Connection failed Forced interrupt! Nextion to Arduino

Other Hardware 3rd Party Boards
1

Hello everyone,

I’m working with a 3.5-inch Nextion display connected to an Arduino Uno. I’m trying to upload a .tft file to the Nextion display using the Nextion Editor via COM3, but I keep encountering the error:

Connection failed
Forced interrupt!

This is what I’ve Tried So Far:

  1. Verified wiring:
    • Nextion TX → Arduino RX (Pin 0)
    • Nextion RX → Arduino TX (Pin 1)
    • Nextion 5V → Arduino 5V
    • Nextion GND → Arduino GND
  2. Checked COM port settings in the Nextion Editor:
    • Confirmed COM3 is correct.
    • Tried baud rates of 9600 and 115200.
  3. Ensured no other program is using the COM port.
  4. Used power source:
    • Powered the Nextion display directly from the Arduino Uno's 5V pin.

Questions:

  1. Can the Arduino Uno’s 5V reliably power a 3.5-inch Nextion display during uploads, or should I always use an external power source?
  2. Is the error caused by using the Arduino Uno as a serial interface instead of a dedicated USB-to-Serial converter like FT232 or CP2102?
  3. Could the reboot loop be due to insufficient power, and if so, what’s the best way to power both the Arduino and Nextion display for stable operation?

I’d appreciate any advice, troubleshooting tips, or alternative suggestions for uploading files successfully. Thank you in advance!

2

I’m trying to upload a .tft file to the Nextion display using the Nextion Editor via COM3

When you are using the Uno as a pass through USB to TT converter from the PC to the Nextion, I believe the Arduino/Nextion connection is Tx>Tx and Rx>Rx. The USB to TTL converter chip on the Uno (16U2 , Ch340) does the swapping around for you.

3

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.