libmodbus移植

发布于 2023-04-23 08:50:36 浏览：555 订阅该版

小白，今天移植libmodbus，用的是env和keil,rtt的版本是4.0.5。移植时发面主机发送正常，但没接收？请大佬们指点一下！
![1234.png](https://oss-club.rt-thread.org/uploads/20230423/1548b73d8c65503cca1407cb2d44490c.png.webp)
![123.png](https://oss-club.rt-thread.org/uploads/20230423/f3d9b8d6ae1de03017229a9f52e70d89.png.webp)

```c
#include "stdio.h"
#include "string.h"

#define RS485_RE GET_PIN(B, 1)

static void test_thread(void *param)
{
	 rt_pin_mode(RS485_RE, PIN_MODE_OUTPUT);
    uint16_t tab_reg[64] = {0};
    modbus_t *ctx = RT_NULL;
    ctx = modbus_new_rtu("/dev/uart3", 115200, 'N', 8, 1);
    modbus_rtu_set_serial_mode(ctx, MODBUS_RTU_RS485);
    modbus_rtu_set_rts(ctx, RS485_RE, MODBUS_RTU_RTS_UP);
    modbus_set_slave(ctx, 1);
    modbus_connect(ctx);
    modbus_set_response_timeout(ctx, 0, 1000000);
    int num = 0;
    while (1)
    {
        memset(tab_reg, 0, 64 * 2);
        int regs = modbus_read_registers(ctx, 1, 10, tab_reg);
        printf("-------------------------------------------\n");
        printf("[%4d][read num = %d]", num, regs);
        num++;
        int i;
        for (i = 0; i < 20; i++)
        {
            printf("<%#x>", tab_reg[i]);
        }
        printf("\n");
        printf("-------------------------------------------\n");
        rt_thread_mdelay(5000);
    }
    //7-关闭modbus端口
    modbus_close(ctx);

//8-释放modbus资源
    modbus_free(ctx);
}

static int rtu_test_init(void)
{
    rt_pin_mode(RS485_RE, PIN_MODE_OUTPUT);
    rt_thread_t tid;
    tid = rt_thread_create("test",
                           test_thread, RT_NULL,
                           2048,
                           12, 10);
    if (tid != RT_NULL)
        rt_thread_startup(tid);
    return RT_EOK;
}
INIT_APP_EXPORT(rtu_test_init);
```