Ever discovered your self with a bricked ExpressLRS receiver after a foul firmware replace? Or are you unable to flash your RX utilizing FC Passthrough nor WiFi? That is the place an FTDI dongle comes into play. On this information, I’ll stroll you thru the method of flashing ExpressLRS receivers through UART utilizing an FTDI programmer, such because the Radiomaster USB UART Flasher.
Why Use FTDI for Firmware Updates?
Whereas the best strategies to replace firmware are through Betaflight Passthrough or Wi-Fi (which I’ve lined in a earlier tutorial), there are situations the place these strategies may fail, comparable to a lack of connection. These points may end up in bricked receivers, the place the bootloader turns into corrupted.
An FTDI programmer, which permits flashing through UART, can come to the rescue. This methodology will also be helpful if you happen to’re not utilizing a flight controller or don’t have entry to Wi-Fi. It’s a flexible resolution that works with all manufacturers of ELRS receivers, for each 2.4GHz and 900MHz, with out the necessity for specialised software program.
For this process, you’ll want a USB to serial programming device, generally often known as an FTDI Programmer. Many producers supply devoted instruments for this goal, such because the Radiomaster USB UART Flasher, obtainable right here:
Whereas BetaFPV additionally presents the same device, the ExpressLRS Restoration Dongle (https://oscarliang.com/product-9zim), I’ll be utilizing the Radiomaster mannequin on this demonstration. The steps, nevertheless, are related for each.
A generic FTDI programmer is a less expensive choice (https://oscarliang.com/fpv-tools/#FTDI-Adapter), although it lacks the comfort of spring-loaded pins and different devoted harness that facilitate solder-free connections.
The FTDI programmer is easy to make use of. You’ll be utilizing 4 pins: RX, TX, VCC, and GND. VCC is 5V, GND is floor, and RX/TX are the info connection.
Step 1 – Plug in FTDI Dongle
Begin by opening the ExpressLRS Configurator and noting the obtainable COM Port (COM port quantity may be totally different in your pc).
After connecting the FTDI dongle to your pc, choose the newly appeared COM port. If no new COM port seems, you could want to put in the cp2102usb driver.
Step 2 – Join Receiver to FTDI Dongle
To replace through FTDI, the receiver have to be in boot mode.
This usually entails holding down the boot button on the receiver whereas connecting it to the FTDI Dongle (you possibly can launch the button as soon as the LED activates). Some receivers might require bridging two solder pads as a substitute of urgent a button (you possibly can take away the solder bridge after flashing).
Join the receiver to the FTDI Dongle utilizing the spring-loaded pins (whereas holding down the boot button). Right here’s the connection order to comply with:
- VCC – 5V
- GND – GND
- TX – RX
- RX – TX
Ought to I take advantage of 5V or 3.3V? For many ExpressLRS receivers, the 5V setting is suitable.
The Radiomaster UART Flasher additionally features a cable harness for receivers with out solder pads.
As soon as related, the receiver ought to energy up with a strong LED, indicating it’s in boot mode and able to be flashed.
Step 3 – ExpressLRS Configurator
Proceed with the usual setup within the ExpressLRS Configurator. Select your firmware model, gadget class, and particular mannequin. Make sure the flash methodology is about to UART.
Configure the remainder in response to your preferences, and ensure the COM port of your FTDI programmer.
Step 4 – Begin the Replace
Click on on ‘Construct & Flash’ to provoke the replace. As soon as the method completes efficiently, you possibly can disconnect the receiver from the FTDI dongle.
Understanding the way to replace ExpressLRS receivers through FTDI is very helpful, notably when different approaches fail. This tutorial goals to supply a transparent, step-by-step information to effectively get well and improve your ELRS RX utilizing an FTDI programmer, such because the Radiomaster USB UART Flasher. This course of may save your bricked RX from being discarded. Bear in mind, all the time double-check your connections and settings to make sure a profitable replace.