Build your own DSM2 transmitter module (its working!) - Page 28 - RC Groups
Shop our Airplanes Products Drone Products Sales
Thread Tools
Jan 30, 2012, 07:07 PM
I don't want to "Switch Now"
pmackenzie's Avatar
Originally Posted by GolfFear
i need help for my tx.....
why it dosn't work? hmpf

any idea ?
Didn't you mention getting a scope to look at your PPM signals?
Sign up now
to remove ads between posts
Jan 30, 2012, 09:22 PM
Registered User
i self don't have a scope and knows nobody that it have.
but i want to try it with the soundcard on my notebook today
Feb 01, 2012, 08:58 PM
Inciting Riots
village_idiot's Avatar
Now that I have one of these in my hands I can see how different they are from the rf board in the DM8 module.
Feb 02, 2012, 12:25 AM
Yes, "that" Karl...
karl k's Avatar
I'm getting erratic behaviour with my module used in my Aurora 9.

Do I need to add a circuit to limit the PPM pulses to 3.3v?
Feb 02, 2012, 10:30 AM
Registered User
I have a strange behaviour. I built 3 converters. One for a FF7 with a DX5e module pulled from a DX4e. Working perfect. Then I built another two, same circuit. One with the small 1mW module, working also fine with a FF9 radio. And then I have my nemesis.

Built the same like the others, a DX5e module from a new V2 mcpx DX4e. I tried everything. checked the code. Checked the serial signal to the RF module. Built a serial interface with a Prolific chip, which is capable of 128kbit (reading the same data like when the module is connected to the DX4e back). When I try to bind, the RX changes flashing, and stops flashing. But afterwards the light does not get solid. If I plug the module to the DX4e back, everything works fine (I soldered a connector for testing on it).

The only difference I found so far is the time between 2 frames. With the DX4e it is about 21ms, with the arduino and T10CP I get 23ms. Can this be the problem ? The impulses of the serial communication are the same length, so the bitrate should be fine.
Feb 02, 2012, 06:49 PM
I don't want to "Switch Now"
pmackenzie's Avatar
Are you binding to the MCPx?
It is fussy about the timing being too long, but will work with anything below 22msec, right down to 11msec.

Best time to use is 22msec. Works with everything I tried(AR61xx,AR7000,AR8000,MCPx, DSMx mode where applicable)
(This is the total time for the frame including the data packet, not the time from the end of the data packet to the beginning of the next one)

Pat MacKenzie
Feb 03, 2012, 03:19 AM
Registered User
I tried binding to a 6100, 6210, I will try an AR8000 today. It seems the frames come with a time of 23ms out of the futaba. Contrary, if I use my first built module, I can get it to bind.

I will take all the modules I built on Monday and compare them systematically.
Feb 03, 2012, 09:50 PM
Registered User
Hi All,

Need some help here.Want to get mode 4 on a DX6i which does not allow channel reassignment as far as the sticks go. Is there any way around this other than pulling the plugs on the main board and switching them. Another way would be to get a Turnigy 9 and stick a DSM2 module in it. Any other way?

Feb 03, 2012, 10:06 PM
I don't want to "Switch Now"
pmackenzie's Avatar
You might be able to do it from the service menus:

Pat MacKenzie
Feb 04, 2012, 08:47 PM
Registered User
Hey everyone,
I just found this thread yesterday, and I just wanted to say that you've done some awesome work here!

I have thought about controlling my new mSR X (and more advanced helis) with a computer, and you've finally got me on the right path!

Last night I whipped up a quick Android app that lets me see the values coming out of the controller. You guys made it really easy!

The next step for me is gutting my second controller (just snagged it for $15!) so I can talk to the module directly and fly the heli from my phone.

Here's a video of the app I made that reads the controller:
Blade Helicopter Controller to Android Phone (2 min 0 sec)

I read on another thread (I think) that there is a bit of a binding procedure when you're talking to the radio? I can find or figure it out myself, but if anyone knows what that is or has a link handy, I'd appreciate it.

I'll open source all my code when its a bit cleaner!

Feb 04, 2012, 09:20 PM
I don't want to "Switch Now"
pmackenzie's Avatar
There are two kinds of modules. Some of them go into bind mode every time the module is powered up. Those are simple to use
The other requires a slightly different header to enter bind mode. Generally those ones require you to push in a stick or something like that on power up to enter bind mode.
Bind mode can only be entered on power up, not later.

You should be able to modify your Android app to display the value of the first two header bytes. to see what is going on.

Can you describe the hardware+software you are using to go from serial into the USB port?


Pat MacKenzie
Feb 04, 2012, 09:34 PM
Team WarpSquad
Daryoon's Avatar
@tlalexander: That's pretty cool. Have you looked at these two pages?
Feb 04, 2012, 11:26 PM
Registered User
Thanks guys!

@Daryoon - I hadn't seen those pages. I'll look them over!

@pmackenzie - Yeah I'll have to change my app to grab the first header bytes. Right now it just keeps displaying the next packet it finds. I have the kind of transmitter that requires you to press down on the stick to enter bind mode, so I'll have to sort that out.

I do give some description of my setup in the video description (which you have to go to YouTube for, instead of watching the embedded one).

But basically, I have a 3.3v USB to serial board (FTDI type) I got from, and I have the RX and ground on that hooked up to the data and GND lines of the controller.

Then I wrote an app that uses an open source FTDI library for android to talk to the FTDI chip. Its all pretty simple actually.

I'm using the standard Android development environment (Eclipse) that they suggest you use (and is free).

See the youtube video for more links.
Feb 05, 2012, 09:33 AM
Registered User
Got it working! I can fly the heli with my phone now! (well, I can control all the channels... flying with a touchscreen is damn near impossible)

The binding array for my transmitter is:
0x80,0x00,0x00,0xAA,0x05,0xFF,0x09,0xFF,0x0D,0xFF, 0x13, 0x54, 0x14,0xAA

which appears to be a little different than others.

Anyway, I stayed up till 6:30AM to do it, so... I'm gonna go to bed now.

More details later.

Feb 05, 2012, 01:21 PM
I don't want to "Switch Now"
pmackenzie's Avatar

You can send the channel data after the header bytes during binding
It is used in some receivers to set power on positions and failsafes, and with the MCPx it is used to set the operating mode.

Pat MacKenzie

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Anybody ever ask you "Why don't you build your own planes?" juantrinidad Electric Plane Talk 21 Feb 26, 2003 10:34 PM
FS: Build your Own Lithium Packs Cheap jcherry Aircraft - Electric - Airplanes (FS/W) 0 Dec 15, 2002 09:01 AM
What's A Good Program To Build Your Own Website For A Begginer? Joe Elston Life, The Universe, and Politics 12 Oct 16, 2002 05:29 AM
Sites on how to build your own batt ZAPPER Kevin Graehl Batteries and Chargers 28 Aug 29, 2002 02:53 AM
Build Your Own Defense Budget coastalflyer Life, The Universe, and Politics 6 Jun 02, 2002 04:12 AM