USB DSM2 Transmitter for my Blade MSR helicopter

Today i flew my Blade MSR using a joystick, my PC, and the 2.4ghz LP4DSM transmitter which used to be in the tx controller. The serial protocol is best documented here, but information on this exists elsewhere including here in a few posts, on diydrones. I'm pretty excited that I finally got this took a few nights of serious head scratching to work out some kinks.

I used a USB to TTL breakout board to transmit to the LP4DSM module, which apparently is a pretty common module found in numerous spektrum and other transmitters. I used LabVIEW to assemble all of the code, pulling axis information from the joystick, filtering this data, and converting that into hexadecimal PPM which was sent via serial to the TX.

I still have some bugs to work out, but it worked, and that is progress.

So, while I was working on this, I also bought an Arduino Pro Mini (yes, i gave into the temptation of a $20 already tested, super small, and assembled board :-D ) and an "ArduIMU Sensor Board - Six Degrees of Freedom (Main)". I put the board name in " " because it's actually only 4 degrees of freedom, having a 3 axis acc and a 1 axis gyro, with analog output.

It doesn't come with any documentation (nor does the Arduino Pro Mini), and I'm not sure if that is common or not. There is online documentation for the Arduino Pro Mini, which is helpful, but I find the information here on DIYdrones to be the best resource. thankfully the hardware is somewhat self explanatory.

Lastly, I bought two micro servo boards, which are the same servos on the Blade MSR, and the BMCX, and possibly others. i'll have to post the name/details of those servos later, i can't find the info right now.

My plan is to put both boards on my MSR, to make a stabilized camera mount using my endoscope vid camera. You can see where this is going.... :-D

....pull off the 5 in 1, add 2 more servos and a rx, and I should have a blade MSR that can be video camera flown, flight stabilized, and hopefully very, very cool. (and hopefully light enough!)

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  • I believe it will, but I am not exactly sure to be honest. I am still new to all of this.

    So to go along with your comment, I read somewhere that someone found that their MCX had 1 or 2 "hidden" channels that could be used to transmit data, but were not currently being used. I need to look through forums again, but i am hoping that I will be able to send all additional information including pan/tilt from my PC, using theses extra channels. From a quick check of the protocol, i do know that my tx module is transmitting a 5th and 6th channel, which my MSR does not use. So now I just need to find out how to pull it off the rx. I'll let you know if I find anything useful from this.
  • Thanks, that's interesting.
    Do you know whether the LP4DSM can bind to an AR6100 or AR6110 or just to the MSR's 5-in-1 ? I would like to use it to control a camera on my heli, i.e. pan, tilt, shutter. As the video is displayed on the computer anyway, it makes sense to have the camera control there as well.
  • okay, i found the link: i picked up two Spektrum 1.5g linear servos ( These include the servo drivers on the board, so that was a selling point along with the 1.5g part

    thanks for the links! i think i was hoping to find some data sheet or other consolidated source of info on this board. however the more i look at it, the more i realize it's pretty straight forward, and all i really need to know is contained on those pages.
  • The pro mini is quite well documented on the main Arduino site.

    Nice work!

    Oh, what's a micro servo board? Are you talking about a replacement for the electronics within the servo, or just new servos?
  • Nice, looking forward to getting a blade myself.
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