How to modify your 9x to the DSM protocol
Hopefully by now you have enjoyed playing around with ER9x a little and you have come to a point where you want to expand the possibilities of your radio.
Or you have just gotten your 9x type radio, and you want to take advantage of the dsm protocol logic found in the ER9x firmware.
You want to use these!!!!
Either way, you have found the spot where we will show you how to take a module out of a DX4E and the 'toy' transmitter that accompanies many of the parkzone ultra micro planes.
DX4E will give you DSMX , Model Match and is a full range transmitter. Using the module from an HP6DSM radio will also give you model match, but no DSMX support.
The LP4dsm module found in this radio is limited in use, perfect for parkflying and bnf models
Tools and things you need
Before you start , as with anything electronic, you MUST MAKE SURE YOU ARE GROUNDED! Use a static discharge wrist strap, static mat, make sure you ground yourself Before attempting any electronic mods. Static Kills Components.
For the following guide, the following tools are required to complete the removal and installation of either module.
- Phillips #1 screwdriver
- Soldering Iron (appropriate wattage for electronic work)
- Solder braid or any other method of removing solder from a pcb board
- Wire snips
- Heat shrink wrap
- Hot glue gun
- Velcro or double sided tape
The following is a list of components required to complete installations
DX4e Module installation:
- 4k7 Resistor
- Diode 1n4001 ( Radio Shack Catalog #: 276-1101 )
- 24 or 32gauge wire (Which ever you prefer to use)
- Either a 3.3v Ubec or a voltage regulator (Level shifter circuitry)
- (this is needed to supply HP moduels a seperate power source.
- If you skip this, you will experience brownouts and your transmitter will constantly reset)
LP4dsm - Toy Transmitter
- Diode 1n4001 ( Radio Shack Catalog #: 276-1101 )
- 24 or 32 gauge wire (Which ever you prefer to use)
First remove the four screws from the back of the radio.
Remove the back cover, revealing the inside of the radio.
Next remove the five screws holding the mother board in.
Once complete, carefully remove the board.
You now see the location of the transmitter module.
This is how the hp6dsm transmitter looks inside. This is the tx that came with the Blade Sr.
Now, with a nice hot soldering iron (or gun)and your solder wick, remove the solder from pins on the module and gently pry it off. If it doesn't come off right away, try heating the pins again with the solder wick, and pry again. It will come off.
Once you are finished, you'll have a nice little module that you can now install into your radio.
This is the module from the hp6dsm, you don't need to de-solder anything, just unplug it.
- If you are looking for a Regulator to use in this mod, these are the locations for the DX4E and HP6DSM transmitters.
Left image DX4e regulator location, right image HP6DSM regulator location.
Remove the screws on the back.
Remove the screws holding the circut board in.
You will see only 3 pins hold in the module.
Using the solder wick, remove the solder and pry the board off carefully.
Now you have a module to place inside your radio and have some DSM compatibility.
- In case you want to use a regulator, this is the location.
The module from the DX4e only uses 3 pins out of the 12. Pins 1,2 and 6. All the rest are important, but not needed for this mod to work.
Some people have cut the unwanted pins, others have used printed pcb board, whichever method you choose, it will use the same parts, and same pins. I opted to just solder right onto the available pins.
Ground is Pin 1, 3.3 V is pin 2 and pin 6 is your PPM signal pin.
Picture on left is a DX4e module, picture on right is a module from a HP6DSM radio.
For the high powered modules, or full range modules you do require a reliable 3.3v source. I used a 3.3v 3amp ubec I picked up from hobby king. It was a quick cheap solution and I have a few laying around. (if you try to use the 3.3 on the main pcb, you will experience brownouts, all HP modules require a good reliable source of power, take it from the battery source)
Another method is to use a voltage regulator, you can canabalize one from the donor transmitter and install it into your radio without issue.
This is the circuit diagram I used to power the HP module. You can use it too for the LP module. Instead of a voltage regulator, I used a ubec.
Before you solder, tin everything. Tinning puts a small amount of solder on the points to which you want to solder. tinning also helps in cleaning the surface and makes it easier to attach components in awkward positions.
Once you've tinned your components and pins, take the 4k7 resistor and the ubec red wire from the output. (it's the thinner of the two reds, usually, just make sure it's from the out put of the ubec) and fasten them (solder) to pin 2 of the module. (pin 1 has a square around it)
Make the ppm wire now. Solder the diode and a length of wire together.(6 inches, you can always cut it down, it's a pain to make it longer, solder the length of wire on the stripe side of the diode, this will make the stripe furthest from the board when we attach it in the next step)
Once that's done, take the other end of the 4k7 resistor and the ppm signal wire you just made, and solder both to pin 6. (again, ensure you have the stripe of the diode furthest from the module)
*this module had its pin on the other side, just make sure you use pins 1,2 and 6 only*
At this point you can put heat shrink on where you want to cover the diode.
You now have a DMS2 module ready to install into your radio.
Lp4 is the same setup as the schematic above. Place a diode on the ppm signal (stripe away from the board), solder a wire to the diode to attach to the ppm on the tranmitter. solder a wire on the - and + (ground and vcc), pullup resistor between vcc and signal and you're done with the lp4.
If you want to use a voltage regulator , this is where it is located on the lp4 donor radio.,
Open up your 9x radio.
With either module, the ppm signal can be sourced here.
The full range modules (from dx4e,dx5e, hp6dsm or dx6) need to get their power from a stable source. (otherwise your radio will constantly brownout. Brownout looks like your radio is resetting, you watch your voltage go up to max, then, RESET, over and over again)
You can either hook it to battery source (if you use a ubec) or the 5.5v source if you use a voltage regulator. Ground is the centre pin Either way , you will need to supply the proper power the HP module needs to function properly. (For those of you who who need more guidance, if your radio browns out using the 5.5 supply, then use the battery source. As long as you use a regulator or a ubec, you should have no problem)
Pic/description of where lp4dsm gets its power***
You can ground the module in the same manner as the HP module, centre pin in above picture. Or any common ground in the radio.
Now that you've installed the module, you can fasten it inside.
The final step is the antenna. You can leave the stock module in the unit and use both. Some opted to use a switch and connect the ppm and power to it, so one module works at a time. I have removed the old module and placed the DSM antenna in place of the stock radio antenna.
Setting the proper protocol
Turn on your radio now.
From your main screen, long press right to get the modle menu
Press right until you get to the second screen of model setup, scroll down to protocol, press menu, then right or left to select lp4/lp5, dsm, dsm2 or dsm/dsmx. Press exit, now your in dsm mode.
Now, turn off your splash screen if you haven't done so already. Select a model you want to bind an rx to.
You must change models for every rx you want to bind. This is how model match works. Does not work with LP modules. (there are reports that some lp modules do support model match)
Turn off your transmitter. Get the rx you wish to bind ready. Turn it on in bind mode.
While holding the trainer switch, turn on your radio. This begins the bind process.
If your rx supports failsafe, you can set that up too.
Release the trainer switch, and watch the rx light become solid, it is now successfully bound.
Do this with any model you wish, but make sure you choose the model you want the rx to bind to first if you want model match to work. (there are reports that some lp modules do support model match)
With any of the modules listed above, you get 6 channels of control. Modules from a DX4e are the same as the DX5. Reports from other users who have used 12ch tx modules do get the full 12ch. I personally haven't tried it, nor have I seen it work.
<eof> WORK IN PROGRESS