Interface
本节介绍 NG4500系列设备常用接口（GPIO/I2C/SPI/CAN/USB/UART）的驱动与控制方法，重 点说明硬件资源分配、典型应用场景及基础操作指令。
GPIO
详细引脚分配参考官方文档：：Jetson Orin NX Series and Jetson Orin Nano Series Pinmux
- IO 扩展面板接口分配如下：
| Pin # | Signal Name | Description | Direction | Pin Type |
|---|---|---|---|---|
| 218 | GPIO12 | GPIO=Low/high when IN1=high（Open）/low(Short) | Input | dry contact |
| IN1_COM: COM pin | ||||
| 216 | GPIO11 | IN2: GPIO=Low/high when IN1=high（Open）/low(Short) | Input | dry contact |
| IN2_COM: COM pin | ||||
| 206 | GPIO07 | IN3: GPIO=Low/high when IN1=high（Open）/low(Short) | Input | dry contact |
| IN3_COM: COM pin | ||||
| 228 | GPIO13 | IN4: GPIO=Low/high when IN1=high（Open）/low(Short) | Input | dry contact |
| IN4_COM: COM pin | ||||
| 199 | I2S0_SCLK_1V8 | OUT1: GPIO=Low for short, high for open | Output | dry contact |
| OUT1_COM: COM pin | ||||
| 197 | I2S0_LRCK_1V8 | OUT2: GPIO=Low for short, high for open | Output | dry contact |
| OUT2_COM: COM pin | ||||
| 195 | I2S0_SDIN_1V8 | OUT3: GPIO=Low for shor, high for open. | Output | dry contact |
| OUT3_COM: COM pin | ||||
| 193 | I2S0_SDOUT_1V8 | OUT4: GPIO=Low for short, high for open. | Output | dry contact |
| OUT4_COM: COM pin |
软件操作方法
- 使用
gpioinfo查询 GPIO 映射关系和状态：
- 使用
gpioset控制 GPIO 输出：
# To set GPIO12 to HIGH
sudo gpioset --mode=wait gpiochip0 144=1
# To set GPIO12 to LOW
sudo gpioset --mode=wait gpiochip0 144=0
UART
UART 实例与资源分配
| Usage on Orin nano/NX | UART Instance | Base Address | Ball Name | Bus Name | DTS status | DTS alias |
|---|---|---|---|---|---|---|
| Debug | UARTC | 0x0c280000 | UART2 | ttyTCU0 | OK | serial0 |
| RS485 | UARTA | 0x03100000 | UART1 | ttyTHS1 | OK | serial1 |
| RS232 | UARTB | 0x03110000 | UART0 | ttyTHS3 | OK | serial3 |
-
Debug 串口（ttyTCU0）
-
硬件连接：将 Debug 线连接至 PC。
-
串口参数：波特率 115200，数据位 8，停止位 1，无奇偶校验，无流控。
-
常用终端工具：Windows 下可用 PuTTY、Xshell，Linux 下可用 minicom、screen。
-
-
RS232 接口（ttyTHS3）
- 硬件接口定义
Pin Signal Name Description Direction Pin Type 99 UART0_TXD Use for uart Ransmit (with 3.3 level shifter) Output CMOS – 1.8V 101 UART0_RXD Use for uart Receive (with 3.3 level shifter) Input CMOS – 1.8V -
连接说明
- 使用接头1连接 PC，接头2连接 Jetson RS232 的 TX/RX。
- 确保电平转换正确，避免损坏硬件。
-
RS485 接口（ttyTHS1）
- 硬件接口定义
Pin Signal Name Description Direction Pin Type 203 UART1_TXD Use for RS_485 Output CMOS 1.8V 205 UART1_RXD Use for RS_485 Input CMOS 1.8V 207 UART1_RTS* RS_485 enable pin Output CMOS 1.8V - 依赖安装
sudo apt-get update
sudo apt-get install gpiod libgpiod-dev- 编译测试程序
gcc -o rs485_test rs485_test.c -lgpiod- 运行示例
sudo ./rs485_test [TTY_DIR] [DE_CHIP] [DE_LINE]
# 运行
sudo ./rs485_test /dev/ttyTHS1 /dev/gpiochip0 112- 功能说明
- 启动后输入
send切换到发送模式，输入内容后回车发送。 - 输入
recv切换到接收模式，显示串口接收内容。 - 输入
quit退出程序。
- 启动后输入
-
参考代码
