mbed-os-examples / Mbed OS mbed-os-example-ble-HeartRate

This application transmits a heart rate value using the Bluetooth SIG Heart Rate Profile. The heart rate value is provided by the application itself, not by a sensor, so that you don't have to get a sensor just to run the example. The canonical source for this example lives at https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_HeartRate

BLE Heart Rate Monitor

This application transmits a heart rate value using the Bluetooth SIG Heart Rate Profile. The heart rate value is provided by the application itself, not by a sensor, so that you don't have to get a sensor just to run the example.

Technical details are better presented in the mbed Classic equivalent of this example.

Running the application

Requirements

To see the heart rate information on your phone, download Panobike for iOS or Android.

You could also use a generic BLE scanners:

- nRF Master Control Panel for Android.

- LightBlue for iPhone.

Hardware requirements are in the main readme.

Building instructions

Building with mbed-cli

If you'd like to use mbed-cli to build this, then you should refer to the main readme. The instructions here relate to using the developer.mbed.org Online Compiler

In order to build this example in the mbed Online Compiler, first import the example using the ‘Import’ button on the right hand side.

Next, select a platform to build for. This must either be a platform that supports BLE, for example the NRF51-DK, or one of the following:

List of platforms supporting Bluetooth Low Energy

Or you must also add a piece of hardware and the supporting library that includes a Bluetooth Low Energy driver for that hardware, for example the K64F or NUCLEO_F401RE with the X-NUCLEO-IDB05A1

List of components supporting Bluetooth Low Energy.

Once you have selected your platform, compile the example and drag and drop the resulting binary onto your board.

For general instructions on using the mbed Online Compiler, please see the mbed Handbook

Checking for success

Note: Screens captures depicted below show what is expected from this example if the scanner used is nRF Master Control Panel version 4.0.5. If you encounter any difficulties consider trying another scanner or another version of nRF Master Control Panel. Alternative scanners may require reference to their manuals.

  • Build the application and install it on your board as explained in the building instructions.
  • Open the BLE scanner on your phone.
  • Start a scan.

/media/uploads/vcoubard/start_scan.png

figure 1 How to start scan using nRF Master Control Panel 4.0.5

  • Find your device; it should be named `HRM`.

/media/uploads/vcoubard/scan_result.png

figure 2 Scan results using nRF Master Control Panel 4.0.5

  • Establish a connection with your device.

/media/uploads/vcoubard/connection.png

figure 3 How to establish a connection using Master Control Panel 4.0.5

  • Discover the services and the characteristics on the device. The *Heart Rate* service has the UUID `0x180D` and includes the *Heart Rate Measurement* characteristic which has the UUID `0x2A37`.

/media/uploads/vcoubard/discovery.png

figure 4 Representation of the Heart Rate service using Master Control Panel 4.0.5

  • Register for the notifications sent by the Heart Rate Measurement characteristic.

/media/uploads/vcoubard/register_to_notifications.png

figure 5 How to register to notifications using Master Control Panel 4.0.5

  • You should see the heart rate value change every half second. It begins at 100, goes up to 175 (in steps of 1), resets to 100 and so on.

/media/uploads/vcoubard/notifications.png

figure 6 Notifications view using Master Control Panel 4.0.5

source/main.cpp@21:ec1d136a5a06, 2017-03-14 (annotated)

Committer:
mbed_official
Date:
Tue Mar 14 15:45:40 2017 +0000
Revision:
21:ec1d136a5a06
Parent:
10:ac3615194d04
Child:
26:d7dd71a8aea1
Merge pull request #68 from adbridge/master



Updating mbed-os to mbed-os-5.4.1

.

