Hello,
I am making a board coupled to a NanoPi Neo Core, and a RS485 converter to its UART2.
The chip is a MAX1478 and I use the RTS (PA2).
this is my armbianEnv
verbosity=1
bootlogo=false
disp_mode=1920x1080p60
overlay_prefix=sun8i-h3
overlays=cpu-clock-1.2GHz-1.3v i2c0 i2c1 uart1 uart2 usbhost0 usbhost1 usbhost2
rootdev=UUID=a37457d6-57d2-4f17-a684-157b1a309a73
rootfstype=ext4
user_overlays=neo-core-stable-mac double-spi ds1307
param_uart2_rtscts=1
param_uart3_rtscts=1
usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u
if i run the command,
cat /proc/tty/driver/serial |head -8
uart:16550A mmio:0x01C28800 irq:53 tx:120 rx:0 RTS|DTR
command
mbpoll -a139 -b9600 -t3 -c2 -m rtu -R /dev/ttyS2 -l 500
mbpoll 1.4-12 - FieldTalk(tm) Modbus(R) Master Simulator
Copyright © 2015-2019 Pascal JEAN, https://github.com/epsilonrt/mbpoll
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions; type 'mbpoll -w' for details.
Protocol configuration: Modbus RTU
Slave configuration...: address = [139]
start reference = 1, count = 2
Communication.........: /dev/ttyS2, 9600-8E1
t/o 1.00 s, poll rate 500 ms
Data type.............: 16-bit register, input register table
-- Polling slave 139... Ctrl-C to stop)
Read input register failed: Connection timed out
-- Polling slave 139... Ctrl-C to stop)
Read input register failed: Connection timed out
-- Polling slave 139... Ctrl-C to stop)
Read input register failed: Connection timed out
-- Polling slave 139... Ctrl-C to stop)
Read input register failed: Connection timed out
-- Polling slave 139... Ctrl-C to stop)
Read input register failed: Connection timed out
-- Polling slave 139... Ctrl-C to stop)
Apparently it is in RTS mode, it sends but it seems that it cannot receive. I do not know if it could be a failure that it does not change the sending / receiving.
I have to activate something else for the RS485 to work? How can I see if the RTS is working well?
@martinayotte talk about a patch but i dont know if it can work in my kernel.
Thanks in advance!