I am trying to connect to a 3D printer board using 3 wire serial, that is no CTS and RTS. I had a Wemos wifi module on it previously so I know it works. Now I need to use my BanaPi M2 Zero to control it thorough the same port, the Wemos has been removed and not going back. I keep getting a failure to initialize when I try to connect to the board.
I am trying to use Pins 8 & 10 which is supposed to be UART 3 = /dev/ttyS3 from what I understand.
Questions:
How can I test the port? I have Minicom installed.
How do I set the parameters to disable CTS and RTS?
What flow control should I be using? Software?
Here is my setup:
armbianEnv.txt
verbosity=1
bootlogo=false
console=both
disp_mode=1920x1080p60
overlay_prefix=sun8i-h3
rootdev=UUID=e7e80086-a15f-4f2e-825d-9913c71ff19c
rootfstype=ext4
usbhost0
overlays=uart3 usbhost0
param_uart3_rtscts (bool)
Enable RTS and CTS pins
Optional
Default: 0
Set to 1 to enable CTS and RTS pins
usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u
Is that the correct parameters fro disabling RTS and CTS for 3 wire serial? I am using RX and TX cross connected as well as ground. Both boards are independently powered.
Other data:
My serial port seems to be working, see bold line:
dmesg | grep tty
[ 0.000000] Kernel command line: root=UUID=e7e80086-a15f-4f2e-825d-9913c71ff19c rootwait rootfstype=ext4 console=ttyS0,115200 console=tty1 hdmi.audio=EDID:0 disp.screen0_output_mode=1920x1080p60 consoleblank=0 loglevel=1 ubootpart=bfca11dd-01 ubootsource=mmc usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_fb_mem_reserve=16 cgroup_enable=memory swapaccount=1
[ 0.000352] printk: console [tty1] enabled
[ 2.223565] printk: console [ttyS0] disabled
[ 2.223659] 1c28000.serial: ttyS0 at MMIO 0x1c28000 (irq = 44, base_baud = 1500000) is a 16550A
[ 2.223915] printk: console [ttyS0] enabled
[ 2.225223] 1c28400.serial: ttyS1 at MMIO 0x1c28400 (irq = 45, base_baud = 1500000) is a 16550A
[ 2.225410] serial serial0: tty port ttyS1 registered
[ 2.226212] 1c28c00.serial: ttyS3 at MMIO 0x1c28c00 (irq = 46, base_baud = 1500000) is a 16550A
[ 6.072173] systemd[1]: Created slice system-serial\x2dgetty.slice.
[ 7.101175] systemd[1]: Found device /dev/ttyGS0.
[ 8.576630] systemd[1]: Found device /dev/ttyS0.
Second Test:
sudo setserial -g /dev/ttyS3
/dev/ttyS3, UART: 16550A, Port: 0x0000, IRQ: 46