enable uart2 is posiible on Omega2+??



  • 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



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

    any idea? somebody did it?



  • @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
    0_1544537223405_MT7688_UART2_pin_share.png



  • @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



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



  • @György-Farkas that's true



  • @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.



  • 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!



  • @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.


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