mynewt 学习三： bleprph UUID服务属性修改(数据回传)

 

本文主要记录bleprph工程的修改，目的是让其在收到APP端发送的数据后能回传回去

 

 原始工程gatt_svr.c里面有个服务“59462f12-9543-9999-12c8-58b459a2712d”，有两个特性通道“5c3a659e-897e-45e1-b016-007107c96df6”和“5c3a659e-897e-45e1-b016-007107c96df7”, 其默认是配置如下

static const struct ble_gatt_svc_def gatt_svr_svcs[] = {
    {
        /*** Service: Security test. */
        .type = BLE_GATT_SVC_TYPE_PRIMARY,
        .uuid = &gatt_svr_svc_sec_test_uuid.u,
        .characteristics = (struct ble_gatt_chr_def[]) { {
            /*** Characteristic: Random number generator. */
            .uuid = &gatt_svr_chr_sec_test_rand_uuid.u,
            .access_cb = gatt_svr_chr_access_sec_test,
            .flags = BLE_GATT_CHR_F_READ | BLE_GATT_CHR_F_READ_ENC,
        }, {
            /*** Characteristic: Static value. */
            .uuid = &gatt_svr_chr_sec_test_static_uuid.u,
            .access_cb = gatt_svr_chr_access_sec_test,
            .flags = BLE_GATT_CHR_F_READ |
                     BLE_GATT_CHR_F_WRITE | BLE_GATT_CHR_F_WRITE_ENC,
        }, {
            0, /* No more characteristics in this service. */
        } },
    },

    {
        0, /* No more services. */
    },
};

 

上面在APP发端数据时会弹出一个授权配对的对话框，其主要是原因是上面.flags使用了  ‘LE_GATT_CHR_F_WRITE_ENC’ 这个属性。现将属性修改如 下：一个通道负责收数据，另一通道负责发数据，同时去掉须授权

uint16_t gatt_svr_val_handle;

static const struct ble_gatt_svc_def gatt_svr_svcs[] = {
    {
        /*** Service: Security test. */
        .type = BLE_GATT_SVC_TYPE_PRIMARY,
        .uuid = &gatt_svr_svc_sec_test_uuid.u,
        .characteristics = (struct ble_gatt_chr_def[]) { {
            /*** Characteristic: Random number generator. */
            .uuid = &gatt_svr_chr_sec_test_rand_uuid.u,
            .access_cb = gatt_svr_chr_access_sec_test,
            .flags = BLE_GATT_CHR_F_NOTIFY,//BLE_GATT_CHR_F_READ ,| BLE_GATT_CHR_F_READ_ENC,
            .val_handle = &gatt_svr_val_handle,
        }, {
            /*** Characteristic: Static value. */
            .uuid = &gatt_svr_chr_sec_test_static_uuid.u,
            .access_cb = gatt_svr_chr_access_sec_test,
            .flags = BLE_GATT_CHR_F_WRITE_NO_RSP,//BLE_GATT_CHR_F_READ |
                     //BLE_GATT_CHR_F_WRITE, | BLE_GATT_CHR_F_WRITE_ENC,
        }, {
            0, /* No more characteristics in this service. */
        } },
    },

    {
        0, /* No more services. */
    },
};

 

注释掉函数gatt_svr_chr_write，主要是编译出错说此函数定义了但未使用。其次是对 gatt_svr_chr_access_sec_test 修改让其在收到数据后回传出去

/*
static int
gatt_svr_chr_write(struct os_mbuf *om, uint16_t min_len, uint16_t max_len,
                   void *dst, uint16_t *len)
{
    uint16_t om_len;
    int rc;

    om_len = OS_MBUF_PKTLEN(om);
    if (om_len < min_len || om_len > max_len) {
        return BLE_ATT_ERR_INVALID_ATTR_VALUE_LEN;
    }

    rc = ble_hs_mbuf_to_flat(om, dst, max_len, len);
    if (rc != 0) {
        return BLE_ATT_ERR_UNLIKELY;
    }

    return 0;
}
*/


static int
gatt_svr_chr_access_sec_test(uint16_t conn_handle, uint16_t attr_handle,
                             struct ble_gatt_access_ctxt *ctxt,
                             void *arg)
{
    const ble_uuid_t *uuid;
    int rc;

    uuid = ctxt->chr->uuid;

    /* Determine which characteristic is being accessed by examining its
     * 128-bit UUID.
     */
    if (ble_uuid_cmp(uuid, &gatt_svr_chr_sec_test_static_uuid.u) == 0) {
        switch (ctxt->op) {
        case BLE_GATT_ACCESS_OP_READ_CHR:
            rc = os_mbuf_append(ctxt->om, &gatt_svr_sec_test_static_val,
                                sizeof gatt_svr_sec_test_static_val);
            return rc == 0 ? 0 : BLE_ATT_ERR_INSUFFICIENT_RES;

        case BLE_GATT_ACCESS_OP_WRITE_CHR:
              {
                   struct os_mbuf *txom;

                 txom = ble_hs_mbuf_from_flat(ctxt->om->om_data, ctxt->om->om_len);
                 if (!txom) {
                    return 0;
                 }
                         
                 rc = ble_gattc_notify_custom(conn_handle, gatt_svr_val_handle, txom);
              }return rc;

        default:
            assert(0);
            return BLE_ATT_ERR_UNLIKELY;
        }
    }

    /* Unknown characteristic; the nimble stack should not have called this
     * function.
     */
    assert(0);
    return BLE_ATT_ERR_UNLIKELY;
}

 

最后使用bluelight 应用测试其功能如下：

         

 

 

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