Orange Pi Zero 2+ H5 can't communicate on UART1

Lee Fromage · December 15, 2017

Hello, I'm new to this forum and Armbian. I've got an Orange Pi Zero 2+ H5 running the Armbian_5.34.171121_Orangepizeroplus2-h5_Ubuntu_xenial_next_4.13.14 image. It's connected to a device via UART1 using pin 1 for 3.3V, 6 for GND, and 8/10 for TX/RX.

I've been trying unsuccessfully to use pyserial in a Python script to read data from the ttyS* devices, but I can't seem to cat anything from them either. I've tried moving the device to a RaspberryPi Zero W and I'm able to read the output from ttyS0 successfully. I did have to run raspi-config to enable the UART on the RPi, but I'm not aware of an equivalent on the OPi. I believe I added the uart1 overlay to my armbianEnv.txt correctly after searching this forum, but still no luck.

uname -a
Linux orangepizeroplus2 4.14.4-sunxi64 #11 SMP Thu Dec 7 11:55:12 CET 2017 aarch64 aarch64 aarch64 GNU/Linux

cat /boot/armbianEnv.txt
verbosity=1
console=both
overlay_prefix=sun50i-h5
overlays=usbhost2 usbhost3 uart1
rootdev=UUID=cb2b70ec-3706-45a4-94dc-81565e6a19d4
rootfstype=ext4
usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u

ls -al /dev/ttyS*
crw--w---- 1 root tty     4, 64 Dec 15 21:32 /dev/ttyS0
crw-rw---- 1 root dialout 4, 65 Dec 15 21:31 /dev/ttyS1
crw-rw---- 1 root dialout 4, 66 Dec 15 21:31 /dev/ttyS2
crw-rw---- 1 root dialout 4, 67 Dec 15 21:31 /dev/ttyS3

# From sun50i-h5-orangepi-zero-plus2.dtb:
uart1 {
		pins = "PG6", "PG7";
		function = "uart1";
		linux,phandle = <0x4f>;
		phandle = <0x4f>;
};

uart1_rts_cts {
		pins = "PG8", "PG9";
		function = "uart1";
		linux,phandle = <0x50>;
		phandle = <0x50>;
};
          
dmesg | grep tty
[    0.000000] Kernel command line: root=UUID=cb2b70ec-3706-45a4-94dc-81565e6a19d4 rootwait rootfstype=ext4 console=tty1 console=ttyS0,115200 panic=10 consoleblank=0 loglevel=1 ubootpart=67c048bb-01 usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u   cgroup_enable=memory swapaccount=1
[    0.000156] console [tty1] enabled
[    1.635116] console [ttyS0] disabled
[    1.655295] 1c28000.serial: ttyS0 at MMIO 0x1c28000 (irq = 25, base_baud = 1500000) is a U6_16550A
[    1.655346] console [ttyS0] enabled
[    1.675985] 1c28400.serial: ttyS1 at MMIO 0x1c28400 (irq = 26, base_baud = 1500000) is a U6_16550A

Any guesses what I'm doing wrong? Thank you.