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Ardupilot Flight Controller with on-chip OSD

Posted by Andy Little on February 20, 2016 at 3:58pm

Since my main interest is FPV, and I use an OSD, I was interested originally to make  a vector graphics replacement for MinimOSD. Here is the original diydrones discussion .  Though that worked well, I next decided to incorporate the Ardupilot code into the OSD so it is all integrated on the same IC.   The software and hardware is all Open Source. The Project is also different in using FreeRTOS rather than Nuttx or Posix  The source code is available on github

Above is the initial version. 

Currently I am designing a dedicated OSHW board for the project

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Comments

  • Developer
    Andy Little February 23, 2016 at 5:48am

    @Thomas ,

    FreeRTOS is used on all the OpenPilot-derivative systems, and OP specialise in Copters pretty much.

    FreeRTOS is by nature designed to be good at this very purpose. Has mature sync mechanisms between threads and between thread and interrupts.  Stm32 ArmCortex M4 has extensive tiered interrupts and DMA with configurable priority which make the job easy too. STM32 and FreeRTOS is a natural fit. In fact FreeRTOS is used in mbed RTOS I believe and CMSIS RTOS in stm32 by default. http://www.st.com/st-web-ui/static/active/en/resource/technical/doc... It has a great pedigree

    regards

    Andy

  • Thomas Butler February 23, 2016 at 3:46am

    @Andy, 

    I ask about the Copter code to see how well the code with FreeRTOS runs on a multirotor which would be more mission critical since the motors stabilize the multirotor.  Any OS related glitches should/might manifest themselves better than in a plane.

  • Developer
    Andy Little February 23, 2016 at 2:12am

    Thanks for all the comments.

    @James

    I too am looking forward to sorting out the board :) I am currently planning a nominal 36mm x 36mm form factor with the standard mount holes spacing which seems to have evolved as the small board form factor of choice. Looking at Pixracer for connector tech and, if possible, I want to get some standard 0.1 inch pitch servo outputs on it , since the micro connectors cant carry current and so are a hassle for servos . In fact will take a close look at pixracer and try to model on that as far as possible

    @Thomas

    I havent tried building the code with Copter yet. I dont foresee any particular problems however.

    regards

    Andy

  • Thomas Butler February 21, 2016 at 4:38pm

    Hey @Andy, have you tried a build of ArduCopter in a multirotor? I'm interested in how well it runs under FreeRTOS.

  • Developer
    Andy Little February 21, 2016 at 10:01am

    @Digital Wings

       Thanks!

  • Developer
    Andy Little February 21, 2016 at 9:59am

    @ Andrew
       It will be my pleasure. I shall certainly be looking to put some of your code on it :)

    @Rana
       Thanks ! :)

    @Robert
       Hope to get it out there at some stage soon :)

    @Hein
       The ArduPilot flight code and the OSD drawing code run on the same mcu (stm32) in separate threads under FreeRTOS

  • Digital Wings February 21, 2016 at 9:52am
    Nice job!
  • robert bouwens February 21, 2016 at 12:11am

    now to buy this fc...

  • 100KM
    Hein du Plessis February 20, 2016 at 10:22pm
    Great work, can you explain "incorporating the Ardupilot code into the OSD"? Do you mean Mavlink?
  • Rana February 20, 2016 at 9:43pm

    Excellent work !

This reply was deleted.