mbed-os-examples » Code » mbed-os-example-ble-GAPButton

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

This application shows how to use GAP to transmit a simple value to disconnected peer listening for advertisement every time that a value is updated. The canonical source for this example lives at: https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_GAPButton

Button count over GAP

This application shows how to use GAP to transmit a simple value to disconnected peer listening for advertisement every time that a value is updated:

The value is a count of how many times a button on the device was pressed (the code actually monitors the button's releases, not press downs).

We transmit the value in the SERVICE_DATA field of the advertising payload.

Running the application

Requirements

The sample application can be seen on any BLE scanner on a smartphone. If you don't have a scanner on your phone, please install :

- 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.

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

Find your device; it should be named `GAPButton`; and look at the advertisement broadcasted by your device (there is no need to connect to your device).

figure 2 Scan results using nRF Master Control Panel 4.0.5.

The Service Data field of the advertisement packet broadcasted by your device reflects the button press count. The starting value is 0.

figure 3 Initial state of the button using nRF Master Control Panel 4.0.5.

Press the button on the device.

figure 3 State after 1 button press using nRF Master Control Panel 4.0.5.

The Service Data field value of the advertisement packet should change every time you press the button.

figure 3 State after 6 button press using nRF Master Control Panel 4.0.5.

Note

Since broadcasting is not reliable and your phone may scan intermittently, it is possible that your phone will miss button updates.

source/main.cpp@47:70f571463f31, 2017-11-01 (annotated)

Committer:: mbed_official
Date:: Wed Nov 01 15:30:48 2017 +0000
Revision:: 47:70f571463f31
Parent:: 30:217bfc94a9b7
Child:: 78:3f848aa75a8a

Merge pull request #112 from marcbonnici/master



Add MAC address printouts to examples

.

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

Who changed what in which revision?

