I've attached an I2C 20x4 LCD to an I2C multiplexer , then to my Arduino Due. It works fine, but only once the Arduino has been reset at least once after being powered up. This is what it looks like when you plug in the board and do nothing: [20230611_173416] This is what it's meant to look like …

20x4 LCD Displays Gargled Characters When Powering Up (Due)

sombody101 June 12, 2023, 11:40pm 12

That worked!
Thank you!

For the startup screen, I used a block of code found here.

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