Fork of
nRF5-DK-HeartRateDemo
by 
Bill Siever
Diff: source/main.cpp
- Revision:
- 3:f593ad98fe21
- Parent:
- 2:b850666f3c8f
- Child:
- 4:6b6018da25f6
--- a/source/main.cpp Fri Nov 11 19:25:56 2016 +0000
+++ b/source/main.cpp Fri Nov 11 20:33:07 2016 +0000
@@ -3,10 +3,10 @@
#include "ble/BLE.h"
#include "ble/Gap.h"
-// Uses the provided Service Classes:
-// (Local copies with comments are used rather than "ble/services/NAME" versions
-#include "DeviceInformationService.h"
-#include "HeartRateService.h"
+// See the official heart rate service definitions: https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.heart_rate_measurement.xml
+// This version shows a working heart rate service created with a "C style" (non object-oriented) approach.
+// It uses 8-bit heart rate values and includes "energy expended" values.
+
// If debug is "true", include code to print debugging messages to the "console"
#define DEBUG 1
@@ -19,27 +19,48 @@
/***********************************************************************
I. Global Variables:
This section declares "global variable" (variables that are used
- in multiple functions in this file)
+ in multiple functions in this file and need to exist the entire time
+ code is running (i.e., the concept of global is about both their scope
+ and their lifetime)
************************************************************************/
+// A. UUIDs for the service and its characteristics (they won't change, so declared const)
+const UUID HRMS_SERV(0x180D);
+const UUID HRMS_HRM_CHAR(0x2A37);
+const UUID HRMS_BODYSENSELOC_CHAR(0x2A38);
+const UUID HRMS_CONTROLPOINT_CHAR(0x2A39);
+
+// B. Create variables for any actual data
+uint8_t hrmHeartRateData[4] = {0x08,0,0,0}; // 1st byte: flags, 2nd byte heart date, 3-4th bytes: energy expended
+ // Flags 0x8 indicates energy expended is included and heart rate is an 8-bit value.
+uint8_t hrmBodySensorLocation = 0; // 0 is code for "Other". See https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.body_sensor_location.xml
+uint8_t hrmControlPoint = 0;
+
-// A. A way to keep track of the heart rate service object
-// Declare a pointer to a heart rate service object. (This variable isn't
-// an actual object. It's used like Java Reference Variables --- it can refer
-// to a heart rate service object, but doesn't until it is initialized)
-// Pointers are used because the heart rate service constructor requires a BLE
-// object in its constructors, which isn't available when the program first starts
-// The Object won't exist until created with "new" (
- HeartRateService *pHrs;
+// C. Create "pointers" (references) to the characteristics
+// (The actual objects are constructed at run-time)
+GattCharacteristic hrmRateChar(HRMS_HRM_CHAR, // UUID to use
+ hrmHeartRateData, // Pointer to data to use (arrays ARE pointers)
+ 4, // Number of bytes (current data)
+ 4, // Number of bytes (max)
+ GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY); // Permissions
-// B. A way to create new "events"
+// The versions below use templated classes (a congenience for a few "common" characteristic permissions)
+ReadOnlyGattCharacteristic<uint8_t> hrmLocationChar(HRMS_BODYSENSELOC_CHAR, // UUID to use
+ &hrmBodySensorLocation); // Data to use
+
+WriteOnlyGattCharacteristic<uint8_t> hrmControlPointChar(HRMS_CONTROLPOINT_CHAR, // UUID
+ &hrmControlPoint); // Data to use
+
+
+
+
+// D. A way to create new "events"
/* Total size of space for eventQueue = event count * event size */
EventQueue eventQueue( 16 * 32);
-// C. Setup the interrupt pins for any buttons
+// D. Setup the interrupt pins for any buttons
InterruptIn buttons[4] = { InterruptIn(P0_13), InterruptIn(P0_14), InterruptIn(P0_15), InterruptIn(P0_16) };
-// D. Variable to contain the heart rate value
-uint8_t heartRate = 0;
/***********************************************************************
@@ -57,6 +78,40 @@
}
+
+void onDataWritten(const GattWriteCallbackParams *params) {
+ LOG_PRINTF(__func__); // Print the function's name
+ // See: https://developer.mbed.org/teams/Bluetooth-Low-Energy/code/BLE_API/docs/65474dc93927/GattCallbackParamTypes_8h_source.html for structure
+ // A write of 1 to the "control point" should reset the energy expended
+ if (params->handle == hrmControlPointChar.getValueAttribute().getHandle()) {
+ LOG_PRINTF("Writing to HRM Control Point");
+ if(params->len == 1 && params->data[0]==1) {
+ LOG_PRINTF("Clearing HRM Control Point");
+ // If it has the correct length and data, reset
+ hrmHeartRateData[2] = 0;
+ hrmHeartRateData[3] = 0;
+ // Get the BLE object
+ BLE& ble = BLE::Instance();
+ ble.gattServer().write(hrmRateChar.getValueHandle(), hrmHeartRateData, 4);
+ }
+ }
+}
+
+void createHeartRateService() {
+ LOG_PRINTF(__func__); // Print the function's name
+
+ // Use the default BLE object:
+ BLE &ble = BLE::Instance();
+
+ GattCharacteristic *charTable[] = {&hrmRateChar, &hrmLocationChar, &hrmControlPointChar};
+ GattService hrmService(HRMS_SERV, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
+
+ ble.addService(hrmService);
+ // Add an call back when data is written.
