Air v1.2: Failed to enter command mode

I recently purchased a set of 915Mhz 3DR Radios from the store and am having trouble verifying the behavior of the 'air' module using a USB-to-TTL device.

The 'ground' module is v1.1 and the mission planner was able to load its settings correctly.

For the 'air' module the mission planner and the radio config tool yield an error message - "Failed to enter command mode", when I attempt to load the settings from the device. The green light stays solid for a second and then flashes steadily as soon as it is plugged in.

Any advice?

-Error Message-


-Port Settings-



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  • Developer

    Does that USB-TTL use a SiLabs chip?

  • 3D Robotics

    Maybe you've got your RX and TX wires reversed? (RX on one board should go to TX on the other, if memory serves). I'm not familiar with that particular USB-to-serial board. 

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