Tips: Pull out the plastic locking bar carefully so as not to break it.

Two methods to get the Frsky telemetry working, No.1 or No.2

Update your XSR with latest firmware.  

No.1. Enable SoftSerial_TX on S5 or S6 pad

• Don’t need to break the RX cover. Use the inverted TLM signal on the socket.
• Type “resource motor 5 none” in CLI, ENTER,
• Type “resource serial_tx 11 A15” in CLI, ENTER
• Type “Save”, ENTER
• Connect the inverted telemetry signal to S5 pad

No.2. Non-inversion hacks on receiver

• F405 MCU is not equipped with UART port inverters
• Need non-inversion hacks to get the Frsky SmartPort working.
• Connect one of F4 UART-TXs to the non-inverted telemetry signal pad(Yellow circle)

Press & hold the boot button & connect the USB to your computer.

Then release the button, the FC will enter the Boot Mode.

• Zadig 2.3
• STM32 Virtual Com Port driver