as soon as they are plugged into the interlink via the above wiring connections. The fix requires hooking up a 1K resistor to the signal and ground pins. Do this now, being careful not to connect anything you don't want connected with blobs of extra solder (that never happens to me
). Newer RXs may not require this fix. Alternatively, Simon is offering to update the code on the older RXs to the latest stuff if you send them to him (small shipping fee involved).
The above connector is ready to button up!
Step 4: Binding
See the instructions for the minima compatible receiver for this.
Step 5: Cleaning up
I used a tad of hot glue to attach the RX to the lower part of the finished connector back shell. I intentionally left the top part clear so I would have some place to grip it to remove it from the interlink.
The finished product:
It works great! Now to sneak my laptop into the office and hook it up to the big projector in the conference room for some practice at lunch...