Having trouble connecting your FC to a computer, or flashing FC firmware? Very often it’s an issue with flight controller driver. This tutorial hopefully can help you fix it in a few simple steps.
Errors when flashing FC firmware
Often when there is a driver issue with the flight controller in Windows, you might get errors when press the button “Flash Firmware”. One common error is:
Failed to open serial port
Then the FC COM disappears, and it appears again when you unplug the FC and plug it back in… The same problem keeps happening when you try to flash the FC.
The first thing you should do is to try a different USB cable. Sometimes an USB cable might be designed for charging and not for data connection, or the cable is simply damaged.
Or you might be getting this error:
No response from bootloader, programming failed
If you are able to connect your flight controller to Betaflight GUI, but you just cannot flash firmware. In which case please follow these steps to resolve the problem.
If you cannot connect to GUI at all, please try the “bootloader fix” first to flash the firmware. If that doesn’t help then read on.
Try restarting your computer and repeat the above before moving on.
2 Types of Flight Controller Driver Issues
There are two types of flight controllers by the way they connect to a computer:
You can find out whether your FC is the CP2102 or VCP in order to choose the suitable solution to fix your driver issue.
VCP Boards: ImpulseRC Driver Tool
Connect your FC to the computer with USB cable.
Download and run ImpulseRC Driver Fixer Tool (it’s a 3rd party software, please scan with AV software before running it)
This tool will automatically search for your FC, and install whatever driver you need on your computer.
Once that’s completed successfully, the driver should be installed. Now fire up Betaflight Chrome App GUI, and you should see “DFU” next to the connect button, rather than the usual COM port in the text box.
You should now be able to flash the FC as you normally would.
Once done, your COM port will reappear in the text box. And you should be able to flash the FC from now on without any issues on this computer.
CP2102 Driver Fix
If you have a flight controller with CP2102, you need to install the CP2102 driver.
Note that with SPRF3 boards, you might want to try changing the baud rate to 256000 first, maybe that would do the trick.
First of all, connect your FC to the computer via USB. Without proper driver it’s difficult to tell where it is in Device Manager. The easiest thing to do is to use Zadigto find it.
You can download both the CP2102 and Zadig drivers on the front page of the Betaflight Configurator.
Run Zadig, choose your flight controller in the drop down list (1). There are going to be many options but choose the one that is more likely to be your FC.
After the green arrow select WinUSB (2), and press replace driver (3).
After that you should find the “CP2102 USB to UART Bridge Controller” under “Universal Serial Bus devices”. The one that isn’t greyed out. Right click on it and click Update Driver Software.
Select the driver you want to install, Silicon Labs, CP210x USB to UART Bridge.
And that’s it, the COM port of your FC should now appear in the FC configurator.
I am having problem flashing the board, I’ve tried everything, and DFU is displayed in GUI COM port, but it’s just not flashing and i get the following message:
Read protection not active. USB device successfully closed
Try to un-select “Full chip erase” option before flashing, and you could “erase settings” in CLI after the firmware flashing. Type “Default” in CLI to reset all settings.
- Jul 2017 – Article created
- Aug 2017 – added fix for CP2102 missing driver