Odroid C2 and UART for UPS monitoring

Hi All,

I’ve just added a UPS to my Odroid C2 (full operating system) and I would like to monitor its status. The UPS has UART support so I figured the easiest way is to connect the Odroid UART to the UPS UART (swapping Rx/Tx).

However when I look at the home assistant operating system I think only one UART is enabled for the console -

[    0.000000] Kernel command line: zram.enabled=1 zram.num_devices=3 systemd.machine_id=72e44107cee445de8ce7fedd4e3f813a fsck.repair=yes  root=PARTUUID=48617373-08 rootfstype=squashfs ro rootwait rauc.slot=B console=tty0 console=ttyAML0,115200n8
[    0.000262] printk: console [tty0] enabled
[    0.093659] c81004c0.serial: ttyAML0 at MMIO 0xc81004c0 (irq = 14, base_baud = 1500000) is a meson_uart
[    0.093710] printk: console [ttyAML0] enabled

So how can I enable, presumably, ttyAML1 ?

There is an application note here odroid-c2:application_note:gpio:uart [ODROID Wiki] but these seem to imply 2 UARTS are enabled by default (you can optionally condifure 4 in total).

I tried connecting to /dev/ttyS1 with microcom by this failed with an I/O error.