X86J4105 & serial RS-232 on Linux

[pcarmo]

Hi,

I’m new to X86J4105 hardware and I have some questions about the availability of a serial RS-232 interface or something that I could use to make the connection of an old APC UPS (with an DB9 RS-232 interface) to the X86J4105 board possible.

What are my best options for connecting the UPS to the X86J4105?

Will I see a /dev/ttyS0 or something similar on the OS (Linux)?

Do I need a additional hardware to connect/convert the 4 pins UART to a RS-232 connector?
Something like this : http://wiki.seeedstudio.com/RS-232_To_TTL_Conveter-MAX3232IDR/

Thanks,
Paulo Carmo

[wx4cb]

@pcarmo dev/ttyS4 are the UART pins on the 40 pin header, the 4 pin header we haven’t worked out what it is yet - see this thread:.

As far as a UPS I would suggest using a USB-Serial dongle with an FTDI chipset that would provide the correct RS232 voltages to the UPS. don’t forget, the standard RS232 is +/- 12 volts and the header pins are at TTL login (+/- 5v) so you can damage them if you hook them up directly.

Arduino core doesn't appear to be working

I received my NVME SSD drive a day early (yay Amazon!), got it installed, and then installed Ubuntu 18.04. That OS really makes this board perform well–very pleasant experience for this old Linux user! I’m sure Windows would be fine as well, but I prefer Linux. That being said, I’ll continue trying to figure out this 4-pin header serial interface this week. @Baozhu, do you have any additional documentation you could give us on this little 4-pin header next to the Arduino header? My ultimate int…

[pcarmo]

Hello wx4cb,

Thanks for the information. Connecting through USB-Serial converter was an option I was trying to avoid, but nevertheless it is a possible solution.

Concerning the 4 pins header near the 28 pin header I was expecting to be an UART as it writeen in the wiki: http://wiki.seeedstudio.com/ODYSSEY-X86J4105/#pinout-diagram
But I guest if you are point to the other thread is because it is not

Regards,
Paulo Carmo

[wx4cb]

@pcarmo

I have finally had a chance to figure it out… the silk screen on the 4 pin header is not correct as per the image

go take a loook here Serial Port device names at what I and @tcbetka figured 0out the past few days.

it’s been acknowledged by seeed that there is an error and should be corrected in the wiki already, but i proved the correct device names.

Basically

SerialUSB is the serial monitor (still has issues sometimes locking up the ide)
“Serial” is the 4 pin header
“Serial1” is the 28 pin header D0/D1
/dev/ttyS4 is the 40 pin header device accessible from linux.
/dev/ttyACM0 is the linux device node that is :“SerialUSB” so Theoretically, you could write SAMD code to use the Serial SUB library and talk to it via /dev/ttyACM0 and still have 3 serial ports available