User	Revision	Line number	New contents of line
mbed_official	3:f0ed4199b362	1	/* mbed Microcontroller Library
mbed_official	3:f0ed4199b362	2	* Copyright (c) 2006-2013 ARM Limited
mbed_official	3:f0ed4199b362	3	*
mbed_official	3:f0ed4199b362	4	* Licensed under the Apache License, Version 2.0 (the "License");
mbed_official	3:f0ed4199b362	5	* you may not use this file except in compliance with the License.
mbed_official	3:f0ed4199b362	6	* You may obtain a copy of the License at
mbed_official	3:f0ed4199b362	7	*
mbed_official	3:f0ed4199b362	8	* http://www.apache.org/licenses/LICENSE-2.0
mbed_official	3:f0ed4199b362	9	*
mbed_official	3:f0ed4199b362	10	* Unless required by applicable law or agreed to in writing, software
mbed_official	3:f0ed4199b362	11	* distributed under the License is distributed on an "AS IS" BASIS,
mbed_official	3:f0ed4199b362	12	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official	3:f0ed4199b362	13	* See the License for the specific language governing permissions and
mbed_official	3:f0ed4199b362	14	* limitations under the License.
mbed_official	3:f0ed4199b362	15	*/
mbed_official	3:f0ed4199b362	16
mbed_official	14:332bb3fa072b	17	#include <events/mbed_events.h>
mbed_official	3:f0ed4199b362	18	#include <mbed.h>
mbed_official	3:f0ed4199b362	19	#include "ble/BLE.h"
mbed_official	3:f0ed4199b362	20
mbed_official	3:f0ed4199b362	21	DigitalOut led1(LED1, 1);
mbed_official	6:bfe23efb0d97	22	InterruptIn button(BLE_BUTTON_PIN_NAME);
mbed_official	3:f0ed4199b362	23	uint8_t cnt;
mbed_official	3:f0ed4199b362	24
mbed_official	3:f0ed4199b362	25	// Change your device name below
mbed_official	3:f0ed4199b362	26	const char DEVICE_NAME[] = "GAPButton";
mbed_official	3:f0ed4199b362	27
mbed_official	3:f0ed4199b362	28	/* We can arbiturarily choose the GAPButton service UUID to be 0xAA00
mbed_official	3:f0ed4199b362	29	* as long as it does not overlap with the UUIDs defined here:
mbed_official	3:f0ed4199b362	30	* https://developer.bluetooth.org/gatt/services/Pages/ServicesHome.aspx */
mbed_official	3:f0ed4199b362	31	#define GAPButtonUUID 0xAA00
mbed_official	3:f0ed4199b362	32	const uint16_t uuid16_list[] = {GAPButtonUUID};
mbed_official	3:f0ed4199b362	33
mbed_official	30:217bfc94a9b7	34	static EventQueue eventQueue(/* event count / 16 EVENTS_EVENT_SIZE);
mbed_official	3:f0ed4199b362	35
mbed_official	3:f0ed4199b362	36	void print_error(ble_error_t error, const char* msg)
mbed_official	3:f0ed4199b362	37	{
mbed_official	3:f0ed4199b362	38	printf("%s: ", msg);
mbed_official	3:f0ed4199b362	39	switch(error) {
mbed_official	3:f0ed4199b362	40	case BLE_ERROR_NONE:
mbed_official	3:f0ed4199b362	41	printf("BLE_ERROR_NONE: No error");
mbed_official	3:f0ed4199b362	42	break;
mbed_official	3:f0ed4199b362	43	case BLE_ERROR_BUFFER_OVERFLOW:
mbed_official	3:f0ed4199b362	44	printf("BLE_ERROR_BUFFER_OVERFLOW: The requested action would cause a buffer overflow and has been aborted");
mbed_official	3:f0ed4199b362	45	break;
mbed_official	3:f0ed4199b362	46	case BLE_ERROR_NOT_IMPLEMENTED:
mbed_official	3:f0ed4199b362	47	printf("BLE_ERROR_NOT_IMPLEMENTED: Requested a feature that isn't yet implement or isn't supported by the target HW");
mbed_official	3:f0ed4199b362	48	break;
mbed_official	3:f0ed4199b362	49	case BLE_ERROR_PARAM_OUT_OF_RANGE:
mbed_official	3:f0ed4199b362	50	printf("BLE_ERROR_PARAM_OUT_OF_RANGE: One of the supplied parameters is outside the valid range");
mbed_official	3:f0ed4199b362	51	break;
mbed_official	3:f0ed4199b362	52	case BLE_ERROR_INVALID_PARAM:
mbed_official	3:f0ed4199b362	53	printf("BLE_ERROR_INVALID_PARAM: One of the supplied parameters is invalid");
mbed_official	3:f0ed4199b362	54	break;
mbed_official	3:f0ed4199b362	55	case BLE_STACK_BUSY:
mbed_official	3:f0ed4199b362	56	printf("BLE_STACK_BUSY: The stack is busy");
mbed_official	3:f0ed4199b362	57	break;
mbed_official	3:f0ed4199b362	58	case BLE_ERROR_INVALID_STATE:
mbed_official	3:f0ed4199b362	59	printf("BLE_ERROR_INVALID_STATE: Invalid state");
mbed_official	3:f0ed4199b362	60	break;
mbed_official	3:f0ed4199b362	61	case BLE_ERROR_NO_MEM:
mbed_official	3:f0ed4199b362	62	printf("BLE_ERROR_NO_MEM: Out of Memory");
mbed_official	3:f0ed4199b362	63	break;
mbed_official	3:f0ed4199b362	64	case BLE_ERROR_OPERATION_NOT_PERMITTED:
mbed_official	3:f0ed4199b362	65	printf("BLE_ERROR_OPERATION_NOT_PERMITTED");
mbed_official	3:f0ed4199b362	66	break;
mbed_official	3:f0ed4199b362	67	case BLE_ERROR_INITIALIZATION_INCOMPLETE:
