Newbie here. 


Just purchased a ready-to-fly 3DR Hexa-C and installed drivers, downloaded and installed MissionPlanner-1.2.48 software.  Followed instructions to uploaded 2.9.1b firmware first before even thinking of selecting Connect button. 

Oh ya, I also verified correct Com Port, and bits per sec (115200) for both the com port and mission Planner.  The problem I see at or near the end of Read Hex File is a alert window "Communication Error-No Connection". 

At this point I have swapped USB cables 3x, uninstalled and installed  MissionPlanner-1.2.46, even uninstalled USB driver "Arduino Mega 2560" and installed arduino-1.0.4's driver.

Lastly, I opened the Mission Planner software and selected "Terminal" I observed "com port open" but was not able to send commands to module.

This was test on both my laptops (one I'm typing on is a Windows 7 laptop, the other was my Windows 8 laptop with driver signatures turned off.


What in the world am I doing wrong!  This should be this difficult.  Help!


Doug W.

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  • I know it this a late answer ... After I unplug my telemetry the problem went away.

  • Great tip. Its now 2015 and I brought back to life an old APM 2.0 by disabling the other ports.  Very retro:)

    • LOL. Glad this post is of help.  Happy flying!

  • I know that this was a while ago but it was a huge help.  Hopefully it is posted elsewhere.

  • Thanks. I had the same problem but I followed your instruction and it worked now.  

  • MR60

    I posted an identical issue for my one year old APM2.5.

    My conclusion is that APM2.5 is broken. Probable reason?: not sure but most probably APM2.5 is not very well protected electrically wise against the slightest voltage spike or connection error.

    I just hope Pixhawk shall last more than a year of use...

  • I just ordered a usbtinyisp programmer, to reprogram my ardupilot mega 2.6, where do i connect

    it on the ardupilot, and which bootloader do i flash ?

  • I found this article

    Sorry if this is a duplicate post of someone elses  -  kind of bleary eyed after solving this issue. Just wanted to notify people in case this is a  3D Robotics production programming issue that customers might find later on.

    First a question so not to get lost in my description of the problem. Is the bootloader for Ardupilot identical to the Arduino bootloader ? or is a custom bootloader needed ?

    I received a Ardupilot 2.5+ last week to upgrade my XAircraft X650 v8 frame. Because of the XAircraft ESCs, I need to modify the PWM software of the Ardupilot.  I went to install freshly compiled software and it failed to install - both with Mission Planner and with Arduino IDE. Thus being an absolute Arduino noob, the start of an all-nighter debug session.

    In a nutshell, the Mega2560 Lock Bit "BLB1" was set in the factory to "LPM_SPM_DISABLE". This prevented firmware upgrades.

    Fortunately, I anticipated that I would eventually corrupt the bootloader and ordered a Pololu USB AVR programmer. After installing AVR Studio 6, wrestling with it's major quirks, connecting to the incorrect ISP pins (I soldered on a 6 pin connector for the "other" on board CPU), fortunately figuring out the correct ISP is disguised with the accessory servo pins, I could read the fuses and lock bits settings.

    After erasing the flash memory, I could now modify the BLB1 lock bit and reinstall the bootloader via AVR Studio 6, and then use Mission Planner to upload "custom firmware". I used the Arduino 1.

    Arduino-1.0.3\hardware\arduino\bootloaders\stk500v2\stk500boot_v2_mega2560.hex bootloader. Seems to function correctly - will know shortly after putting the APM back together. But first......

    Off to desoldering the 6 pins I placed thinking the empty pad was the ISP connector. The APM cover won't fit with those newly added pins.

    Oh heck, I will mention one other possible production issue. The red-wire on the UBlox GPS to APM cable seems to be reversed. Doesn't affect operation, since the connectors are keyed, but IMHO a wee bit strange seeing the red wire aligned up with the ground pin.

    Thanks for any information on the bootloader.

    Sorry for my ramblings. Cheers

  • Did an upload firmware via Arduino and have a connection timeout issue. Is anyone can help me ? :(

  • Hi,

    I have exactly the same trouble and I'm unable to upgrade. Disable all COM ports, BT controllers... nothing works ... :(

    Is anyone can give me a workaround to upgrade it ?

    Thanks !

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