RS485 on UART and GPIO

This forum is for users of Microchip MPUs and who are interested in using Linux OS.

Moderator: nferre

Evolynx
Posts: 3
Joined: Tue Oct 16, 2018 10:15 am

RS485 on UART and GPIO

Mon Nov 05, 2018 12:41 pm

Hello,

I am working on the SAMA5D27-SOM1-EK and I try to use an RS485 with automatic direction control with RTS PIN (switch between transmit and receive) with an UART port and 1 GPIO. I have already do that with a FLEXCOM but I need's more.

I try do it with the exemple gives at :
- /Documentation/devicetree/bindings/serial/rs485.txt.
- /Documentation/serial/serial-rs485.txt

And I success in activate an uart on microbus, and I success to activate the RTS PIN but I can not succeed in rise and fall the RTS signal between transmit and receive mode within a simple “open” “write” “read” “close” program.

Did I choose the right driver (at91sam9260-usart) to do that ? Is there any options I forgive ?

Thanks for help
blue_z
Location: USA
Posts: 1759
Joined: Thu Apr 19, 2007 10:15 pm

Re: RS485 on UART and GPIO

Mon Nov 05, 2018 11:02 pm

Evolynx wrote:
Mon Nov 05, 2018 12:41 pm
I am working on the SAMA5D27-SOM1-EK and I try to use an RS485 ...with an UART port and 1 GPIO.
...
Did I choose the right driver (at91sam9260-usart) to do that ? Is there any options I forgive ?
The RS-485 support in the atmel_serial.c driver depends on hardware and a capability that does not exist in the Atmel UART peripheral.
You would have to hack the driver to control a pseudo-RTS pin.

Regards

Return to “LINUX”

Who is online

Users browsing this forum: Bing [Bot] and 3 guests