Bitcraze Forums

I bought a new CF2，and I flash crazyflie-firmware using radio，i'm sure the source code is right.

after flashing , CF2 still cannot fly and the two blue LEDs (2 and 3)are fully fit.when I connect to radio with crazyflie client. the four LEDs are all fully fit(1,2,3,4). why this problem happen?

It may happen that flashing fails, in that case you should just try again. If you cannot start the Crazyflie in bootloader mode (this can happen if flashing the nRF51 failed), you can always enter the bootloader by disconnecting the battery, pressing the button and connecting the battery while the button is pushed and finally releasing the button when the blue LED flashes.

If it still does not work I suggest you try flashing a release firmware to make sure the Crazyflie is working.