Tuesday, May 12, 2015


Sparky2 is available here

In case you want the video first:

After the amount of fun I had putting a VTX on Brushed Sparky, it got me asking what else would benefit from integration? In the background, I've also been plodding away at a few various revisions of TauOSD. This was inspired by BrainFPV resurrecting and vastly improving the OSD code. The video overlay of that was working fairly nicely, so adding a VTX directly on board seemed like a fun idea.


  • Fully graphical OSD with crisp black and white OSD and double buffering
  • Integrated 32ch 600mW 5.8ghz VTX. Channel selection provided via GCS.
  • Powered by STM32F4 with enough CPU power to redraw every frame
  • 5V and 12V switching supply that can be used for camera and external VTX. Nice clean power.
  • Switchable camera input (can be controlled via transmitter)
  • Runs up to 4S batteries.
  • Gets data from flight controller via CAN
  • Serial port available for mavlink telemetry (not implemented yet)
  • standard 36x36mm footprint
Back with 32ch module

This creates a really compact setup as you can stack a Sparky2 on top of this and have everything you need for flight, telemetry, OSD, and VTX in a 36x36 footprint (although I'd recommend a heatsink on the OSD). I still don't find an OSD incredibly useful, but the minimal set of things like altitude, battery, current and flight time really are quite useful.

Minimal hardware required for an OSD and FPV system. Sparky2 is powered from the TauOSD+VTX and sends all the information for the overlay.


I installed both Sparky2 and TauOSD+VTX in my havoc for testing. This is using the 12V supply to a PZ0420 board camera mounted on the front.

Here it is flying. This is running on a 4S battery directly into the OSD, which is then also powering Sparky2.

So far I'm quite happy with the video, which looks really crisp and clean. The OSD is stable and easy to read (thanks BrainFPV)!

The previous VTX used a TX5813 module followed by an HMC406MS8G. It was a learning experience to get all the video traces routed carefully at 50 ohm (working out for OSHpark specs), with components placed at various phases along the transmission line. I was happy to see it seems to work well, although I really could do with a VTX power monitor to see if it really hit the spec'd power.

The latest version uses a really nice 600mW 32ch module which is convenient for supporting all googgles.

Future plans

  • Sync the settings back and forth between Sparky2 and TauOSD to allow the awesome settings configuration menu that BrainFPV developed to be used.
  • Do more flight tests showing off features like video input switching.
  • Embed telemetry information in the audio stream


  1. Like that a lot. This will for perfectly with my Pixhawk setup. You could kill the minimosd and the its text osd. As for mavlink, ready to help on this.

  2. This might work really well with another idea I've been kicking around. I want to set the video channel I'm using not from the GCS, but from the transmitter. And not just for the VTX but also the VRX in parallel.

    What I'm envisioning is this.

    Transmitter: Taranis, because nothing else really has the flexibility. One 3 pos switch, One momentary switch. Two receivers (you can bind 2 at once on the Taranis). One channel on each receiver for video channel (32 positions).

    Switch UP - Channel "A" sent to both receivers (one in model for VTX, another at the video receiver to control them both together.

    Oh NO, someone jumped on your channel?!

    Switch Middle - Channel "B" sent to both receivers, poof you're on your "backup" channel.


    To store the A and B values would work like this.

    Switch UP for A, use momentary toggle to cycle through the channels. ONLY gets sent live to the video receiver so you can find an empty, clear channel. You don't want it to the vtx yet to avoid knocking other pilots out of the air.

    Switch Middle for B, same thing but for B.

    Switch Down - Save values.

    Switch returned to UP for A, now sent to both. Or mid for B, now sent to both.



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  4. Hi Peabody124,

    Has there been further developement on the TauOSD?
    And the whole Sparky CANBus Implementation which I find very interesting.

    One TauLabs Github there a 4 month old firmware but unfortunately none of the hardware files

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