+ ble.onDataWritten(onDataWritten);
+}
+
+
// B. Callback for things to do when the BLE object is ready
void bleInitComplete(BLE::InitializationCompleteCallbackContext *params) {
LOG_PRINTF(__func__); // Print the function's name
@@ -64,19 +119,13 @@
// Get the BLE object
BLE& ble = BLE::Instance();
- // Create the HeartRateService Object with initial value of 0 and "OTHER" location
- // (The object's constructor automatically adds the service)
- pHrs = new HeartRateService(ble, heartRate, HeartRateService::LOCATION_OTHER);
-
- // Add in a Device Information Service object too.
- // Argument order: "Manufacturer", "Model No", "Serial No", "Hardware Rev", "Firmware Rev", "Software Rev"
- new DeviceInformationService(ble, "Acme", "1A", "123", "v1.1", "r2a", "r3");
+ // Create the HeartRateService
+ createHeartRateService();
// Setup the "onDisconnection()" callback
// Connection info is handeled by GAP (Generic ACCESS Protocol), hence the ble.gap() part
ble.gap().onDisconnection(bleDisconnectionCallback);
-
// Setup advertising: Build the "payload"
// Add in the mode (discoverable / low energy only)
ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
@@ -102,6 +151,10 @@
void buttonsPress() {
LOG_PRINTF(__func__); // Print the function's name
+
+ // Get access to the BLE object
+ BLE &ble = BLE::Instance();
+
// Display the buttons that are pressed
// Do NOT use printf() in callbacks. Put all printing on tasks handled by the event queue.
@@ -111,13 +164,28 @@
LOG_PRINTF("\t%d down\r\n",i+1);
}
if(buttons[0].read()==0) {
- heartRate++;
- pHrs->updateHeartRate(heartRate);
+ // Increase the heart rate and update
+ hrmHeartRateData[1]++;
+ ble.gattServer().write(hrmRateChar.getValueHandle(), hrmHeartRateData, 4);
} else
if(buttons[1].read()==0) {
- heartRate--;
- pHrs->updateHeartRate(heartRate);
+ hrmHeartRateData[1]--;
+ ble.gattServer().write(hrmRateChar.getValueHandle(), hrmHeartRateData, 4);
}
+ if(buttons[2].read()==0) {
+ unsigned energy = hrmHeartRateData[2] | hrmHeartRateData[3]<<8;
+ energy++;
+ hrmHeartRateData[2] = energy & 0xFF;
+ hrmHeartRateData[3] = energy >> 8;
+ ble.gattServer().write(hrmRateChar.getValueHandle(), hrmHeartRateData, 4);
+ }
+ if(buttons[3].read()==0) {
+ unsigned energy = hrmHeartRateData[2] | hrmHeartRateData[3]<<8;
+ energy--;
+ hrmHeartRateData[2] = energy & 0xFF;
+ hrmHeartRateData[3] = energy >> 8;
+ ble.gattServer().write(hrmRateChar.getValueHandle(), hrmHeartRateData, 4);
+ }
}
// C. Callback to respond to BLE events. This will add a function call to the