multiplexing

[jasonroyyy]

Hello,

I have an A20-OLinuXino-Lime2 board and I'm attempting to use uart3. I've observed that uart3 is multiplexed on gpio1 pins 17 and 19. Following the instructions in the manual, I executed the command "~#olinuxino-overlay" to enable uart3. After rebooting, I confirmed that uart3 was successfully enabled. Additionally, when I run the command "ls -l /dev/ttyS3," it displays the correct output. However, when I performed a test by entering "echo 'some string' > /dev/ttyS3," I didn't observe any activity on the oscilloscope. I'm uncertain about the missing step or if there's something I overlooked. Any assistance you can provide would be greatly appreciated. Thank you for your help.

[LubOlimex]

Did you first try with loopback tests? Connect pins 17 and 19 together and open terminal what you send you should receive...