mbed_official	3:f0ed4199b362	68	printf("BLE_ERROR_INITIALIZATION_INCOMPLETE");
mbed_official	3:f0ed4199b362	69	break;
mbed_official	3:f0ed4199b362	70	case BLE_ERROR_ALREADY_INITIALIZED:
mbed_official	3:f0ed4199b362	71	printf("BLE_ERROR_ALREADY_INITIALIZED");
mbed_official	3:f0ed4199b362	72	break;
mbed_official	3:f0ed4199b362	73	case BLE_ERROR_UNSPECIFIED:
mbed_official	3:f0ed4199b362	74	printf("BLE_ERROR_UNSPECIFIED: Unknown error");
mbed_official	3:f0ed4199b362	75	break;
mbed_official	3:f0ed4199b362	76	case BLE_ERROR_INTERNAL_STACK_FAILURE:
mbed_official	3:f0ed4199b362	77	printf("BLE_ERROR_INTERNAL_STACK_FAILURE: internal stack faillure");
mbed_official	3:f0ed4199b362	78	break;
mbed_official	3:f0ed4199b362	79	}
mbed_official	3:f0ed4199b362	80	printf("\r\n");
mbed_official	3:f0ed4199b362	81	}
mbed_official	3:f0ed4199b362	82
mbed_official	3:f0ed4199b362	83	void updatePayload(void)
mbed_official	3:f0ed4199b362	84	{
mbed_official	3:f0ed4199b362	85	// Update the count in the SERVICE_DATA field of the advertising payload
mbed_official	3:f0ed4199b362	86	uint8_t service_data[3];
mbed_official	3:f0ed4199b362	87	service_data[0] = GAPButtonUUID & 0xff;
mbed_official	3:f0ed4199b362	88	service_data[1] = GAPButtonUUID >> 8;
mbed_official	3:f0ed4199b362	89	service_data[2] = cnt; // Put the button click count in the third byte
mbed_official	3:f0ed4199b362	90	ble_error_t err = BLE::Instance().gap().updateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, (uint8_t *)service_data, sizeof(service_data));
mbed_official	3:f0ed4199b362	91	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	92	print_error(err, "Updating payload failed");
mbed_official	3:f0ed4199b362	93	}
mbed_official	3:f0ed4199b362	94	}
mbed_official	3:f0ed4199b362	95
mbed_official	3:f0ed4199b362	96	void buttonPressedCallback(void)
mbed_official	3:f0ed4199b362	97	{
mbed_official	3:f0ed4199b362	98	++cnt;
mbed_official	3:f0ed4199b362	99
mbed_official	3:f0ed4199b362	100	// Calling BLE api in interrupt context may cause race conditions
mbed_official	3:f0ed4199b362	101	// Using mbed-events to schedule calls to BLE api for safety
mbed_official	14:332bb3fa072b	102	eventQueue.call(updatePayload);
mbed_official	3:f0ed4199b362	103	}
mbed_official	3:f0ed4199b362	104
mbed_official	3:f0ed4199b362	105	void blinkCallback(void)
mbed_official	3:f0ed4199b362	106	{
mbed_official	3:f0ed4199b362	107	led1 = !led1;
mbed_official	3:f0ed4199b362	108	}
mbed_official	3:f0ed4199b362	109
mbed_official	47:70f571463f31	110	void printMacAddress()
mbed_official	47:70f571463f31	111	{
mbed_official	47:70f571463f31	112	/* Print out device MAC address to the console*/
mbed_official	47:70f571463f31	113	Gap::AddressType_t addr_type;
mbed_official	47:70f571463f31	114	Gap::Address_t address;
mbed_official	47:70f571463f31	115	BLE::Instance().gap().getAddress(&addr_type, address);
mbed_official	47:70f571463f31	116	printf("DEVICE MAC ADDRESS: ");
mbed_official	47:70f571463f31	117	for (int i = 5; i >= 1; i--){
mbed_official	47:70f571463f31	118	printf("%02x:", address[i]);
mbed_official	47:70f571463f31	119	}
mbed_official	47:70f571463f31	120	printf("%02x\r\n", address[0]);
mbed_official	47:70f571463f31	121	}
mbed_official	47:70f571463f31	122
mbed_official	3:f0ed4199b362	123	void bleInitComplete(BLE::InitializationCompleteCallbackContext *context)
mbed_official	3:f0ed4199b362	124	{
mbed_official	3:f0ed4199b362	125	BLE& ble = context->ble;
mbed_official	3:f0ed4199b362	126	ble_error_t err = context->error;
mbed_official	3:f0ed4199b362	127
mbed_official	3:f0ed4199b362	128	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	129	print_error(err, "BLE initialisation failed");
mbed_official	3:f0ed4199b362	130	return;
mbed_official	3:f0ed4199b362	131	}
mbed_official	3:f0ed4199b362	132
mbed_official	3:f0ed4199b362	133	// Set up the advertising flags. Note: not all combination of flags are valid
mbed_official	3:f0ed4199b362	134	// BREDR_NOT_SUPPORTED: Device does not support Basic Rate or Enchanced Data Rate, It is Low Energy only.
mbed_official	3:f0ed4199b362	135	// LE_GENERAL_DISCOVERABLE: Peripheral device is discoverable at any moment
mbed_official	3:f0ed4199b362	136	err = ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED \| GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
mbed_official	3:f0ed4199b362	137	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	138	print_error(err, "Setting GAP flags failed");
mbed_official	3:f0ed4199b362	139	return;