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <gpiod.h>
#include <linux/serial.h>
#define BUFFER_SIZE 256
#define RS485_CONSUMER "RS485_program"
struct gpiod_chip *chip;
struct gpiod_line *rts_line;
void setup_gpio(char *gpio_chip, int gpio_line)
{
int ret;
chip = gpiod_chip_open(gpio_chip);
if (!chip) {
fprintf(stderr, "gpiod_chip_open");
exit(EXIT_FAILURE);
}
rts_line = gpiod_chip_get_line(chip, gpio_line);
if (!rts_line) {
fprintf(stderr, "Failed to get GPIO line %d\n", gpio_line);
gpiod_chip_close(chip);
exit(EXIT_FAILURE);
}
ret = gpiod_line_request_output(rts_line, RS485_CONSUMER, 0);
if (ret < 0) {
fprintf(stderr, "Failed to request GPIO line as output: %s\n", strerror(-ret));
gpiod_chip_close(chip);
exit(EXIT_FAILURE);
}
}
void set_rts_high() {
gpiod_line_set_value(rts_line, 1);
int value = gpiod_line_get_value(rts_line);
printf("RTS set to HIGH, actual value: %d\n", value);
}
void set_rts_low() {
gpiod_line_set_value(rts_line, 0);
int value = gpiod_line_get_value(rts_line);
printf("RTS set to LOW, actual value: %d\n", value);
}
int main(int argc, char* argv[]) {
int tty_fd;
char *tty_name;
struct termios tty;
char buffer[BUFFER_SIZE];
ssize_t n;
int ready;
fd_set readfds;
int rts_line_num;
char *gpio_chip;
int mode = 0;
if (argc < 4) {
printf("Usage: %s /dev/ttyTHS1 GPIO_CHIP(/dev/gpiochip*) RTS_LINE\n", argv[0]);
return 1;
}
tty_name = argv[1];
gpio_chip = argv[2];
rts_line_num = atoi(argv[3]);
setup_gpio(gpio_chip, rts_line_num);
tty_fd = open(tty_name, O_RDWR | O_NOCTTY | O_NDELAY);
if (tty_fd < 0) {
perror("Unable to open serial port");
return 1;
}
tcgetattr(tty_fd, &tty);
cfmakeraw(&tty);
cfsetispeed(&tty, B9600);
cfsetospeed(&tty, B9600);
tcsetattr(tty_fd, TCSANOW, &tty);
printf("Serial port %s opened successfully, fd: %d\n", tty_name, tty_fd);
while (1) {
FD_ZERO(&readfds);
FD_SET(tty_fd, &readfds);
FD_SET(STDIN_FILENO, &readfds);
ready = select(tty_fd + 1, &readfds, NULL, NULL, NULL);
if (ready == -1) {
perror("select");
break;
}
if (FD_ISSET(tty_fd, &readfds)) {
set_rts_low();
n = read(tty_fd, buffer, BUFFER_SIZE - 1);
if (n > 0) {
buffer[n] = '\0';
printf("Received: %s\n", buffer);
}
}
if (FD_ISSET(STDIN_FILENO, &readfds)) {
if (fgets(buffer, BUFFER_SIZE, stdin) != NULL) {
buffer[strcspn(buffer, "\n")] = '\0';
if (strcmp(buffer, "send") == 0) {
mode = 1;
printf("Switched to SEND mode\n");
continue;
} else if (strcmp(buffer, "recv") == 0) {
mode = 0;
printf("Switched to RECEIVE mode\n");
continue;
} else if (strcmp(buffer, "quit") == 0) {
break;
}
if (mode == 1) {
set_rts_high();
usleep(10000);
write(tty_fd, buffer, strlen(buffer));
tcdrain(tty_fd);
set_rts_low();
} else {
printf("Invalid command in RECEIVE mode\n");
}
}
}
}
close(tty_fd);
gpiod_line_release(rts_line);
