Hi,
I am a new user of the BeagleBone Green and I have some troubles with the UART.
I have flashed the board with the bone-eMMC-flasher-debian-10.5-console-armhf-2020-08-25-1gb.img image.
I have updated the system with apt update && apt dist-upgrade and updated the kernel with cd /opt/scripts && git pull && /opt/scripts/tools/update_kernel.sh --lts-4_19 --ti-channel
$ uname -a
Linux beaglebone 4.19.94-ti-r59 #1buster SMP PREEMPT Mon Feb 8 19:17:16 UTC 2021 armv7l GNU/Linux
$ cat /etc/debian_version
10.8
I use the following /boot/uEnv.txt:
#Docs: http://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0
uname_r=4.19.94-ti-r59
#uuid=
#dtb=
###U-Boot Overlays###
###Documentation: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_Overlays
###Master Enable
enable_uboot_overlays=1
###
###Overide capes with eeprom
#uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo
#uboot_overlay_addr1=/lib/firmware/BB-UART5-00A0.dtbo
#uboot_overlay_addr1=<file1>.dtbo
#uboot_overlay_addr2=<file2>.dtbo
#uboot_overlay_addr3=<file3>.dtbo
###
###Additional custom capes
#uboot_overlay_addr4=<file4>.dtbo
#uboot_overlay_addr5=<file5>.dtbo
#uboot_overlay_addr6=<file6>.dtbo
#uboot_overlay_addr7=<file7>.dtbo
###
###Custom Cape
#dtb_overlay=<file8>.dtbo
###
###Disable auto loading of virtual capes (emmc/video/wireless/adc)
#disable_uboot_overlay_emmc=1
disable_uboot_overlay_video=1
disable_uboot_overlay_audio=1
disable_uboot_overlay_wireless=1
disable_uboot_overlay_adc=1
###
###PRUSS OPTIONS
###pru_rproc (4.14.x-ti kernel)
#uboot_overlay_pru=AM335X-PRU-RPROC-4-14-TI-00A0.dtbo
###pru_rproc (4.19.x-ti kernel)
uboot_overlay_pru=AM335X-PRU-RPROC-4-19-TI-00A0.dtbo
###pru_uio (4.14.x-ti, 4.19.x-ti & mainline/bone kernel)
#uboot_overlay_pru=AM335X-PRU-UIO-00A0.dtbo
###
###Cape Universal Enable
enable_uboot_cape_universal=1
###
###Debug: disable uboot autoload of Cape
#disable_uboot_overlay_addr0=1
#disable_uboot_overlay_addr1=1
#disable_uboot_overlay_addr2=1
#disable_uboot_overlay_addr3=1
###
###U-Boot fdt tweaks... (60000 = 384KB)
#uboot_fdt_buffer=0x60000
###U-Boot Overlays###
cmdline=coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet
#In the event of edid real failures, uncomment this next line:
#cmdline=coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet video=HDMI-A-1:1024x768@60e
##enable Generic eMMC Flasher:
#cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh
I have two peripherals connected to the board, a wind sensor on UART1 and a modem on UART5.
I have configured the pins with these commands:
# Wind sensor
$ config-pin P9.24 uart # UART1 TX (not connected)
Current mode for P9_24 is: uart
$ config-pin P9.26 uart # UART1 RX
Current mode for P9_26 is: uart
$ config-pin P8.17 gpio_pu # Enable the sensor
Current mode for P8_17 is: gpio_pu
$ stty -F /dev/ttyS1 sane # Configure the serial link
$ stty -F /dev/ttyS # Check the state
speed 9600 baud; line = 0;
# Modem
$ config-pin P8.37 uart # UART5 TX
Current mode for P8_37 is: uart
$ config-pin P8.38 uart # UART5 RX
Current mode for P8_38 is: uart
$ config-pin P8.15 gpio_pu # Enable the modem
Current mode for P8_15 is: gpio_pu
$ stty -F /dev/ttyS5 sane # Configure the serial link
$ stty -F /dev/ttyS5
speed 9600 baud; line = 0;