mbed_official	3:f0ed4199b362	140	}
mbed_official	3:f0ed4199b362	141
mbed_official	3:f0ed4199b362	142	// Put the device name in the advertising payload
mbed_official	3:f0ed4199b362	143	err = ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
mbed_official	3:f0ed4199b362	144	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	145	print_error(err, "Setting device name failed");
mbed_official	3:f0ed4199b362	146	return;
mbed_official	3:f0ed4199b362	147	}
mbed_official	3:f0ed4199b362	148
mbed_official	3:f0ed4199b362	149	err = ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list));
mbed_official	3:f0ed4199b362	150	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	151	print_error(err, "Setting service UUID failed");
mbed_official	3:f0ed4199b362	152	return;
mbed_official	3:f0ed4199b362	153	}
mbed_official	3:f0ed4199b362	154
mbed_official	3:f0ed4199b362	155	// The Service Data data type consists of a service UUID with the data associated with that service.
mbed_official	3:f0ed4199b362	156	// We will encode the number of button clicks in the Service Data field
mbed_official	3:f0ed4199b362	157	// First two bytes of SERVICE_DATA field should contain the UUID of the service
mbed_official	3:f0ed4199b362	158	uint8_t service_data[3];
mbed_official	3:f0ed4199b362	159	service_data[0] = GAPButtonUUID & 0xff;
mbed_official	3:f0ed4199b362	160	service_data[1] = GAPButtonUUID >> 8;
mbed_official	3:f0ed4199b362	161	service_data[2] = cnt; // Put the button click count in the third byte
mbed_official	3:f0ed4199b362	162	err = ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, (uint8_t *)service_data, sizeof(service_data));
mbed_official	3:f0ed4199b362	163	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	164	print_error(err, "Setting service data failed");
mbed_official	3:f0ed4199b362	165	return;
mbed_official	3:f0ed4199b362	166	}
mbed_official	3:f0ed4199b362	167
mbed_official	3:f0ed4199b362	168	// It is not connectable as we are just boardcasting
mbed_official	3:f0ed4199b362	169	ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
mbed_official	3:f0ed4199b362	170
mbed_official	3:f0ed4199b362	171	// Send out the advertising payload every 1000ms
mbed_official	3:f0ed4199b362	172	ble.gap().setAdvertisingInterval(1000);
mbed_official	3:f0ed4199b362	173
mbed_official	3:f0ed4199b362	174	err = ble.gap().startAdvertising();
mbed_official	3:f0ed4199b362	175	if (err != BLE_ERROR_NONE) {
mbed_official	47:70f571463f31	176	print_error(err, "Start advertising failed");
mbed_official	3:f0ed4199b362	177	return;
mbed_official	3:f0ed4199b362	178	}
mbed_official	47:70f571463f31	179
mbed_official	47:70f571463f31	180	printMacAddress();
mbed_official	3:f0ed4199b362	181	}
mbed_official	3:f0ed4199b362	182
mbed_official	3:f0ed4199b362	183	void scheduleBleEventsProcessing(BLE::OnEventsToProcessCallbackContext* context) {
mbed_official	3:f0ed4199b362	184	BLE &ble = BLE::Instance();
mbed_official	14:332bb3fa072b	185	eventQueue.call(Callback<void()>(&ble, &BLE::processEvents));
mbed_official	3:f0ed4199b362	186	}
mbed_official	3:f0ed4199b362	187
mbed_official	3:f0ed4199b362	188	int main()
mbed_official	3:f0ed4199b362	189	{
mbed_official	3:f0ed4199b362	190	cnt = 0;
mbed_official	3:f0ed4199b362	191
mbed_official	3:f0ed4199b362	192	BLE &ble = BLE::Instance();
mbed_official	3:f0ed4199b362	193	ble.onEventsToProcess(scheduleBleEventsProcessing);
mbed_official	3:f0ed4199b362	194	ble_error_t err = ble.init(bleInitComplete);
mbed_official	3:f0ed4199b362	195	if (err != BLE_ERROR_NONE) {
mbed_official	3:f0ed4199b362	196	print_error(err, "BLE initialisation failed");
mbed_official	3:f0ed4199b362	197	return 0;
mbed_official	3:f0ed4199b362	198	}
mbed_official	3:f0ed4199b362	199
mbed_official	3:f0ed4199b362	200	// Blink LED every 500 ms to indicate system aliveness
mbed_official	14:332bb3fa072b	201	eventQueue.call_every(500, blinkCallback);
mbed_official	3:f0ed4199b362	202
mbed_official	3:f0ed4199b362	203	// Register function to be called when button is released
mbed_official	3:f0ed4199b362	204	button.rise(buttonPressedCallback);
mbed_official	3:f0ed4199b362	205
mbed_official	14:332bb3fa072b	206	eventQueue.dispatch_forever();
mbed_official	3:f0ed4199b362	207
mbed_official	3:f0ed4199b362	208	return 0;
mbed_official	3:f0ed4199b362	209	}

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Type:	Program
Mbed OS support:	Mbed OS
Created:	26 Jul 2016
Imports:	289
Forks:	0
Commits:	86
Dependents:	0
Dependencies:	0
Followers:	207