A simple program that uses the UARTService to transfer string data over GATT. Can be used with the nRF Toolbox app for rapid prototyping.

Dependencies:   BLE_API mbed nRF51822

Fork of UART_TEMPLATE by daniel veilleux

Revision:
0:442c7a6f1978
Child:
1:32c6991f7180
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Dec 15 21:05:18 2014 -0800
@@ -0,0 +1,193 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "BLEDevice.h"
+#include "UARTService.h"
+#include "nrf_temp.h"
+
+#define MAX_REPLY_LEN           (UARTService::BLE_UART_SERVICE_MAX_DATA_LEN)
+#define SENSOR_READ_INTERVAL_S  (0.5F) 
+#define ADV_INTERVAL_MS         (1000UL)
+#define UART_BAUD_RATE          (19200UL)
+#define DEVICE_NAME             ("DEMO SENSOR") // This can be read AFTER connecting to the device.
+#define SHORT_NAME              ("HACKDEMO")    // Keep this short: max 8 chars if a 128bit UUID is also advertised.
+
+#define DEBUG(...)              { m_serial_port.printf(__VA_ARGS__); }
+
+
+BLEDevice   m_ble;
+Serial      m_serial_port(p9, p11);  // TX pin, RX pin
+DigitalOut  m_cmd_led(LED1);
+DigitalOut  m_error_led(LED2);
+AnalogIn    m_analog_in(p1);
+uint16_t    m_analog_in_value;
+UARTService *m_uart_service_ptr;
+
+
+/**
+ * This callback is used whenever a disconnection occurs.
+ */
+void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
+{
+    switch (reason) {
+    case Gap::REMOTE_USER_TERMINATED_CONNECTION:
+        DEBUG("Disconnected (REMOTE_USER_TERMINATED_CONNECTION)\n\r");
+        break;
+    case Gap::LOCAL_HOST_TERMINATED_CONNECTION:
+        DEBUG("Disconnected (LOCAL_HOST_TERMINATED_CONNECTION)\n\r");
+        break;
+    case Gap::CONN_INTERVAL_UNACCEPTABLE:
+        DEBUG("Disconnected (CONN_INTERVAL_UNACCEPTABLE)\n\r");
+        break;
+    }
+
+    DEBUG("Restarting the advertising process\n\r");
+    m_ble.startAdvertising();
+}
+
+
+/**
+ * This callback is used whenever the host writes data to one of our GATT characteristics.
+ */
+void dataWrittenCallback(const GattCharacteristicWriteCBParams *params)
+{
+    // Ensure that initialization is finished and the host has written to the TX characteristic.
+    if ((m_uart_service_ptr != NULL) && (params->charHandle == m_uart_service_ptr->getTXCharacteristicHandle())) {
+        uint8_t  buf[MAX_REPLY_LEN];
+        uint32_t len = 0;
+
+        if (1 == params->len) {
+            switch (params->data[0]) {
+            case '0':
+                m_cmd_led = 0;
+                len = snprintf((char*) buf, MAX_REPLY_LEN, "OK");
+                break;
+            case '1':
+                m_cmd_led = 1;
+                len = snprintf((char*) buf, MAX_REPLY_LEN, "OK");
+                break;
+            case 'a':
+                len = snprintf((char*) buf, MAX_REPLY_LEN, "%d", m_analog_in_value);
+                break;
+            default:
+                len = snprintf((char*) buf, MAX_REPLY_LEN, "ERROR: Unknown char");
+                break;
+            }
+        }
+        else
+        {
+            len = snprintf((char*) buf, MAX_REPLY_LEN, "ERROR: Invalid len");
+        }
+
+        m_ble.updateCharacteristicValue(m_uart_service_ptr->getRXCharacteristicHandle(), buf, len);
+
+        DEBUG("%d bytes received from host\n\r", params->len);
+    }
+}
+
+
+/**
+ * This callback is used whenever a write to a GATT characteristic causes data to be sent to the host.
+ */
+void dataSentCallback(unsigned count)
+{
+    // NOTE: The count always seems to be 1 regardless of data.
+    DEBUG("%d bytes sent to host\n\r", count);
+}
+
+
+/**
+ * This callback is scheduled to be called periodically via a low-priority interrupt.
+ */
+void periodicCallback(void)
+{
+    m_analog_in_value = m_analog_in.read_u16();
+}
+
+
+void error(ble_error_t err, uint32_t line)
+{
+    m_error_led = 1;
+    DEBUG("Error %d on line number %d\n\r", err, line);
+}
+
+
+int main(void)
+{
+    ble_error_t err;
+    Ticker      ticker;
+
+    m_serial_port.baud(UART_BAUD_RATE);
+
+    DEBUG("Initialising\n\r");
+
+    m_cmd_led      = 0;
+    m_error_led    = 0;
+    m_analog_in_value    = 0;
+
+    ticker.attach(periodicCallback, SENSOR_READ_INTERVAL_S);
+
+    m_ble.init();
+    m_ble.onDisconnection(disconnectionCallback);
+    m_ble.onDataWritten(dataWrittenCallback);
+    m_ble.onDataSent(dataSentCallback);
+
+    // Set the TX power in dBm units.
+    // Possible values (in decreasing order): 4, 0, -4, -8, -12, -16, -20.
+    err = m_ble.setTxPower(4);
+    if (BLE_ERROR_NONE != err) {
+        error(err, __LINE__);
+    }
+
+    // Setup advertising (GAP stuff).
+    err = m_ble.setDeviceName(DEVICE_NAME);
+    if (BLE_ERROR_NONE != err) {
+        error(err, __LINE__);
+    }
+
+    err = m_ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED);
+    if (BLE_ERROR_NONE != err) {
+        error(err, __LINE__);
+    }
+
+    m_ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
+
+    err = m_ble.accumulateAdvertisingPayload(GapAdvertisingData::SHORTENED_LOCAL_NAME,
+                                                (const uint8_t *)SHORT_NAME,
+                                                (sizeof(SHORT_NAME) - 1));
+    if (BLE_ERROR_NONE != err) {
+        error(err, __LINE__);
+    }
+
+    err = m_ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_128BIT_SERVICE_IDS,
+                                                (const uint8_t *)UARTServiceUUID_reversed,
+                                                sizeof(UARTServiceUUID_reversed));
+    if (BLE_ERROR_NONE != err) {
+        error(err, __LINE__);
+    }
+
+    m_ble.setAdvertisingInterval(Gap::MSEC_TO_ADVERTISEMENT_DURATION_UNITS(ADV_INTERVAL_MS));
+    m_ble.startAdvertising();
+
+    // Create a UARTService object (GATT stuff).
+    UARTService uartService(m_ble);
+    m_uart_service_ptr = &uartService;
+
+    while (true) {
+        m_ble.waitForEvent();
+    }
+}