Hi dear developers,
I am using Jetson Xavier NX Developer Kit with the following Jetpack version:
nvidia-l4t-core 32.6.1-20210726122859
# R32 (release), REVISION: 6.1, GCID: 27863751, BOARD: t186ref, EABI: aarch64, DATE: Mon Jul 26 19:36:31 UTC 2021
I am facing a problem using the UART from pins 8 and 10 (BOARD mode). My setup is very simple: I am trying a loopback for self test. I used a jumper to connect those two pins. But still there is no connection (e.g. minicom is offline on all ports of available ls /dev/ttyTHS* ).
I’ve noticed something strange. When I run sudo /opt/nvidia/jetson-io/config-by-function.py -l all, I get:
Header 1 [default]: Jetson 40pin Header
Supported functions (pins):
- aud_mclk (7)
- dmic4 (35,38)
- dspk0 (12,40)
- dspk1 (35,38)
- extperiph3_clk (29)
- extperiph4_clk (31)
- i2s5 (12,35,38,40)
- pwm1 (33)
- pwm4 (15)
- pwm8 (32)
- spi1 (19,21,23,24,26)
- spi3 (13,16,18,22,37)
- uarta-cts/rts (11,36)
Header 2: Jetson Nano CSI Connector
No functions are supported.
Header 3: Jetson M.2 Key E Slot
Supported functions (pins): - dmic1 (8,14)
- dmic2 (10,12)
- i2s3 (8,10,12,14)
Pins 8 and 10 are only available in header 3 despite that they are not enabled there.
sudo /opt/nvidia/jetson-io/config-by-function.py -l enabled
I get:
Header 1 [default]: Jetson 40pin Header
Enabled functions (pins):
- pwm1 (33)
- pwm8 (32)
- spi1 (19,21,23,24,26)
- spi3 (13,16,18,22,37)
Header 2: Jetson Nano CSI Connector
No functions are enabled.
Header 3: Jetson M.2 Key E Slot
No functions are enabled.
And by running sudo /opt/nvidia/jetson-io/jetson-io.py, I do not see UART function corresponding to pins 8 and 10 to enable it (see attached).
I even tried to overlay the device tree by creating a custom.dtb and point to it in extline.config, but with no success.
the content of the custom dtb is:
/dts-v1/;
/plugin/;
/ {
compatible = "nvidia,p3509-0000+p3668-0000", "nvidia,jetson-xavier-nx", "nvidia,tegra194";
fragment@0 {
target = <&tegra_main_gpio>;
__overlay__ {
gpio14 {
nvidia,pins = "gpio14";
nvidia,function = "gpio";
nvidia,pull = <0>; /* 0: no pull, 1: pull-down, 2: pull-up */
nvidia,tristate = <1>; /* 0: enable, 1: disable */
nvidia,enable-input = <1>;
};
gpio15 {
nvidia,pins = "gpio15";
nvidia,function = "gpio";
nvidia,pull = <0>; /* 0: no pull, 1: pull-down, 2: pull-up */
nvidia,tristate = <1>; /* 0: enable, 1: disable */
nvidia,enable-input = <1>;
};
};
};
};
and I added fdtdir /boot/dtb/ fdt custom_uart810_pinmux.dtb to the end of APPEND in extlinux.config
I do not think that is normal. Why can I not use the uart as supposed? I will appreciate any guidance to help me fix this issue.
