does RevPi Connect S support Using RS485 as a Serial Console?
does RevPi Connect S support Using RS485 as a Serial Console?
In this page, it says revpi-flat can use RS485 as a Serial Console without HDMI:
https://revolutionpi.com/en/tutorials/o ... utzen-flat
We have RevPi Connect S. Does it support this feature the same?
Regards
Peter
https://revolutionpi.com/en/tutorials/o ... utzen-flat
We have RevPi Connect S. Does it support this feature the same?
Regards
Peter
Re: does RevPi Connect S support Using RS485 as a Serial Console?
Hello Peter, this should be possible, I have just successfully created a test setup.
However, not with a RevPi Connet S but with a RevPi Connect 4, where it works like this. I have checked which ttyAMA* is available - ttyAMA5:
I then changed the /boot/config.txt as follows
Using a logic analyzer, I was able to determine that data was transferred
Please ensure which settings are necessary on your system and change this solution accordingly, then it should work.
However, not with a RevPi Connet S but with a RevPi Connect 4, where it works like this. I have checked which ttyAMA* is available - ttyAMA5:
I then changed the /boot/config.txt as follows
Code: Select all
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 fsck.repair=yes rootwait nosplash plymouth.ignore-serial-consoles console=ttyAMA5,115200n8
Please ensure which settings are necessary on your system and change this solution accordingly, then it should work.
Re: does RevPi Connect S support Using RS485 as a Serial Console?
Hi Dirk
Thank you for the confirmation. Will give it a try on mine when I get a USB to RS485 adapter.
Regards
Peter
Thank you for the confirmation. Will give it a try on mine when I get a USB to RS485 adapter.
Regards
Peter
- p.rosenberger
- KUNBUS
- Posts: 90
- Joined: 03 Jul 2020, 11:07
Re: does RevPi Connect S support Using RS485 as a Serial Console?
Hi Peter,
it should be possible to use the RS485 as console. But be aware, that the RS485 on the Connect(+/S) is connected via USB. This has some impact on some minor use-cases. So you only get output from the console after the USB subsystem is initialized. This is later in the kernel startup. But after this it should work just fine.
Best regards,
Philipp
it should be possible to use the RS485 as console. But be aware, that the RS485 on the Connect(+/S) is connected via USB. This has some impact on some minor use-cases. So you only get output from the console after the USB subsystem is initialized. This is later in the kernel startup. But after this it should work just fine.
Best regards,
Philipp
Re: does RevPi Connect S support Using RS485 as a Serial Console?
This is my device /dev details:
I tried to change cmdline.txt to use /dev/ttyAMA0, but it seemed to break my application with Revpi DIO module. Maybe ttyAMA0 is the Revpi DIO module interface.
Then I saw /dev/ttyRS485, and I thought maybe that is the dev I should use, and I changed cmdline.txt as follows:
But I connect the COM port with baudrate 115200 with putty on Windows, I just got weird characters.
```
▒▒▒@@B▒▒'▒▒▒▒▒+▒▒▒▒G@P▒▒▒▒▒+▒▒▒▒@@B▒▒'▒▒▒▒B▒+▒▒▒▒G@P▒▒▒▒ ▒+▒▒▒▒@@B▒▒'▒▒▒▒B ▒+▒▒▒▒G@P▒▒▒▒▒+▒▒▒▒@@B▒▒'▒▒▒▒ ▒+▒▒▒▒G@P▒▒▒▒ ▒+▒▒▒▒G@P▒▒▒▒▒+▒▒▒▒@@W$▒▒▒▒ Pw▒▒▒BA@ҁ▒▒▒@@B▒▒'▒▒▒▒ ▒+▒▒▒▒B@@W$▒▒▒▒G Pw▒▒▒BA@ҁ▒▒▒@@B▒▒'▒▒▒▒ ▒+▒▒▒▒@@W▒▒▒▒G Pw▒▒▒A@ҁ
```
I use this RS485 to USB adapter https://core-electronics.com.au/industr ... erter.html, and wired the adapter A+ to RS485 interface P on the RS485 interface, and B- to N interface.
OS version:
Any suggestion?
