Electronic upgrades Multicopter

Telemetry mod for DJI Phantom 1

After my Y6-Copter with APM, I also want to see telemetry data of the Phantom 1, which isn’t capable on its own to transmit any data.

The original PPM receiver (Single antenna) got swapped by a FrSky XRS, which is amazingly small and has PPM, S.Bus and S.Port.

The translation between Naza-GPS and S.Port is done by an arduino nano which is connected to FrSky-S.Bus on Pin9 and to GPS Tx on Rx (also power from the receiver cable).
I used the software by Alezz in this thread but had to make some changes to get it running. My changed version is online at GitHub.

Here are some Pictures of the harness with the arduino and the Installation in the Phantom 1.


I didn’t want to cut the GPS connector, so I just pushed a jumper wire in the connector.
That was initially just for testing but made such a solid connection that this will stay in there.


The GPS Format in Degrees+Minutes formatted as DDMM.MMMM.
So 1234.5678 means 12°34.567′

I still have some trouble with the GPS coordinates, sometimes just the Longitude will be transmitted and Latitude is just 000 but this will be updated as soon as I get further.
Also I’m a little confused about the “Alt” “Galt” and the “Alt” on the GPS screen. They all differ, but I will observe that during flight and remove the ones I won’t need from the arduino code.

Electronic upgrades Multicopter

Telemetry mod for APM and FrSyk X-Series (X4r)

After the Telemetry mod of the Turnigy 9x, the air-side has to be able to communicate, too.

Because the APM is not able to speak the FrSky-Protocol itself, a converter is needed to translate the data. There are several projects out there, mostly using a teensy. I decided to use rotcehdnih’s version, which is also cabable of running on an arduino nano or micro.

This is quite simple, just burn that softwre to an arduino (I’m going with an arduino pro micro), connect RX to the TX of the telemetry port and pin 9 to the S.Port of the FrSky receiver. Then just add some power (from the APM Telemetry port for example) and there you go!

Electronic upgrades Multicopter

Telemetry mod for the Turnigy 9x an FrSky XJT Module

Hey Guys,

today I modded my Turnigy 9x to be able to receive Telemetry date via the FrSky XJT module.
There are many Telemetry mods for the 9x out there but most of them for the DJT or DHT module which use a serial connection on the ground side. The XJT also has a S.Port wich is already connected to the internal 5-pin connector. This makes any modification to the module unnecessary.

Like on the serial mod, you have to free up the UART pins on the 9x processor which are used by the two lower rear switches. In the images you can see that I did already connect the ISP Pins for flashing new Firmware to the 9x. Then I cut the traces for the most left resistors and connected them to the unused pins 41 and 42.
The two freed pins (RX) and (TX) are again getting connected to the ISP pin. Pin 2 will also be our S.Port pin.


Important Note: Don’t do the mod like I did. Just desolder the two resistors and replace them with wired 120Ω one. So you don’t have to cut any traces and this makes soldering a lot easier.

Now we need to create a little circuit for inverting the S.Port signal (not quite sure if this is necessary, but it worked for me!):

  • schematics

The S.Port is connected to pin 5 of the internal connector between the 9x and the module. This pin is unused and connected to the large solderpad. (Don’t know what it was supposed to be). I just connected the signal cable to the large solder pad.


Now the inverter PCB hast to be connected to the processor. Signal to MOSI, power to 5V and GND to GND:


I also wrapped the PCB in duct tape to insulate it.


That’s the hardware side.

I used the er9x Firmware in the FrSky version wich uses the changed switch pins and enables telemetry. You can download the firmware and the flashing utility from the er9x webside. Remember to save / write down your settings before flashing.
To get the 9x to listen to S.Port instead of RX/TX, you have to set the protocol to PXX. Now you should already be able to see the RSSI values.

REMEMBER to rebind the receiver if you switched from another protocol to PPX.

CAN-BUS Car mediacenter Electronic upgrades

Music-Player gets CAN-BUS!

Lets’s get deeper in the car’s electronics

My XBMC-Mediacenter works pretty well. But the only way to skip a song is the I/R remote placed in my armrest and to see what song is playing, I need to switch the whole display to mediacenter mode.
Because I always wanted to take a closer look at the CAN-BUS in my opel astra, I decided to give the music player another update.

So I ordered a MCP2515 / MCP2551 CAN-BUS interface for a raspberry pi and started to scan the bus.

The opel astra h (2004-2010) has the following busses:

  • SW-CAN (SingleWire) 33.3 kbps also known as “GMLAN”
  • MS-CAN (MidSpeed) 95.0 kbps
  • HS-CAN (HighSpeed) 500 kbps

The car body bus

The first was to capture some “base noise” with the bus awake and the ignition off. Then I performed some actions like pressing buttons, locking/unlocking the car etc.
That capture could be compared to the base noise to identify the messages only send in that capture. That gave me some results:


This means that when I send 160#0340C803, followd by 160#0300C803, the car locks! This point was a huge milestone!

  • can_lock

The entertainment bus

What I really was interested on was the MS-CAN with the unusual 95 kbps!
So I did the same as above and found what I wanted:

206 # 01 91 00 - Steering Remote UP
206 # 01 92 00 - Steering Remote Down

I also found the outdoor temperature:

683 # 46 01 XX where the temp in celsius is XX/2-40 so 0x00 is -20.0°C and 0x76 is 19.0°C.