The output of show-pins.pl looks fine for me:
$ sudo /opt/scripts/device/bone/show-pins.pl
P8.25 / eMMC d0 0 U7 fast rx up 1 mmc 1 d0 mmc@481d8000 (pinmux_emmc_pins)
P8.24 / eMMC d1 1 V7 fast rx up 1 mmc 1 d1 mmc@481d8000 (pinmux_emmc_pins)
P8.05 / eMMC d2 2 R8 fast rx up 1 mmc 1 d2 mmc@481d8000 (pinmux_emmc_pins)
P8.06 / eMMC d3 3 T8 fast rx up 1 mmc 1 d3 mmc@481d8000 (pinmux_emmc_pins)
P8.23 / eMMC d4 4 U8 fast rx up 1 mmc 1 d4 mmc@481d8000 (pinmux_emmc_pins)
P8.22 / eMMC d5 5 V8 fast rx up 1 mmc 1 d5 mmc@481d8000 (pinmux_emmc_pins)
P8.03 / eMMC d6 6 R9 fast rx up 1 mmc 1 d6 mmc@481d8000 (pinmux_emmc_pins)
P8.04 / eMMC d7 7 T9 fast rx up 1 mmc 1 d7 mmc@481d8000 (pinmux_emmc_pins)
P8.19 8 U10 fast rx down 7 gpio 0.22 ocp/P8_19_pinmux (pinmux_P8_19_default_pin)
P8.13 9 T10 fast rx down 7 gpio 0.23 ocp/P8_13_pinmux (pinmux_P8_13_default_pin)
P8.14 10 T11 fast rx down 7 gpio 0.26 ocp/P8_14_pinmux (pinmux_P8_14_default_pin)
P8.17 11 U12 fast rx up 7 gpio 0.27 ocp/P8_17_pinmux (pinmux_P8_17_gpio_pu_pin)
P8.12 12 T12 fast rx down 7 gpio 1.12 ocp/P8_12_pinmux (pinmux_P8_12_default_pin)
P8.11 13 R12 fast rx down 7 gpio 1.13 ocp/P8_11_pinmux (pinmux_P8_11_default_pin)
P8.16 14 V13 fast rx down 7 gpio 1.14 ocp/P8_16_pinmux (pinmux_P8_16_default_pin)
P8.15 15 U13 fast rx up 7 gpio 1.15 ocp/P8_15_pinmux (pinmux_P8_15_gpio_pu_pin)
P9.15 16 R13 fast rx down 7 gpio 1.16 ocp/P9_15_pinmux (pinmux_P9_15_default_pin)
P9.23 17 V14 fast rx down 7 gpio 1.17 ocp/P9_23_pinmux (pinmux_P9_23_default_pin)
P9.14 18 U14 fast rx down 7 gpio 1.18 ocp/P9_14_pinmux (pinmux_P9_14_default_pin)
P9.16 19 T14 fast rx down 7 gpio 1.19 ocp/P9_16_pinmux (pinmux_P9_16_default_pin)
P9.11 28 T17 fast rx up 7 gpio 0.30 ocp/P9_11_pinmux (pinmux_P9_11_default_pin)
P9.13 29 U17 fast rx up 7 gpio 0.31 ocp/P9_13_pinmux (pinmux_P9_13_default_pin)
P9.12 30 U18 fast rx up 7 gpio 1.28 ocp/P9_12_pinmux (pinmux_P9_12_default_pin)
P8.26 31 V6 fast rx up 7 gpio 1.29 ocp/P8_26_pinmux (pinmux_P8_26_default_pin)
P8.21 / eMMC clk 32 U9 fast rx up 2 mmc 1 clk mmc@481d8000 (pinmux_emmc_pins)
P8.20 / eMMC cmd 33 V9 fast rx up 2 mmc 1 cmd mmc@481d8000 (pinmux_emmc_pins)
P9.15 34 T13 fast rx up 7 gpio 2.00
P8.18 35 V12 fast rx down 7 gpio 2.01 ocp/P8_18_pinmux (pinmux_P8_18_default_pin)
P8.07 36 R7 fast rx up 7 gpio 2.02 ocp/P8_07_pinmux (pinmux_P8_07_default_pin)
P8.08 37 T7 fast rx up 7 gpio 2.03 ocp/P8_08_pinmux (pinmux_P8_08_default_pin)
P8.10 38 U6 fast rx up 7 gpio 2.04 ocp/P8_10_pinmux (pinmux_P8_10_default_pin)
P8.09 39 T6 fast rx up 7 gpio 2.05 ocp/P8_09_pinmux (pinmux_P8_09_default_pin)
P8.45 / hdmi / sysboot 0 40 R1 fast rx down 7 gpio 2.06 ocp/P8_45_pinmux (pinmux_P8_45_default_pin)
P8.46 / hdmi / sysboot 1 41 R2 fast rx down 7 gpio 2.07 ocp/P8_46_pinmux (pinmux_P8_46_default_pin)
P8.43 / hdmi / sysboot 2 42 R3 fast rx down 7 gpio 2.08 ocp/P8_43_pinmux (pinmux_P8_43_default_pin)
P8.44 / hdmi / sysboot 3 43 R4 fast rx down 7 gpio 2.09 ocp/P8_44_pinmux (pinmux_P8_44_default_pin)
P8.41 / hdmi / sysboot 4 44 T1 fast rx down 7 gpio 2.10 ocp/P8_41_pinmux (pinmux_P8_41_default_pin)
P8.42 / hdmi / sysboot 5 45 T2 fast rx down 7 gpio 2.11 ocp/P8_42_pinmux (pinmux_P8_42_default_pin)