Commit copied from https://github.com/ARMmbed/mbed-os-example-ble

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 1:72c60abef7e7 1 /* mbed Microcontroller Library
mbed_official 1:72c60abef7e7 2 * Copyright (c) 2006-2015 ARM Limited
mbed_official 1:72c60abef7e7 3 *
mbed_official 1:72c60abef7e7 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 1:72c60abef7e7 5 * you may not use this file except in compliance with the License.
mbed_official 1:72c60abef7e7 6 * You may obtain a copy of the License at
mbed_official 1:72c60abef7e7 7 *
mbed_official 1:72c60abef7e7 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 1:72c60abef7e7 9 *
mbed_official 1:72c60abef7e7 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 1:72c60abef7e7 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 1:72c60abef7e7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 1:72c60abef7e7 13 * See the License for the specific language governing permissions and
mbed_official 1:72c60abef7e7 14 * limitations under the License.
mbed_official 1:72c60abef7e7 15 */
mbed_official 1:72c60abef7e7 16
mbed_official 10:ac3615194d04 17 #include <events/mbed_events.h>
mbed_official 1:72c60abef7e7 18 #include <mbed.h>
mbed_official 1:72c60abef7e7 19 #include "ble/BLE.h"
mbed_official 1:72c60abef7e7 20 #include "ble/Gap.h"
mbed_official 1:72c60abef7e7 21 #include "ble/services/HeartRateService.h"
mbed_official 1:72c60abef7e7 22
mbed_official 1:72c60abef7e7 23 DigitalOut led1(LED1, 1);
mbed_official 1:72c60abef7e7 24
mbed_official 1:72c60abef7e7 25 const static char DEVICE_NAME[] = "HRM";
mbed_official 1:72c60abef7e7 26 static const uint16_t uuid16_list[] = {GattService::UUID_HEART_RATE_SERVICE};
mbed_official 1:72c60abef7e7 27
mbed_official 1:72c60abef7e7 28 static uint8_t hrmCounter = 100; // init HRM to 100bps
mbed_official 1:72c60abef7e7 29 static HeartRateService *hrServicePtr;
mbed_official 1:72c60abef7e7 30
mbed_official 1:72c60abef7e7 31 static EventQueue eventQueue(
mbed_official 1:72c60abef7e7 32 /* event count */ 16 * /* event size */ 32
mbed_official 1:72c60abef7e7 33 );
mbed_official 1:72c60abef7e7 34
mbed_official 1:72c60abef7e7 35 void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
mbed_official 1:72c60abef7e7 36 {
mbed_official 1:72c60abef7e7 37 BLE::Instance().gap().startAdvertising(); // restart advertising
mbed_official 1:72c60abef7e7 38 }
mbed_official 1:72c60abef7e7 39
mbed_official 1:72c60abef7e7 40 void updateSensorValue() {
mbed_official 1:72c60abef7e7 41 // Do blocking calls or whatever is necessary for sensor polling.
mbed_official 1:72c60abef7e7 42 // In our case, we simply update the HRM measurement.
mbed_official 1:72c60abef7e7 43 hrmCounter++;
mbed_official 1:72c60abef7e7 44
mbed_official 1:72c60abef7e7 45 // 100 <= HRM bps <=175
mbed_official 1:72c60abef7e7 46 if (hrmCounter == 175) {
mbed_official 1:72c60abef7e7 47 hrmCounter = 100;
mbed_official 1:72c60abef7e7 48 }
mbed_official 1:72c60abef7e7 49
mbed_official 1:72c60abef7e7 50 hrServicePtr->updateHeartRate(hrmCounter);
mbed_official 1:72c60abef7e7 51 }
mbed_official 1:72c60abef7e7 52
mbed_official 1:72c60abef7e7 53 void periodicCallback(void)
mbed_official 1:72c60abef7e7 54 {
mbed_official 1:72c60abef7e7 55 led1 = !led1; /* Do blinky on LED1 while we're waiting for BLE events */
mbed_official 1:72c60abef7e7 56
