How to receive data in the correct format when sending data to the app_timer

[lyrics]

Hi, all

I'm using nRF52832 pca10040, s132.

Like 'ble_app_hrs' example, I changed the 'ble_app_uart' example to send data using app_timer.

In the example of 'hrs', they changed Hexa to Decimal using 'hrm_encode'. Am I right?

But what I want is.. when I send decimal data, I want 'uart_c' to receive the same decimal data.

'uart_c' successfully receive data but cannot read correctly.

I want to know why.

And I also want to understand things like situations that are transformed in the process of sending and receiving data.

This is uart example. (I added)

uint8_t           heart_rate;

heart_rate = 123;
len = sizeof(heart_rate);

memset(&hvx_params, 0, sizeof(hvx_params));

hvx_params.handle = p_nus->tx_handles.value_handle;
hvx_params.type   = BLE_GATT_HVX_NOTIFICATION;
hvx_params.offset = 0;
hvx_params.p_len  = len;
hvx_params.p_data = heart_rate;

err_code = sd_ble_gatts_hvx(conn_handle, &hvx_params);

and I edited 'uart_c' example like this..

static void ble_nus_chars_received_uart_print(uint8_t * p_data, uint16_t data_len)
{
    ret_code_t ret_val;

    NRF_LOG_DEBUG("Receiving data.");
    NRF_LOG_HEXDUMP_DEBUG(p_data, data_len);

    for (uint32_t i = 0; i < data_len; i++)
    {
          printf("%d\r\n", p_data[i]);
//        do
//        {
//            ret_val = app_uart_put(p_data[i]);
//            if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
//            {
//                NRF_LOG_ERROR("app_uart_put failed for index 0x%04x.", i);
//                APP_ERROR_CHECK(ret_val);
//            }
//        } while (ret_val == NRF_ERROR_BUSY);
    }
    
    ....
    
}

This is result.

( I think this is how it should be done. )

tx_evt

1

2

3 

0

Best Regards,

lyrics

[lyrics]

I understand.. There is only one connection handle.. 0x0. (ble_app_uart_c)

Henry_Chou said:

I think the data would be the same as the TX event.  

Does this mean that the central should modify the data encode of the TX side?
If correct, I modified the ' ble_nus_chars_received_uart_print ' function of uart_c.

Just like this..

 for (uint32_t i = 0; i < data_len; i++)
    {
          printf("%d \r\n", p_data[i]);
//        do
//        {
//            ret_val = app_uart_put(p_data[i]);
//            if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
//            {
//                NRF_LOG_ERROR("app_uart_put failed for index 0x%04x.", i);
//                APP_ERROR_CHECK(ret_val);
//            }
//        } while (ret_val == NRF_ERROR_BUSY);
    }

Or maybe I'm wrong to make this change.

Thank you in advance. :)

[Vidar Berg]

Hello,

I don't see any data being passed to ble_nus_data_send_s(), only the service structure and connection handle. Can you post your implementation of this function as well?

[lyrics]

sorry for late reply..

Is this right what you said,,?

static void data_level_meas_timeout_handler(void * p_context)
{
    static uint32_t cnt = 0;
    ret_code_t      err_code;

    UNUSED_PARAMETER(p_context);

    cnt++;
    err_code = ble_nus_data_send_s(&m_nus, m_conn_handle);
    
    ...
}

uint32_t ble_nus_data_send_s(ble_nus_t * p_nus, uint16_t conn_handle)
{
    uint32_t err_code;
    ble_gatts_hvx_params_t     hvx_params;
    // Send value if connected and notifying
    if (conn_handle != BLE_CONN_HANDLE_INVALID)
    {
        uint8_t          len;
        uint16_t         heart_rate;

        heart_rate = 123;
        len = sizeof(heart_rate);
        
        memset(&hvx_params, 0, sizeof(hvx_params));

        hvx_params.handle = p_nus->tx_handles.value_handle;
        hvx_params.type   = BLE_GATT_HVX_NOTIFICATION;
        hvx_params.offset = 0;
        hvx_params.p_len  = len;
        hvx_params.p_data = heart_rate;


        err_code = sd_ble_gatts_hvx(conn_handle, &hvx_params);
        return err_code;
    }
}

[lyrics]

I solved this problem using hrm_encode function... :)