P8.39 / hdmi / sysboot 6 46 T3 fast rx down 7 gpio 2.12 ocp/P8_39_pinmux (pinmux_P8_39_default_pin)
P8.40 / hdmi / sysboot 7 47 T4 fast rx down 7 gpio 2.13 ocp/P8_40_pinmux (pinmux_P8_40_default_pin)
P8.37 / hdmi / sysboot 8 48 U1 fast rx up 4 uart 5 txd ocp/P8_37_pinmux (pinmux_P8_37_uart_pin)
P8.38 / hdmi / sysboot 9 49 U2 fast rx up 4 uart 5 rxd ocp/P8_38_pinmux (pinmux_P8_38_uart_pin)
P8.36 / hdmi / sysboot 10 50 U3 fast rx down 7 gpio 2.16 ocp/P8_36_pinmux (pinmux_P8_36_default_pin)
P8.34 / hdmi / sysboot 11 51 U4 fast rx down 7 gpio 2.17 ocp/P8_34_pinmux (pinmux_P8_34_default_pin)
P8.35 / hdmi / sysboot 12 52 V2 fast rx down 7 gpio 0.08 ocp/P8_35_pinmux (pinmux_P8_35_default_pin)
P8.33 / hdmi / sysboot 13 53 V3 fast rx down 7 gpio 0.09 ocp/P8_33_pinmux (pinmux_P8_33_default_pin)
P8.31 / hdmi / sysboot 14 54 V4 fast rx down 7 gpio 0.10 ocp/P8_31_pinmux (pinmux_P8_31_default_pin)
P8.32 / hdmi / sysboot 15 55 T5 fast rx down 7 gpio 0.11 ocp/P8_32_pinmux (pinmux_P8_32_default_pin)
P8.27 / hdmi 56 U5 fast rx down 7 gpio 2.22 ocp/P8_27_pinmux (pinmux_P8_27_default_pin)
P8.29 / hdmi 57 R5 fast rx down 7 gpio 2.23 ocp/P8_29_pinmux (pinmux_P8_29_default_pin)
P8.28 / hdmi 58 V5 fast rx down 7 gpio 2.24 ocp/P8_28_pinmux (pinmux_P8_28_default_pin)
P8.30 / hdmi 59 R6 fast rx down 7 gpio 2.25 ocp/P8_30_pinmux (pinmux_P8_30_default_pin)
P9.22 / spi boot clk 84 A17 fast rx up 7 gpio 0.02 ocp/P9_22_pinmux (pinmux_P9_22_default_pin)
P9.21 / spi boot in 85 B17 fast rx up 7 gpio 0.03 ocp/P9_21_pinmux (pinmux_P9_21_default_pin)
P9.18 / spi boot out 86 B16 fast rx up 7 gpio 0.04 ocp/P9_18_pinmux (pinmux_P9_18_default_pin)
P9.17 / spi boot cs 87 A16 fast rx up 7 gpio 0.05 ocp/P9_17_pinmux (pinmux_P9_17_default_pin)
P9.42a 89 C18 fast rx down 7 gpio 0.07 ocp/P9_42_pinmux (pinmux_P9_42_default_pin)
P9.20 / cape i²c sda 94 D18 fast rx up 3 i²c 2 sda ocp/P9_20_pinmux (pinmux_P9_20_default_pin)
P9.19 / cape i²c scl 95 D17 fast rx up 3 i²c 2 scl ocp/P9_19_pinmux (pinmux_P9_19_default_pin)
P9.26 96 D16 fast rx up 0 uart 1 rxd ocp/P9_26_pinmux (pinmux_P9_26_uart_pin)
P9.24 97 D15 fast rx up 0 uart 1 txd ocp/P9_24_pinmux (pinmux_P9_24_uart_pin)
P9.31 / hdmi audio clk 100 A13 fast rx down 7 gpio 3.14 ocp/P9_31_pinmux (pinmux_P9_31_default_pin)
P9.29 / hdmi audio fs 101 B13 fast rx down 7 gpio 3.15 ocp/P9_29_pinmux (pinmux_P9_29_default_pin)
P9.30 102 D12 fast rx down 7 gpio 3.16 ocp/P9_30_pinmux (pinmux_P9_30_default_pin)
P9.28 / hdmi audio data 103 C12 fast rx down 7 gpio 3.17 ocp/P9_28_pinmux (pinmux_P9_28_default_pin)
P9.42b 104 B12 fast rx down 7 gpio 3.18 ocp/P9_92_pinmux (pinmux_P9_92_default_pin)
P9.27 105 C13 fast rx down 7 gpio 3.19 ocp/P9_27_pinmux (pinmux_P9_27_default_pin)
P9.41 106 D13 fast rx down 7 gpio 3.20 ocp/P9_91_pinmux (pinmux_P9_91_default_pin)
P9.25 / audio osc 107 A14 fast rx down 7 gpio 3.21 ocp/P9_25_pinmux (pinmux_P9_25_default_pin)
P9.41 / jtag emu3 109 D14 fast rx down 7 gpio 0.20 ocp/P9_41_pinmux (pinmux_P9_41_default_pin)
But when I use screen/picocom/minicom/cat/whatever on /dev/ttyS1 or /dev/ttyS5, nothing happens.
E.g.:
# Expected output
$ cat /dev/ttyS1
PLCJ,5EFF,5DFF,2F,3434,4241
PLCJE84C8,6DAE,32,C,021.0,C,,*51
PLCJ,5EFF,5CFE,2F,3434,4241
<snip>
# Current output
$ cat /dev/ttyS1
<nothing>
What did I miss?