mbed_official 1:72c60abef7e7 57 if (BLE::Instance().getGapState().connected) {
mbed_official 10:ac3615194d04 58 eventQueue.call(updateSensorValue);
mbed_official 1:72c60abef7e7 59 }
mbed_official 1:72c60abef7e7 60 }
mbed_official 1:72c60abef7e7 61
mbed_official 1:72c60abef7e7 62 void onBleInitError(BLE &ble, ble_error_t error)
mbed_official 1:72c60abef7e7 63 {
mbed_official 1:72c60abef7e7 64 (void)ble;
mbed_official 1:72c60abef7e7 65 (void)error;
mbed_official 1:72c60abef7e7 66 /* Initialization error handling should go here */
mbed_official 1:72c60abef7e7 67 }
mbed_official 1:72c60abef7e7 68
mbed_official 1:72c60abef7e7 69 void bleInitComplete(BLE::InitializationCompleteCallbackContext *params)
mbed_official 1:72c60abef7e7 70 {
mbed_official 1:72c60abef7e7 71 BLE& ble = params->ble;
mbed_official 1:72c60abef7e7 72 ble_error_t error = params->error;
mbed_official 1:72c60abef7e7 73
mbed_official 1:72c60abef7e7 74 if (error != BLE_ERROR_NONE) {
mbed_official 1:72c60abef7e7 75 onBleInitError(ble, error);
mbed_official 1:72c60abef7e7 76 return;
mbed_official 1:72c60abef7e7 77 }
mbed_official 1:72c60abef7e7 78
mbed_official 1:72c60abef7e7 79 if (ble.getInstanceID() != BLE::DEFAULT_INSTANCE) {
mbed_official 1:72c60abef7e7 80 return;
mbed_official 1:72c60abef7e7 81 }
mbed_official 1:72c60abef7e7 82
mbed_official 1:72c60abef7e7 83 ble.gap().onDisconnection(disconnectionCallback);
mbed_official 1:72c60abef7e7 84
mbed_official 1:72c60abef7e7 85 /* Setup primary service. */
mbed_official 1:72c60abef7e7 86 hrServicePtr = new HeartRateService(ble, hrmCounter, HeartRateService::LOCATION_FINGER);
mbed_official 1:72c60abef7e7 87
mbed_official 1:72c60abef7e7 88 /* Setup advertising. */
mbed_official 1:72c60abef7e7 89 ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
mbed_official 1:72c60abef7e7 90 ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list));
mbed_official 1:72c60abef7e7 91 ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::GENERIC_HEART_RATE_SENSOR);
mbed_official 1:72c60abef7e7 92 ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
mbed_official 1:72c60abef7e7 93 ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
mbed_official 1:72c60abef7e7 94 ble.gap().setAdvertisingInterval(1000); /* 1000ms */
mbed_official 1:72c60abef7e7 95 ble.gap().startAdvertising();
mbed_official 1:72c60abef7e7 96 }
mbed_official 1:72c60abef7e7 97
mbed_official 1:72c60abef7e7 98 void scheduleBleEventsProcessing(BLE::OnEventsToProcessCallbackContext* context) {
mbed_official 1:72c60abef7e7 99 BLE &ble = BLE::Instance();
mbed_official 10:ac3615194d04 100 eventQueue.call(Callback<void()>(&ble, &BLE::processEvents));
mbed_official 1:72c60abef7e7 101 }
mbed_official 1:72c60abef7e7 102
mbed_official 1:72c60abef7e7 103 int main()
mbed_official 1:72c60abef7e7 104 {
mbed_official 10:ac3615194d04 105 eventQueue.call_every(500, periodicCallback);
mbed_official 1:72c60abef7e7 106
mbed_official 1:72c60abef7e7 107 BLE &ble = BLE::Instance();
mbed_official 1:72c60abef7e7 108 ble.onEventsToProcess(scheduleBleEventsProcessing);
mbed_official 1:72c60abef7e7 109 ble.init(bleInitComplete);
mbed_official 1:72c60abef7e7 110
mbed_official 10:ac3615194d04 111 eventQueue.dispatch_forever();
mbed_official 1:72c60abef7e7 112
mbed_official 1:72c60abef7e7 113 return 0;
mbed_official 1:72c60abef7e7 114 }