gpiod_chip_close(chip);
return 0;
}
SPI
- 硬件接口分配
| Pin | Signal Name | Description | Direction | Pin Type |
|---|---|---|---|---|
| 106 | SPI1_SCK | SPI 1 Clock | Bidir | CMOS – 3.3V |
| 108 | SPI1_MISO | SPI 1 Master In / Slave Out | Bidir | CMOS – 3.3V |
| 104 | SPI1_MOSI | SPI 1 Master Out / Slave In | Bidir | CMOS – 3.3V |
| 110 | SPI1_CS0* | SPI 1 Chip Select 0 | Bidir | CMOS – 3.3V |
| 112 | SPI1_CS1* | SPI 1 Chip Select 1 | Bidir | CMOS – 3.3V |
-
硬件连接：短接
MOSI和MISO，用于回环测试。 -
SPI 使能与配置
-
运行指令，启动配置工具：
sudo python /opt/nvidia/jetson-io/jetson-io.py
-
选择
Configure Jetson 40pin Header -
选择
Configure header pins manually
-
按空格选择 SPI1 和 SPI3，启用 SPI
-
返回并选择
Save and reboot to reconfigure pins，重启后生效
-
-
测试方法，参考如下：
# 获取spi源码
git clone https://github.com/rm-hull/spidev-test
cd spidev-test/
gcc spidev_test.c -o spidev_test
# 测试
./spidev_test -v -D /dev/spidev0.0 -p "Test"
CAN
- 硬件接口分配
| Pin | Signal Name | Description | Direction | Pin Type |
|---|---|---|---|---|
| 145 | CAN_TX | FD CAN Transmit | Output | CMOS – 3.3V |
| 143 | CAN_RX | FD CAN Receive | Input | CMOS – 3.3V |
- 硬件连接：两台设备 CAN 的 D+ 对 D+，D- 对 D-。
软件安装与测试
- 安装
can-utils工具
sudo apt update
sudo apt-get install can-utils
- 测试方法，参考如下：
# 查看接口状态
ip link show can0
# 配置接口，设置波特率为 100kbps
sudo ip link set can0 up type can bitrate 100000
# 监听数据
candump can0
# 发送数据
cansend can0 123#11.22.33.44
RTC
基本使用操作
- 设置 RTC 时间
sudo hwclock --set --date="2000-01-01 12:00:00"
- 查询RTC时间
sudo hwclock -r
- 系统时间与 RTC 同步
# 系统时间 → RTC
sudo hwclock --systohc
# RTC → 系统时间
sudo hwclock --hctosys
- 查询系统时间
date
- 网络时钟同步
# 如无法设置RTC，需要确认是否打开了NTP服务
# 禁用NTP服务
sudo systemctl stop systemd-timesyncd.service
sudo timedatectl set-ntp false
Camera
-
启动和配置摄像头模块的方法，以
imx219为例，硬件连接如下：
-
通过config-by-hardware.py软件启动摄像头，重启后生效
# 列出当前支持的硬件模块
sudo python /opt/nvidia/jetson-io/config-by-hardware.py -l
#输出如下：
Header 1 [default]: Jetson 40pin Header
Available hardware modules:
1. Adafruit SPH0645LM4H
2. Adafruit UDA1334A
3. FE-PI Audio V1 and Z V2
4. ReSpeaker 4 Mic Array
5. ReSpeaker 4 Mic Linear Array
Header 2: Jetson 24pin CSI Connector
Available hardware modules:
1. Camera IMX219 Dual
2. Camera IMX219 Dual CamThink
3. Camera IMX219-A
4. Camera IMX219-A and IMX477-C
5. Camera IMX219-C
6. Camera IMX477 Dual
7. Camera IMX477 Dual 4 lane
8. Camera IMX477-A
9. Camera IMX477-A and IMX219-C
10. Camera IMX477-C
Header 3: Jetson M.2 Key E Slot
No hardware configurations found!
# 选择并配置 IMX219 Dual CamThink 摄像头模块。
# -n 选择Header编号，Camera IMX219 Dual CamThink 是dtbo的overlay-name
sudo python /opt/nvidia/jetson-io/config-by-hardware.py -n 2='Camera IMX219 Dual CamThink'
- 接入鼠标键盘，启动终端，运行以 下指令：
sudo apt update
sudo apt install -y nvidia-l4t-gstreamer nvidia-l4t-jetson-multimedia-api
# 启动摄像头
nvgstcapture-1.0