Long Write from central SD130 and SDK11

Question

How to send more than 20 bytes from central to peripheral ?

Jackxl · Accepted Answer

Solution is long write and this is example of necessary part:

void on_ble_evt(ble_evt_t * p_ble_evt)
    {

case BLE_EVT_USER_MEM_REQUEST:          
            mem_block.len = QUEUED_WRITE_BUFFER_SIZE;
            mem_block.p_mem = &queued_write_buffer[0];
            err_code = sd_ble_user_mem_reply(m_deufol.conn_handle, &mem_block);
						//simple_uart_putstring("User mem request \r\n");
            break;
        
        case BLE_EVT_USER_MEM_RELEASE:
						
            if ((p_ble_evt->evt.common_evt.params.user_mem_release.mem_block.p_mem == mem_block.p_mem)&&(p_ble_evt->evt.common_evt.params.user_mem_release.mem_block.len == mem_block.len))
            {
                //memory released do nothing. 
								//simple_uart_putstring("User mem released \r\n");
            }
						break;
case BLE_GATTC_EVT_WRITE_RSP:
					if(m_deufol.conn_handle != BLE_CONN_HANDLE_INVALID)
					{
						uint8_t temp_data[BYTE_NUMBER];						
						if(p_ble_evt->evt.gattc_evt.params.write_rsp.handle == m_deufol.char_identification.handle 
								&& m_deufol.char_identification.uuid.uuid == BLE_DEUFOL_COMMON_CHAR_UUID)
						{
							if(p_ble_evt->evt.gattc_evt.gatt_status == BLE_GATT_STATUS_ATTERR_PREPARE_QUEUE_FULL)
							{
								ble_gattc_write_params_t write_params;	
								write_params.handle = m_deufol.common_handles.value_handle;
								write_params.len = 0;
								write_params.write_op = BLE_GATT_OP_EXEC_WRITE_REQ;
								write_params.offset = 0;
								write_params.flags = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE;
								write_params.p_value = NULL;
								err_code = sd_ble_gattc_write(m_deufol.conn_handle, &write_params);
								rsp_counter = 0;
							}
							else
							{
								if(p_ble_evt->evt.gattc_evt.params.write_rsp.write_op == BLE_GATT_OP_PREP_WRITE_REQ)
								{								
									rsp_counter++;
									if(p_ble_evt->evt.gattc_evt.gatt_status != BLE_GATT_STATUS_ATTERR_PREPARE_QUEUE_FULL)
									{									
										ble_gattc_write_params_t write_params;	
										write_params.handle = m_deufol.common_handles.value_handle;
										write_params.len = BYTE_NUMBER;								
										write_params.write_op = BLE_GATT_OP_PREP_WRITE_REQ;
										write_params.offset = rsp_counter * BYTE_NUMBER;
										write_params.flags = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE;
										for(uint8_t index = 0;index < BYTE_NUMBER;index++)
											temp_data[index] = write_array[rsp_counter * BYTE_NUMBER + index];
										write_params.p_value = temp_data;
										err_code = sd_ble_gattc_write(m_deufol.conn_handle, &write_params);
										
									}	
								}
							}
						}
					}
					break;
}

call this function first:

uint32_t send_data(ble_deufol_t * p_deufol,uint16_t length,uint8_t * write_array)
{	
	uint8_t temp_data[BYTE_NUMBER];
	for(uint8_t a = 0;a<BYTE_NUMBER;a++)
		temp_data[a] = write_array[a];
	ble_gattc_write_params_t write_params;	
	write_params.handle = p_deufol->common_handles.value_handle;
	write_params.len = length;
	write_params.write_op = BLE_GATT_OP_PREP_WRITE_REQ;
	write_params.offset = 0;
	write_params.flags = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE;
	write_params.p_value = data;
	err_code = sd_ble_gattc_write(p_deufol->conn_handle, &write_params);
	return err_code;
}

Count of sending data is depend on QUEUED_WRITE_BUFFER_SIZE. This value has to be larger than sending data. BYTE_NUMBER = 18

Long Write from central SD130 and SDK11

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