I tried to connect st3215 servo to my Cubie A5E via UART gpios.
I enabled UART3 overlay. /dev/ttyAS3 device appeared, but any tests failed.
In rsetup I see error pins, corresponding to UART3.
With other UART4-7 I got the same (error gpios and failed tests with corresponding devs).
Is there support for UART3-7 gpios?
How can I enable my UART device?
The reason for the result of the rsetup gpio test showing “E” is that the pins are occupied because you have enabled UART. For the serial port test, you can use a loopback test: connect TX to RX, and use tools like picocom to test with the correct serial port baud rate settings.
If the input characters can be echoed back, it indicates that the serial port is working properly.
