NANOPC-T4 UART4 ttyS4 TX is not working.
Posted: Mon Mar 21, 2022 4:55 am
I am not able to send data from the NANO-PC-T4 on ttyS4.
I am able to receive the data.
Setup
Nano-pc-t4 ----> USB to Serial --> PC
(40 pin header) (CP1201)
(PC-T4 Tx Pin-19 ------------> Rx of USB to Serial)
(PC-T4 Tx Pin-21 ------------> Tx of USB to Serial)
What I type in the PC terminal is seen in the NANO-PC-T4.
What I type in NANO-PC-T4 is not seen in the PC terminal.
Is there any pull-up needed on the TX ?
I could see that /proc/tty/driver/serial , UART-4 counters are incremented.
4: uart:16550A mmio:0xFF370000 irq:40 tx:21 rx:20
Can you tell me how to debug this ?
I am able to receive the data.
Setup
Nano-pc-t4 ----> USB to Serial --> PC
(40 pin header) (CP1201)
(PC-T4 Tx Pin-19 ------------> Rx of USB to Serial)
(PC-T4 Tx Pin-21 ------------> Tx of USB to Serial)
What I type in the PC terminal is seen in the NANO-PC-T4.
What I type in NANO-PC-T4 is not seen in the PC terminal.
Is there any pull-up needed on the TX ?
I could see that /proc/tty/driver/serial , UART-4 counters are incremented.
4: uart:16550A mmio:0xFF370000 irq:40 tx:21 rx:20
Can you tell me how to debug this ?