enable uart2 is posiible on Omega2+??

pablo campos

Hello all,
I need to enable uart2 on Omega2+. I need 2 uarts but I wouldn't like to disable Console log on uart0.
On uart0 log, omega2-ctrl and some forums I saw there are 3 uarts (tx2/rx2 on pins 16/17), but only 2 are available.
How can I enable and use it?

thanks

pablo campos

I have to say that just enabling uart2 in omega2-ctrl doesn't seem to work.

any idea? somebody did it?

György Farkas

@pablo-campos It is not possible because UART_TXD2, UART_RXD2 share GPI#O20, GPIO#21 pins respectively and those pins are not exposed on Omega2(+).
You could plug practically any cheap USB-to-Serial (3.3V or 5V TTL or even RS232 etc.) converter module in the Omega's USB Host Port instead.

Mediatek MT7688 Datasheet

Gnichi Mohamed

@pablo-campos said in enable uart2 is posiible on Omega2+??:

On uart0 log, omega2-ctrl and some forums I saw there are 3 uarts (tx2/rx2 on pins 16/17), but only 2 are available.

The HLK-7866 module exposes UART2 pins, you need to compile new u-boot and modify the Kernel and then you can get UBOOT and Kernel console on UART2

György Farkas

@Gnichi-Mohamed See also Omega2S
Surface Mount Packaged version of the Omega2

Gnichi Mohamed

@György-Farkas that's true

György Farkas

@pablo-campos It is possible ... so I was wrong - again
After this command omega2-ctrl gpiomux set spi_s pwm01_uart2 Omega2(+)'s UART2 (ttyS2) works well using GPIO16 as TX2 and GPIO17 as RX2 (8N1 default BAUD rate 9600 bps).

# Omega2+ FW v0.2.2 b201

root@Omega-5BE1:~# omega2-ctrl gpiomux set spi_s pwm01_uart2
set gpiomux spi_s -> pwm01_uart2

root@Omega-5BE1:~# omega2-ctrl gpiomux get
Group i2c - [i2c] gpio 
Group uart0 - [uart] gpio 
Group uart1 - [uart] gpio pwm01 
Group uart2 - [uart] gpio pwm23 
Group pwm0 - pwm [gpio] 
Group pwm1 - pwm [gpio] 
Group refclk - refclk [gpio] 
Group spi_s - spi_s gpio [pwm01_uart2] 
Group spi_cs1 - [spi_cs1] gpio refclk 
Group i2s - i2s [gpio] pcm 
Group ephy - [ephy] gpio 
Group wled - wled [gpio]

I have also tried it successfully with
picocom -b 115200 /dev/ttyS2 on Omega2+ and
picocom -b 115200 /dev/ttyUSB0 on Ubuntu 18.4.1 LTS with an FTDI232 USB-to-3.3V Serial module.

Good luck.

pablo campos

Thanks György Farkas,

Using "omega2-ctrl gpiomux set spi_s pwm01_uart2" enable the uart2 and works fine!

I was using "omega2-ctrl set uart2 uart"
and I geting:
Group i2c - [i2c] gpio
Group uart0 - [uart] gpio
Group uart1 - [uart] gpio pwm01
Group uart2 - [uart] gpio pwm23
Group pwm0 - pwm [gpio]
Group pwm1 - pwm [gpio]
Group refclk - refclk [gpio]
Group spi_s - spi_s [gpio] pwm01_uart2

But didn't work. With the config that György Farkas suggested, is working!!

In fact the config of Group uart2 seems to be irrelevant.
I have:
...
Group uart2 - uart gpio [pwm23]
....
Group spi_s - spi_s gpio [pwm01_uart2]

and still working...

Thanks again!

György Farkas

@pablo-campos said in enable uart2 is posiible on Omega2+??:

I was using "omega2-ctrl gpiomux set uart2 uart"
...
(omega2-ctrl gpiomux get)
Group uart2 - [uart] gpio pwm23
...
In fact the config of Group uart2 seems to be irrelevant.

Here you are some details from the Mediatek MT7688 Datasheet:

3.3 Pin Sharing Schemes
3.3.1 GPIO pin share scheme
--------------+-------------+-----------
I/O Pad Group | Normal Mode | GPIO Mode
--------------+-------------+-----------
SPIS          | MDI_RP_P1   | GPIO#16
              | MDI_RN_P1   | GPIO#17
--------------+-------------+-----------
UART2 / eMMC  | MDI_TP_P2   | GPIO#20
              | MDI_TN_P2   | GPIO#21```


3.3.21 SPIS pin share scheme
----------+-----------+-----------+---------+---------------------+---------------------------
Controlled|   b0000   |                   b1111                   | EPHY_APGIO_AIO_EN bit 4:1 
    by    +-----------+-----------+---------+---------+-----------+---------------------------
          |           |    b00    |   b01   |   b10   |    b11    | SPIS_MODE bit 3:2
----------+-----------+-----------+---------+---------+-----------+---------------------------
Pin Name  |
----------+-----------+-----------+---------+---------+-----------+
MDI_RP_P1 | MDI_RP_P1 | SPIS_MISO | GPIO#16 |         | UART_TXD2 |
MDI_RN_P1 | MDI_RN_P1 | SPIS_MOSI | GPIO#17 |         | UART_RXD2 |

                                                       [SPIS_MODE]
                                                        PWM CH0/1
                                                        and UART2


3.3.18 UART2 pin share scheme
----------+-----------+-----------+---------+-------------------+---------------------------
Controlled|   b0000   |                   b1111                 | EPHY_APGIO_AIO_EN bit 4:1
    by    +-----------+-----------+---------+---------+---------+---------------------------
          |           |    b00    |   b01   |   b10   |   b11   | UART2_MODE bit 27:26
----------+-----------+-----------+---------+---------+---------+---------------------------
Pin Name  |
----------+-----------+-----------+---------+---------+---------+
MDI_TP_P2 | MDI_TP_P2 | UART_TXD2 | GPIO#20 | PWM_CH2 | eMMC_D5 |
MDI_TN_P2 | MDI_TN_P2 | UART_RXD2 | GPIO#21 | PWM_CH3 | eMMC_D4 |

                       [UART2_MODE]
                       UART-Lite #2

omega2-ctrl gpiomux set uart2 uart is really irrevelant on Omega2(+) but both configs should be OK on Omega2(+)S (not the same time of course).
I don't have it so I can't try the other config.

Pavel Negrobov

I am using UART1 (pins 45, 46) with python pyserial library without any utilities. All works good.