But the really cool data goes to the display:

6C1 # 10 2E C0 00 2B 03 01 01
6C1 # 21 00 20 23 03 00 41 00
6C1 # 22 75 00 78 10 0A 00 1B
6C1 # 23 00 5B 00 66 00 53 00
6C1 # 24 5F 00 67 00 6D 00 41
6C1 # 25 00 75 00 78 11 01 00
6C1 # 26 20 12 01 00 20 01 00

The first byte of the packet identifies a multi-packet message. It starts with 0x10, than follows 0x2X where X increments from 1 to F. So after 0x2F comes 0x20, 0x21…
The second Byte of the first packet is the number in Bytes. The last packet is always 8 Byte long but the rest is ignored (these are either filled with 0x00 or the same then the previous package).
Than are two byte of command or mode. This is 0x4000, 0xC000, 0x5000 or 0xA000. Don’t know what that means… Than comes the size and type of the following container. Type 0x03 seems to update the main screen.
Now follow some strings, starting with an ID (here 0x01,0x10,0x11 and 0x12), the number of characters and the characters in UTF-16 (where only very vew unicode-chars are supported but that comes in the next post).

That’s all…

This is a schematic view of the above packet:

  • CAN_schematic



With that knowledge, I generated my own packet:

6C1 # 10 54 C0 00 51 03 01 01 - 84 Bytes, mode 0xC000, 81 Bytes payload, type 0x03, id 0x01, 1 char
6C1 # 21 00 20 02 03 00 41 00 - Whitespace, id 0x02, A
6C1 # 22 75 00 78 10 07 00 48 - u x, mode 0x10, 7 chars, H
6C1 # 23 00 61 00 63 00 6B 00 - a, c, k
6C1 # 24 65 00 64 00 21 11 0C - e, d, !, id 0x11, 12 chars
6C1 # 25 00 76 00 69 00 73 00 - v, i, s
6C1 # 26 69 00 74 00 20 00 6A - i, t, Whitespace, j
6C1 # 27 00 62 00 30 00 2E 00 - b, 0, .
6C1 # 28 64 00 65 12 0C 00 68 - d, e, id 0x12, 12 chars, h
6C1 # 29 00 61 00 63 00 6B 00 - a, c, k
6C1 # 2A 61 00 64 00 61 00 79 - a, d, a, y
6C1 # 2B 00 2E 00 63 00 6F 00 - ., c. o
6C1 # 2C 6D 00 00 00 00 00 00 - m

And what happened? This:

  • 20150703_112814_HDR


Next: Fully working prototype

Electronic upgrades

External Antenna for Logitech G930 headset

My Logitech G930 is a very cool headset but sometimes has little connection problems.

The solution offered by logitech is to change the frequency but in my case the problems seams independent to the frequency.
I have some 2,4 Ghz antenna stuff from older WiFi projects lying around and decided to take a clother look to the transmitter.
What I found are two PCB-antennas and two coax test points, so i took a RP-SMA pigtail, connected it to one of the test points, cut the connection to the PCB-antenna and attached it on the casing:

  • IMG_20140331_135829
  • IMG_20140331_140523
  • IMG_20140331_135836
  • IMG_20140331_141100
  • IMG_20140331_143016

I can’t yet say if the connection problems are solved with this, but the range is significantly better with the antenna!

There was two antennas inside the transmitter and I have no idea if they are diversity or one sends and the other receives or what they are for.
But when I have another matching pigtail in hands, I will connect the other one too…

Electronic upgrades

Retrofit radio controlled clock

Last sunday, germany switches to the daylight saving time again, so i needed to adjust some clocks.

We had a weathers station with wireless temperature and humidity sensors that has a clock which needs to be adjusted manuall while most of that weather stations have radio controlled clocks integrated.
Even my very cheap weather receiver which i got from a giveway and was only used to analyze the wireless temperature signal has a time receiver.

So i wondered if it is possible to put the receiver from the cheap weather station in the one we are using. Quickly opened it and found four empty soldering pads labled “RCC” – maybe radio controlled clock or something like that. Also the four pads itself are labled:

GND – Ground
VDD – Voltage source (3V)
PON – Power on Signal (3V)
TCO – TimeCOntrol? At least a data pin..

The labeling matches with the sensor, so i simply connected it:

  • IMG_20140330_140224
  • IMG_20140330_140237
  • IMG_20140330_140904
  • IMG_20140330_140207
  • IMG_20140330_140216
  • IMG_20140330_141438

Near the connector are two soldering Jumpers (S1 and S2) which are explained on the PCB and must be switched from S1 to S2.
Also there are two empty component places, usually used for the receiver which doesn’t exist on the source PCB:

R16: Pull-down resistor for the PON signal. This is already implemented in the receiver module
C12: Filter capacitor for the data signal – maybe not needed.

So both stay empty.

The case has already mounts for the antenna where my antenna exactly fits in!

At least everything is put back together and six minutes later:

  • IMG_20140331_105247

The time is synced! And again one less clock to adjust!