Turnigy 9XR telemetry mods By Mathew Prentis May 2013

Starting point is a standard Turnigy 9XR with a FrSky DJT module.

Original concept is from Mike Blandford “FRSKY Telemetry mods by Mike Blandford.” which is the telemetry mods using a MAX232 IC for a 9X. The 9XR has a different module interface board so the mod is slightly changed to get telemetry to works this is how I went about get Frsky telemetry on my 9XR.

As I will only describing making the MAX232 interface board and the mod to the 9XR module interface board you will still need Mike Blandford original instruction for the DJT mods and ATMEGA64A connections.Mike's original can be downloaded from openrcforums.com just do a search for “FRSKY Telemetry mods by Mike Blandford”

What you need.9XRFrSky DJT moduleUSBASP AVR Programmer lead (plus drivers for your system)

For Telemetry modMAX232 IC5x 0.1uF monolithic/ monoblock capacitors2k7 Ohms ¼ watt resistor470 Ohms ¼ watt resistorVeroboardhookup wire (rainbow or ribbon cable)

For connections on ATMEGA64Aabout 200mm of 0.3mm or 30 AWG wire 2x 220 Ohms ¼ watt resistor ( depend where the tracks are cut you can use the SMD resistors on the main board) Heat shrink to fit over ¼ watt resistors.

Firmware/ SoftwareThe original 9XR firmware doesn't have telemetry so you will need to flash new firmware to the 9XR. I've tried Open9x for “9X Radios with Fr-Sky telemetry modification” and ER9X-FRSKY both work ok. This firmware is suitable for both 9X and 9XR radios.

You will also need to download software for you computer so you can upload the new firmware onto the 9XR the two I've tried eepe and Companion9x both work.Plenty of information and videos on the net on how to use and flash your 9XR.

A big plus with this software is you can also copy, add, edit you models on the computer and import/ export from the 9XR using the USBASP AVR Programmer lead.

Hardware Mods

The telemetry signal from the DJT module is in RS232 Coms voltage levels and the ATMEGA64A processor on the main board need it to be in TTL levels. To convert RS232 to TTL we use a MAX232 IC.To get the signal from the DJT you could use a lead from the external port but I opted to use the two unused pins on the DJT module to connect directly to the 9XR mainly so I could use the external port for BlueTooth.The last mod is so we can use the spare communication port on the ATMEGA64A processor to read the Telemetry information.

Circuit diagram of the hardware mod, this is a copy from Mike Blandford document.

The trickest bit is the RS232 converter but an IC called MAX232 will simplify the job all you need is a few capacitors and it's done or you can buy one off the net an already assembled on a small printed circuit board.

The next few page shows how to built the converter on some veroboard.

RS232 converter using a MAX232 IC.

Cut a piece of veroboard 9 holes wide by 10 holes long.Using a 6mm or so drill cut the copper tracks as shown, it should only take a few turns of the drill to remove the copper so don't use an electric drill do it by hand.

Turn the board over and solder the wire links on first.Four links all on the right hand side I the white link is from the 5Volt track and the blue link connect to 0Volt track.

Solder the capacitor and the MAX232 IC in place then add some leads to go away. The bright yellow tube is insulation on C4 lead.

My lead wires whereRed = 5VoltsBrown = 0Volts (GND)White = T2out to RX of DJT Grey = R2in from TX of DJTGreen = MISO to 9XRYellow = MOSI to 9XR, this lead is cut has a 470 Ohm resistor soldered inline before it connects to the 9XR pin.

You can use any colour lead it doesn't matter as long as you keep track of what goes where.

Electrically insulate the bottom of the veroboard to prevent shorts, I used a thin bit of foam.

Remove the back of the 9XR and undo the screws from the module interface board it will also help if you unplug the lead to the Futaba plug (top right of the board). On the bottom right hand of the board are the pins that protrude from the back of the transmitter for the 2.4G module to plug into. The FrSky module doesn't use the second to top and bottom pins so these will be our connect points for the RS232 RX and TX from the DJT. Unlike the 9X transmitter the bottom pin (right side in photo) isn't grounded so no work required but the other pin is grounded so we need to cut the track on both sides of the board. If you look closely it look like a 4 point star so cut all 4 tracks with a sharp knife. These pin have a plastic separator which isn't shown here it's simply remove to gain access to the tracks then put back on after.

