Adding a Transmitter Module to a Spectrum DX6i Radio and Mode change

Started by sundaram, January 27, 2016, 12:15:18 PM

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sundaram

Creating a DX6i Module hack log to share my experience and issues faced in the modification and solution to it in the process with the Fora.

Recently a Local Chandigarh Kid who had bought a not working second hand Spectrum DX6i got it to me for checking it and for reviving if at all it was possible. The radio was really bashed up and with three to four toggle switches broken, Antenna broken. The kid was very hopeful and said the radio switches on if powered up with four AA's and all the functions are navigating in menu.

I was more worried now since if he had powered up the radio with a broken antenna there was a very strong likelihood that he would have fried the tx module. Though I was very confident ( Not realizing at this stage the complexity of a Spectrum DX6i and its PPM output ) that an external module can be added. Took the radio from the kid as a help to a fellow aero-modeler buddy and as a modification challenge.

Opened the radio and was in for more shockers now. The Tx module itself was missing. The kid and the previous seller were clueless about its whereabouts since the radio had changed a few hands in damaged condition before reaching this kid. The radio was also mode 1 and some had earlier attempted to change the mode to Mode 2. So the ratchet and spring was as per mode 2 requirement but the software it was still mode 1. Since there was no tx module, powering it was not an issue any more so decided to change the mode to Mode 2

Changing the mode was not difficult followed the instruction at the attached addendum to the manual attached.
http://www.horizonhobby.com/pdf/SPM6630-Manual_Addendum_Mode_Change_EN.pdf

Instructions are very easy to follow.
Quote
Transmitter Mode Conversion
You can change transmitter modes between Mode 1 and Mode 2. This conversion requires both a
programming and a mechanical change.
Programming set up:
1. Power on the transmitter.
2. Press the roller, scroll to Setup List and press the roller to access the Setup List.
3. Select Copy/Reset in the Setup List. When the Copy/Reset menu screen opens, select Reset.
4. Move the Aileron D/R switch forward and backward FOUR TIMES. A screen will display Mode 1 and Mode 2.
5. Select the desired mode.
6. After you change the transmitter Mode in the Setup List, you will need to make
mechanical changes to the transmitter gimbals.
CAUTION: Always power off the transmitter and remove the batteries before


The mode change done in few mins and the ratchet and spring tension verified.

The Spectrum is powered with four AA's so at full charge its operating volts is 6Volts. Decided to add a OrangeRX DSMX/DSM2 Compatible 2.4GHz DIY Transmitter Module to keep it still as DSM mode radio. http://www.hobbyking.com/hobbyking/store/__40205__OrangeRX_DSMX_DSM2_Compatible_2_4GHz_DIY_Transmitter_Module.html.


Specs of the module was as under
Compatibility: Any transmitter with a PPM signal output
2.4Ghz protocol: DSMX/DSM2
Voltage input: 6~15VDC
Power: 100mW
Range: Full range system
4 operating modes: DSM2 comp. 1024/22ms, DSM2 comp. 2048/11ms, DSMX comp. 22ms, DSMX comp. 11ms

Since a discharged voltage of four AA's will be less than a 6 Volts decided to power the entire setup with a 6Volts BEC.

Ordered the tx module, four toggle switches required, 6 Volts BEC, and a Master power Switch to isolate the lipo from BEC when not in use.

sundaram

Installed a Turnigy Low RF BEC set to 6Volts. Removed all AA's battery clips in the battery compartment and connected a 2 S Lipo in the space through a micro JST. Powered it up through a master switch which isolates the Lipo from BEC when not in use. Removed the charging socket and installed the master switch in its place now since the battery cannot be charged in conventional method.

The output of the BEC 6 volts was now connected to the power plug of the radio where the battery box was connected earlier.




The relevant pin-out of the RF deck where the original tx module sits is marked on the image above. Irony was that DX6i does not output PPM like a conventional radio to the tx module from the RF deck. The PPM is at a different voltage levels to what is required for a standard tx module. further more it does not output PPM without the original TX module in place.

So the Orange Tx module was not recognizing any PPM from the RF deck when tapped from there.

For sometime I even thought the Orange TX module was faulty before studying various forums and realizing the above. Powered through a Frsky CPPM receiver output, BEC the Orange tx module was working perfectly as a relay radio in DSM mode with a Futaba radio. 

sundaram

I connected a simulator cable to the trainer port and connected a USB Simulator dongle to the PC and the radio was giving a functional PPM output at the trainer port and the simulator was working alright. Various forums were replete with details of addition of external tx module through trainer port.

DX6i powers up itself when a trainer port 3.5 pin is inserted in the trainer port. Battery rail is connected to a different power rail and it ouputs only PPM at the trainer port.
Battery box is directly connected to a different power rail and only the radio control circuit is powered on and the logic circuit allows PPM only to the trainer port.
There is no need to switch on the master toggle.
When powered through trainer port the internal tx module is switched off at the RF Deck.
If the master toggle is switched on with trainer port enabled logic circuit disabled the PPM output at the trainer port.

Decided to power the Orange Tx module through the trainer port and taped the PPM through the trainer port.
Added a toggle switch to power on the trainer port as if when a trainer port is enable when a plug is inserted.
Tapped PPM output and 6 volts output to the Orange tx module from the trainer port.



sundaram

Earlier when I tried to power the entire radio directly without a toggle switch, through the trainer port to enable PPM as well as functions without connecting the power to the main power connector at the main board, the Radio was not saving the settings at all and it was always resenting to the default setting.

The radio needs 6 volts power at the main board battery connector to save the last settings when switching off.

So you need to power up the main battery connector at the main board or power the parallel connections at the trainer port which are marked PWR and GRND while enabling the PPM output of trainer port.

sundaram

Placement of the orange tx module, status indicator LED and Bind push button is as indicated below.


sundaram

Now only the master power toggle can be switched on to change and save settings of the radio without switching on the tx module and with the second toggle the entire radio and tx module can be switched on (taking care without switching on the master toggle to prevent PPM fail at the trainer port)

The radio is now perfectly working on all modes of DSM and binding and functioning well with respective receivers.

Features of Orange Tx Module as under

Features:
• 4 operating modes: DSM2 comp. 1024/22ms, DSM2 comp. 2048/11ms, DSMX comp. 22ms, DSMX comp. 11ms
• Easy to access bind button
• Range check mode

Includes:
OrangeRX DSMX/DSM2 compatible 2.4Ghz DIY transmitter module
2.4Ghz antenna
Antenna extension cable

Module uses a unique Global ID for binding. In case of binding issues with other branded receivers press the "Change ID" button on module to change the Module ID to another unique value reserved for that module (5 ID's assigned to each module).

There are over 4 billion unique ID's assigned to OrangeRx modules.

rastsaurabh


sundaram


rastsaurabh


sundaram


rastsaurabh

To trainer port or inside...meaning plug and play or tweaking required.

sundaram

Both ways it can be incorporated. Thorough trainer port just three taps is required at the Futaba Square port.

incorporating an internal module can also be easily incorporated with just three taps in the the circuit boards. You can even add a three position toggle switch to switch between internal Fasst Module the DSM module or both switched off as per the requirement.

Its lot easier to incorporate on a Futaba.

You can follow this thread and it can be incorporated in similar manner. http://www.rcindia.org/radios-and-receivers/modifying-rc-transmitter-into-a-dual-band-900-mhz-micro-rc-transmitter/

Read PCM as CPPM please.

Hitesh jangir

Hii I am facing same problem I my drx orange rx 6ch transmitter it's tx module is damaged and I don't able find it's tx module so please help me. Please send the buying link at