A20-OLinuXino-Lime UART ports

[Anushka]

I am using olimex A20 UART port for data communication but only UART0 is responding other UART ports are not working. Also UART0 is having problem it is not working well I am using RS232 to transmit and receive the data from computer via UART cable but my data is not received properly. 
I want to use other UART ports like UART3 as PG6(tx) &PG7(rx) but I am not getting any output.
Here is my code,
ser = serial.Serial("/dev/ttyS3" , 9600, timeout = 0.5)
receivedString = ser.readline().decode("utf-8")
print(receivedString)

I get empty string as my output.

[LubOlimex]

Are you using Olimage Linux? Did you run olinuxino-config script to enable more UARTs?

Refer to this document: https://github.com/OLIMEX/OLINUXINO/blob/master/DOCUMENTS/OLIMAGE/Olimage-guide.pdf

[Anushka]

Yes I am using olimage Linux. I can not find location of config script. Can you tell its location commands?

[mactronica]

The encoded address (/soc@1c00000/serial@1c28c00) in DTS is the wrong one and refers to UART1 instead of UART3.
You can see it here:

https://github.com/OLIMEX/olinuxino-overlays/blob/master/sun7i-a20/sun7i-a20-uart3.dts

[JohnS]

The encoded address (/soc@1c00000/serial@1c28c00) in DTS is the wrong one and refers to UART1 instead of UART3.
You can see it here:

https://github.com/OLIMEX/olinuxino-overlays/blob/master/sun7i-a20/sun7i-a20-uart3.dts

Looks correct to me, referring to the A20 doc.

John

[LubOlimex]

Yes I am using olimage Linux. I can not find location of config script. Can you tell its location commands?

It is just you can type and execute commands in the command line interface as soon as you login.

How do you access the board?

[mactronica]

Looks correct to me, referring to the A20 doc.

John

I'm sorry. My statement is not accurate. It's UART3 but it's mapped on ttyS1:

Code Select Expand


olimex@a20-olinuxino:~$ dmesg | grep tty
[    0.000000] Kernel command line: root=PARTUUID=de3c5b85-01 rootwait console=ttyS0,115200 panic=10 loglevel=4
[    1.079397] printk: console [ttyS0] disabled
[    1.079534] 1c28000.serial: ttyS0 at MMIO 0x1c28000 (irq = 59, base_baud = 1500000) is a 16550A
[    1.096391] printk: console [ttyS0] enabled
[    1.098798] 1c28c00.serial: ttyS1 at MMIO 0x1c28c00 (irq = 60, base_baud = 1500000) is a 16550A
[    1.100638] 1c29000.serial: ttyS2 at MMIO 0x1c29000 (irq = 61, base_baud = 1500000) is a 16550A
[    1.102874] 1c29400.serial: ttyS3 at MMIO 0x1c29400 (irq = 62, base_baud = 1500000) is a 16550A
[    1.104632] 1c29800.serial: ttyS4 at MMIO 0x1c29800 (irq = 63, base_baud = 1500000) is a 16550A
[    1.106474] 1c29c00.serial: ttyS5 at MMIO 0x1c29c00 (irq = 64, base_baud = 1500000) is a 16550A
[    6.771787] systemd[1]: Created slice system-getty.slice.
[    6.812537] systemd[1]: Created slice system-serial\x2dgetty.slice.



[JohnS]

Is there a problem with uart2.dts?

It uses
serial2 = "/soc/serial@1c28800";

which I thought might be
serial2 = "/soc@1c00000/serial@1c28800";

Is there no ttySx for it?

John

[Anushka]

Yes I am using olimage Linux. I can not find location of config script. Can you tell its location commands?

It is just you can type and execute commands in the command line interface as soon as you login.

How do you access the board?

I typed that comments on terminal but its not working.It is showing commands not found after typing the code in the doc https://github.com/OLIMEX/olinuxino-overlays/blob/master/sun7i-a20/sun7i-a20-uart3.dts

[LubOlimex]

Umm it looks like this here: https://i.imgur.com/GgOgdrq.jpg

How do you access the board?

[Anushka]

Umm it looks like this here: https://i.imgur.com/GgOgdrq.jpg

How do you access the board?

I access the board through terminal. I run the code but its not working. When I typed command olinuxino- on terminal it said commands not found.

[JohnS]

As in the image posted, the command is olinuxino-overlay

John

[LubOlimex]

Umm it looks like this here: https://i.imgur.com/GgOgdrq.jpg

How do you access the board?

I access the board through terminal. I run the code but its not working. When I typed command olinuxino- on terminal it said commands not found.

"olinuxino-" then you press "TAB" key to auto-complete all items whose name start with "olinuxino-"