Repeat on other side of board, no plastic separator this side.

To check tracks are cut use a multimeter on Ohms scale and measure between pin and one of the two black wires on the top of the board, open circuit is what you want.

With the module interface board lifted out of the way slide the veroboard component side up into the void under the module interface board, its a bit cramped for room but it should lay flat to the front of the 9XR you can either side it forward so it's near the nut for the neck strap or slide it back closer to the main board.

You will need to trim some plastic from the top left and bottom right sides to give the new wires access to get out from under the module interface board. Trimmed enough plastic for the module interface board to lay flat when back in position.

Solder RX and TX connections from veroboard to bottom of module interface board (not the long pin side)

From veroboard (T2out pin 7 of MAX232 IC) solder wire to second from top pin the one the tracks where cut. In my case its the white wire. from veroboard (R2in pin 8 of MAX232 IC) to the bottom pin. In my case its the grey wire. Fit the module interface board back in place and screwed down. Pay attention to getting the wires in the void and ensuring the other wires from the veroboard exit through the cutout you made in the top left side.

If the module interface board wont sit flat don't force it.Check if the wires you just soldered have enough plastic trimmed away or try re-arranging the wires.

With the module interface board back in place solder the 5Volt supply.

0Volts (Gnd) from the veroboard gets soldered on the top of the module interface board onto one of the black wire solder points. In my case its the brown wire.

5Volt from the veroboard solders is soldered onto the left hand side red wire on the main board. In my case its the red wire.Note don't solder to the bottom right red wire as thats the reset pin.

Next is the MISO (SPI Bus Master Input/Slave Output) and MOSI (SPI Bus Master Output/Slave Input)

You could solder these onto the main board but I used the programming plug connection just because it was easier.

MISO from veroboard (T2in pin 10 of MAX232 IC) is soldered onto the bottom right communication port pin. In my case its the green wire.

MOSI from the veroboard (R2out pin 9 of MAX232 IC) is soldered onto the top middle pin of the communication port pin. In my case its the yellow wire.

This wire needs to be cut somewhere between the veroboard and the communication port and a 470 Ohm resister solder and heat shrunk.

Thats it of the 9XR differences.

Follow Mike Blandford guide on the DJT mod and processor mod

Outline of Mike Blandford guide on the DJT modInternal to the DJT module, resistor R1 allows a PC to be connected to the external four pin connector. The PC serial output will override the 9X signal, but both the PC and the 9X will receive the data sent by the DJT module. A picture of my wiring inside the DJT module is shown in Figure 2. The resistor from the Rxd pin has sleeving over the bare wire to ensure it does not short to anything else. The wire from the Txd pin is kynar, a single strand insulated wire. Stranded wire is not advisable as it is very easy to allow a strand to short to an adjacent pin. At the four pin, external connector the wires are wrapped round the pin close to the circuit board and then soldered. These pins a sufficiently long that a mating connector will still fit when the wires have been soldered in place.

At the other end the wires are soldered to the pads by the pins. I did not use the hole, and made sure there were no shorts to the holes. Using a fine tipped soldering iron these wires were soldered without removing the board from the plastic case. Care needs to be taken not to melt the case with the iron. It is a very small space due to the daughter board with the switches and LED sticking up.

Outline of Mike Blandford guide on the processor board mod. This was modified as described in http://code.google.com/p/gruvin9x/wiki/FrskyInterfacing with two, surface mount resistors being removed to allow the serial connections to be made to the ATMEGA64A, and two currently unused pins wired via 220 ohm resistors to to replace the signals disconnected by removing the resistors, see Figure 4. Not shown is resistor R2 on the circuit. This is wired in-line on the white wire from the servo connector the the processor board. This resistor allows programming operations to take place with the serial interface still connected.

Note:I chose not to add the extra 220 Ohm resistors but instead us the SMD (surface mount resistors) already on the main board see http://openrcforums.com/wiki/index.php/9x_Full_Mod_Telemetry

Method 2 describes cutting the tracks between the resistors and the processor and using the SMD resistors (don't need to fit 220 Ohm ¼ watt resistors).

You could also tombstone the SMD but this requires unsoldered the SMD's and soldering one end to the board and the wire to the other end.

Hardware mods done.

If you haven't already flashed the new firmware onto the 9XR do it now.

Receiver turned off, no data Receiver on, receiver battery voltage