Thanks
Peter
Code: Select all
root@HiveController:/boot# ls /dev/
autofs fuse loop1 mmcblk0 pts ram6 serial tty11 tty23 tty35 tty47 tty59 ttyS0 vcs2 vcsu video14
block gpiochip0 loop2 mmcblk0boot0 ram0 ram7 serial0 tty12 tty24 tty36 tty48 tty6 ttyUSB0 vcs3 vcsu1 video15
btrfs-control gpiochip1 loop3 mmcblk0boot1 ram1 ram8 serial1 tty13 tty25 tty37 tty49 tty60 ttyUSB1 vcs4 vcsu2 video16
bus gpiochip2 loop4 mmcblk0p1 ram10 ram9 shm tty14 tty26 tty38 tty5 tty61 ttyUSB2 vcs5 vcsu3 video18
cachefiles gpiochip3 loop5 mmcblk0p2 ram11 random snd tty15 tty27 tty39 tty50 tty62 uhid vcs6 vcsu4 video20
char gpiochip4 loop6 mmcblk0rpmb ram12 raw spidev0.0 tty16 tty28 tty4 tty51 tty63 uinput vcsa vcsu5 video21
console hwrng loop7 mqueue ram13 rfkill stderr tty17 tty29 tty40 tty52 tty7 urandom vcsa1 vcsu6 video22
cuse i2c-1 loop-control net ram14 rpivid-h264mem stdin tty18 tty3 tty41 tty53 tty8 v4l vcsa2 vga_arbiter video23
disk initctl mapper null ram15 rpivid-hevcmem stdout tty19 tty30 tty42 tty54 tty9 vchiq vcsa3 vhci watchdog
dma_heap input media0 piControl0 ram2 rpivid-intcmem tty tty2 tty31 tty43 tty55 ttyAMA0 vcio vcsa4 video10 watchdog0
fb0 kmsg media1 port ram3 rpivid-vp9mem tty0 tty20 tty32 tty44 tty56 ttyConBridge vc-mem vcsa5 video11 zero
fd log media2 ppp ram4 rtc tty1 tty21 tty33 tty45 tty57 ttyprintk vcs vcsa6 video12
full loop0 mem ptmx ram5 rtc0 tty10 tty22 tty34 tty46 tty58 ttyRS485 vcs1 vcsm-cma video13
root@HiveController:/boot# ls -l /dev/ttyRS485 /dev/ttyUSB1 /dev/ttyAMA0
crw-rw---- 1 root dialout 204, 64 Mar 5 14:47 /dev/ttyAMA0
lrwxrwxrwx 1 root root 7 Mar 5 14:22 /dev/ttyRS485 -> ttyUSB1
crw-rw---- 1 root dialout 188, 1 Mar 5 14:47 /dev/ttyUSB1
Code: Select all
dwc_otg.lpm_enable=0 console=ttyAMA0,115200n8 root=/dev/mmcblk0p2 rootfstype=ext4 fsck.repair=yes rootwait nosplash plymouth.ignore-serial-consoles
Code: Select all
dwc_otg.lpm_enable=0 console=ttyRS485,115200n8 root=/dev/mmcblk0p2 rootfstype=ext4 fsck.repair=yes rootwait nosplash plymouth.ignore-serial-consoles
```
▒▒▒@@B▒▒'▒▒▒▒▒+▒▒▒▒G@P▒▒▒▒▒+▒▒▒▒@@B▒▒'▒▒▒▒B▒+▒▒▒▒G@P▒▒▒▒ ▒+▒▒▒▒@@B▒▒'▒▒▒▒B ▒+▒▒▒▒G@P▒▒▒▒▒+▒▒▒▒@@B▒▒'▒▒▒▒ ▒+▒▒▒▒G@P▒▒▒▒ ▒+▒▒▒▒G@P▒▒▒▒▒+▒▒▒▒@@W$▒▒▒▒ Pw▒▒▒BA@ҁ▒▒▒@@B▒▒'▒▒▒▒ ▒+▒▒▒▒B@@W$▒▒▒▒G Pw▒▒▒BA@ҁ▒▒▒@@B▒▒'▒▒▒▒ ▒+▒▒▒▒@@W▒▒▒▒G Pw▒▒▒A@ҁ
```
I use this RS485 to USB adapter https://core-electronics.com.au/industr ... erter.html, and wired the adapter A+ to RS485 interface P on the RS485 interface, and B- to N interface.
OS version:
Code: Select all
cat /etc/*release
PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
NAME="Raspbian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
Thanks
Peter
Re: does RevPi Connect S support Using RS485 as a Serial Console?
Hi Peter, ttyAMA0 is the PiBridge and therefore cannot work. "ttyRS485" is a symlink that points to the actual UART.
As this UART is only set later during booting, the target must be used. Query can be made with readlink /dev/ttyRS485 i.e.
As this UART is only set later during booting, the target must be used. Query can be made with readlink /dev/ttyRS485 i.e.
Code: Select all
pi@RevPi99988:~ $ readlink /dev/ttyRS485
ttyAMA5