Are you having trouble connecting the flight controller with a broken USB port to Betaflight Configurator? Don’t throw away the FC just yet, you might be able to fix it. In this tutorial I will show you how.
The trick is to use an FTDI adapter, and hook it up to one of the UART on your FC. But there might be extra steps depending on the type of USB connection you have on the flight controller, i.e. CP2102 or VCP. This post explains how to tell which one you have.
Before you begin, check if you can solder the USB port back on. This may be the quickest solution, though it’s not an easy soldering job.
CP2102: Using an FTDI Adapter to Connect Flight Controller
If your FC has the CP2102 chip on it, you can just connect the FC to your computer using an FTDI adapter via UART1.
Connection: Only 4 wires are needed, TX to RX, RX to TX, 5V to 5V and GND to GND.
If this is the first time you use an FTDI adapter, you might also need to install a driver on your Windows PC. You can normally get the link to the driver file from the product page of your FTDI adapter, or simply google the type of adapter you have.
Then just hit the connect button in Betaflight Configurator. That’s it.
FTDI Adapter on the left, connected to UART1 of my FC on the right
VCP FC: You need to Flash Custom Firmware First
If your FC uses VCP for USB connection, it’s not so straight-forward. Because none of the hardware UART’s are enabled for USB communications by default.
What you need to do, is to flash a custom firmware that has UART1 enabled for MSP (USB connection), then you can use the FTDI adapter on UART 1. This is also useful when you have trouble connecting to the configurator through the USB port.
To find this custom firmware, first enable “Show unstable releases” in the firmware flasher in Betaflight Configurator. Then you should be able to select “Maintenance (USB Rescue)” as highlighted below.
You can flash firmware via UART1 using an FTDI adapter.
Last Resort
If none of these work, you can try cutting a USB cable, and solder the wires directly to the USB port solder pads on the FC. This way allows you to get into the configurator and enable USB connection on a UART.
Edit History
- May 2018 – article created
- Apr 2021 – Betaflight now offers USB Rescue firmware in the firmware flasher, you no longer need to download it manually from google drive
20 comments
Hello
I have tried it but i have a problem with the driver. I have install the driver for the FTDI adaptater so I can’t install the DFU at the same time. So it’s impossible to flash in usb rescue mode…
Hi! Is it possible to flash Kakute F4 V2 with Maintenance software via FTDI adapter, since UART 1 is dedicated to SmartPort telemetry and seems to only have one pad? My usb-port was ripped off.. Thanks!
Yea you should be able to flash it too.
So, should I solder both Rx and Tx of FTDI adapter to the same SmartPort (UART1) pad? Also, the documentation says that UART 1 is inverted, is that bad?
I accidentally cleared my uart 1 tx pad in cli. I didn’t know it was connected to the usb port. How do I access the FC now?
Re-flash firmware and reset settings, that’s the only way to fix it.
If pins D- and D+ are broken out like on the Matek f722-se, just cut and solder the white and green wires from a usb cable to those pins and power the device. There is one magic trick and that is to bridge pins 4&5 on the broken usb pads. This will set the “mode” and allow you to connect easily by shorting to mode pin to ground.
Thanks for the great guide! It helped me recover an FC with broken usb port.
i would like to OSB for my diatone 2017 GT-200S Stretch, with Fury 3 Flight Controller, but my usb is broken and can not solder back on or any wiring, I am able to connect via Uart 1 and used custom download flash update to Fury 3 3.16, but that does not get me OSB to get visual on my Frsky Googles, any Idea how to create custom Hex fil to default MSP to Uart 1, so I can flash to Fury3OSB Ver 3.32
Do my old settings get erased by installing the custom firmware ? like pids , etc, …
can you make it for butterflight 3.5?
Can this all be done with one of those ST-Link V2s?
For VCP case “One way of doing it is to flash the FC with a special firmware that by default has UART1 enabled for MSP USB connection. .”
How do you flash the FC if the usb is broken. Did I miss something ???
You can flash the fc through the uart1. Thats not the problem… afterwards you need msp activated on uart1 otherwise you can t connect and configure the fc. So you need a special build firmware where msp is activated on uart1…. in the above mentioned link can you get duch a firmware
Connect ftdi to uart1, bridge boot pads/press boot button. Bootloader is always active on uart1
Hi. I tried connecting ftdi to uart 1 but it doesn’t connect in DFU mode. It seems that there is not bootloader in uart1 at all. Any idea how to do it? Am I missing something?
My steps:
* Connect ftdi to FC (RX to TX, TX to RX, 5v, GND)
* Press boot button
* Connect FTDI to computer
* The FC is not in DFU mode so it can’t be flashed
Is there anyone who can tell me how a special firmware is done? Just activate msp on uart1?
Yes that’s pretty much it.
can i use st-link instead of ftdi?
I think you can, but I have never tried :)