onenet GPS的经纬

rt-thread如何上传GPS的经纬度到onenet?

发布于 2020-08-16 14:56:41 浏览：1018 订阅该版

3 个回答

921742079 2020-08-16

这家伙很懒，什么也没写！

KJUS_6193 2020-08-16

这家伙很懒，什么也没写！

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KJUS_6193 2020-08-16

这家伙很懒，什么也没写！

改装了两个函数
```
 rt_err_t onenet_mqtt_get_string_gpsDIY( char* lat,char* lon,char **out_buff, size_t *length)
{
    rt_err_t result = RT_EOK;
    cJSON *root = RT_NULL;
    cJSON *pvalue = RT_NULL;
    char *msg_str = RT_NULL;

/* RT_ASSERT(ds_name);
    RT_ASSERT(str);*/
    RT_ASSERT(out_buff);
    RT_ASSERT(length);

root = cJSON_CreateObject();
    pvalue = cJSON_CreateObject();
    if (!root)
    {
        LOG_E("MQTT publish string data failed! cJSON create object error return NULL!");
        return -RT_ENOMEM;
    }

cJSON_AddStringToObject(pvalue, "lat", lat);
    cJSON_AddStringToObject(pvalue, "lon", lon);
    cJSON_AddItemToObject(root,"loc",pvalue);
    /* render a cJSON structure to buffer */
    msg_str = cJSON_PrintUnformatted(root);
    if (!msg_str)
    {
        LOG_E("MQTT publish string data failed! cJSON print unformatted error return NULL!");
        result = -RT_ENOMEM;
        goto __exit;
    }

*out_buff = ONENET_MALLOC(strlen(msg_str) + 3);
    if (!(*out_buff))
    {
        LOG_E("ONENET mqtt upload string data failed! No memory for send buffer!");
        return -RT_ENOMEM;
    }

strncpy(&(*out_buff)[3], msg_str, strlen(msg_str));
    *length = strlen(&(*out_buff)[3]);

/* mqtt head and json length */
    (*out_buff)[0] = 0x03;
    (*out_buff)[1] = (*length & 0xff00) >> 8;
    (*out_buff)[2] = *length & 0xff;
    *length += 3;

__exit:
    if (root)
    {
        cJSON_Delete(root);
    }
    if (msg_str)
    {
        cJSON_free(msg_str);
    }

return result;
}

/**
 * upload string data to OneNET cloud.
 *
 * @param   ds_name     datastream name
 * @param   str         string data
 *
 * @return  0 : upload digit data success
 *         -5 : no memory
 */
rt_err_t onenet_mqtt_upload_GPSDIY(char* lat,char* lon)
{
    char *send_buffer = RT_NULL;
    rt_err_t result = RT_EOK;
    size_t length = 0;

result = onenet_mqtt_get_string_gpsDIY(lat,lon,&send_buffer, &length);
    if (result < 0)
    {
        goto __exit;
    }

result = onenet_mqtt_publish(ONENET_TOPIC_DP, (uint8_t *) send_buffer, length);
    if (result < 0)
    {
        LOG_E("onenet publish failed (%d)!", result);
        goto __exit;
    }

__exit: if (send_buffer)
    {
        ONENET_FREE(send_buffer);
    }

return result;
}

```
然后在发送线程里调用
```
onenet_mqtt_upload_GPSDIY(info->coord.location.longitude.string,info->coord.location.latitude.string)
```
OK