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3D Robotics

ArduPilot MUX issue update: CKDIV8 fuse

Posted by Chris Anderson on February 6, 2009 at 11:29pm
We have now fully diagnosed the ArduPilot MUX firmware problem, and it turns out there were two problems, not one. The early boards were flashed with the wrong firmware, which was fixed on 1/26, but the boards after that until 2/5 continued to have a second problem, which is that the CKDIV8 fuse in the Attiny45 chip wasn't cleared at the factory, as it was supposed to be. What does the CKDIV8 fuse do? It divides the internal 8Mhz clock speed by 8, so the Attinys ship from the manufacturer with a default clock speed of 1Mhz. Our code, however, was designed to run at 8Mhz, so we clear that fuse to bring the chip up to its full speed. If you have an affected board, what should you do? Clear the fuse yourself with your AVR programmer and AVR Studio. Instructions are included in this post. Our apologies again for these teething problems, but I think this time we've squashed the last bug. All board shipping now have that fuse set correctly.
Tags: ardupilot
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Comments

  • Ayoub Zarzouri August 1, 2016 at 5:01am

    Please Guys I need help 

    I am working in Xplane with MP in order to SITL ,I followed all the steps in the manual but MP gives me this error below .

    What's the problem ? should I add something to my computer in order to get it done ??

    3691311371?profile=original

  • James Turner March 23, 2009 at 1:15pm
    Chris: Thanks, Thats good to know.
  • 3D Robotics
    Chris Anderson March 23, 2009 at 7:31am
    James: Every Rx handles loss of signal differently. It appears yours holds last state. It looks like your ArduPilot is working fine.
  • James Turner March 23, 2009 at 4:20am
    Please can someone tell me how I would tell if the board I received in early February is affected? The mux appears to switch okay except if I power off my transmitter then it's always stays in the last state before before powering off the TX and I'm sure it should switch to failsafe. could be my receiver though. Thanks, James
  • 3D Robotics
    Chris Anderson March 22, 2009 at 9:25pm
    Bill,

    I'm sorry to hear that--I thought we'd stamped out these production glitches. Just to be clear, the CKDIV8 fuse was set on your AT45? (It should have been cleared)
  • 3D Robotics
    Chris Anderson February 11, 2009 at 7:30am
    Reto, just a note that the schematic and PCB files are always on our home page in Eagle format
  • Simon February 11, 2009 at 3:23am
    Hi Reto
    It's well worth studying the Eagle layout and schematics to be found in the Ardupilot home page but maybe this will help :


    The block of ICSP connections for the ATmega168 are exactly the same arrangement but shifted to the left hand block.
  • Scott James February 11, 2009 at 2:01am
    Anyone in Australia have an AVR programmer and AVR Studio who could reset my CKDIV8 Fuse for me?
    Otherwise a new ArduPilot would be cheaper. Thanks!
This reply was deleted.