This is an mbed side application meant to demonstrate how to create a custom GATT service/characteristic with Evothings.

Dependencies:   BLE_API mbed nRF51822

Intro

This code is meant to be run on an mbed enabled BLE board and paired with the mbed-evothings-customGATT smartphone application.

Details

This code is a demonstration of how to create a custom service (UUID=0xA0000) with two characteristics, a read only characteristic (UUID=0xA001) and a write characteristic (UUID=0xA002). What is written to the write characteristic will be copied across to the read characteristic and broadcast out. If a single byte is written it will be used to toggle the on board LED, if more than 1 byte is written the data will be written out to the terminal. The default max size is 10bytes.

Viewing Data

You can use either the LightBlue app on iOS or the nRF Master Control Panel application on Android to view the advertising data. Alternatively you can use a custom Evothings App to view the data.

Evothings?

Evothings is a rapid prototyping environment that uses cordova to enable you to rapidly develop smartphone applications in Javascript. Please download the Evothings workbench to your computer and the Evothings client to your smartphone. Then grab the code from the github page, drag and drop the index.htm file into Evothings workbench and run it on the Evothings client.

Reference

Committer:
mbedAustin
Date:
Tue Mar 10 15:11:10 2015 +0000
Revision:
10:6acaa9f0ef85
Parent:
9:b33f42191584
Child:
11:b59226338001
Finished for Alpha Release

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedAustin 0:cd5b6733aeb1 1 #include "mbed.h"
mbedAustin 0:cd5b6733aeb1 2 #include "BLEDevice.h"
mbedAustin 1:94152e7d8b5c 3 #include "CustomService.h"
mbedAustin 1:94152e7d8b5c 4
mbedAustin 1:94152e7d8b5c 5 BLEDevice ble;
mbedAustin 1:94152e7d8b5c 6 DigitalOut led(LED1);
mbedAustin 9:b33f42191584 7 uint16_t customServiceUUID = 0xA000;
mbedAustin 9:b33f42191584 8 uint16_t reachCharUUID = 0xA001;
mbedAustin 9:b33f42191584 9 uint16_t writeCharUUID = 0xA002;
mbedAustin 1:94152e7d8b5c 10
mbedAustin 7:f6814152873c 11 const static char DEVICE_NAME[] = "ChangeMe!!"; // change this
mbedAustin 8:60ede963dfe2 12 static const uint16_t uuid16_list[] = {0xFFFF}; //Custom UUID, FFFF is reserved for development
mbedAustin 1:94152e7d8b5c 13
mbedAustin 10:6acaa9f0ef85 14 // Set Up custom Characteristics
mbedAustin 9:b33f42191584 15 static uint8_t readValue[10] = {0};
mbedAustin 9:b33f42191584 16 GattCharacteristic readChar(reachCharUUID, readValue, sizeof(readValue), sizeof(readValue),
mbedAustin 8:60ede963dfe2 17 GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
mbedAustin 2:e84c13abc479 18
mbedAustin 9:b33f42191584 19 static uint8_t writeValue[10] = {0};
mbedAustin 9:b33f42191584 20 GattCharacteristic writeChar(writeCharUUID, writeValue, sizeof(writeValue), sizeof(writeValue),
mbedAustin 8:60ede963dfe2 21 GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
mbedAustin 2:e84c13abc479 22
mbedAustin 2:e84c13abc479 23 // Set up custom service
mbedAustin 8:60ede963dfe2 24 GattCharacteristic *characteristics[] = {&readChar, &writeChar};
mbedAustin 9:b33f42191584 25 GattService customService(customServiceUUID, characteristics, sizeof(characteristics) / sizeof(GattCharacteristic *));
mbedAustin 2:e84c13abc479 26
mbedAustin 2:e84c13abc479 27
mbedAustin 8:60ede963dfe2 28 /*
mbedAustin 8:60ede963dfe2 29 * Restart advertising when phone app disconnects
mbedAustin 8:60ede963dfe2 30 */
mbedAustin 1:94152e7d8b5c 31 void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
mbedAustin 1:94152e7d8b5c 32 {
mbedAustin 8:60ede963dfe2 33 ble.startAdvertising();
mbedAustin 1:94152e7d8b5c 34 }
mbedAustin 0:cd5b6733aeb1 35
mbedAustin 8:60ede963dfe2 36 /*
mbedAustin 8:60ede963dfe2 37 * handle writes to writeCharacteristic
mbedAustin 8:60ede963dfe2 38 */
mbedAustin 4:7ef90665b399 39 void writeCharCallback(const GattCharacteristicWriteCBParams *params)
mbedAustin 3:0fb60f81f693 40 {
mbedAustin 8:60ede963dfe2 41 // check to see what characteristic was written, by handle
mbedAustin 8:60ede963dfe2 42 if(params->charHandle == writeChar.getValueHandle()) {
mbedAustin 8:60ede963dfe2 43 // toggle LED if only 1 byte is written
mbedAustin 8:60ede963dfe2 44 if(params->len == 1) {
mbedAustin 8:60ede963dfe2 45 led = params->data[0];
mbedAustin 8:60ede963dfe2 46 }
mbedAustin 8:60ede963dfe2 47 // print the data if more than 1 byte is written
mbedAustin 8:60ede963dfe2 48 else {
mbedAustin 10:6acaa9f0ef85 49 printf("0x");
mbedAustin 8:60ede963dfe2 50 for(int x=0; x < params->len; x++) {
mbedAustin 8:60ede963dfe2 51 printf("%x",params->data[x]);
mbedAustin 8:60ede963dfe2 52 }
mbedAustin 8:60ede963dfe2 53 printf("\n\r"); // print newline
mbedAustin 8:60ede963dfe2 54 }
mbedAustin 8:60ede963dfe2 55 // update the readChar with the value of writeChar
mbedAustin 8:60ede963dfe2 56 ble.updateCharacteristicValue(readChar.getValueHandle(),params->data,params->len);
mbedAustin 8:60ede963dfe2 57 }
mbedAustin 3:0fb60f81f693 58 }
mbedAustin 0:cd5b6733aeb1 59
mbedAustin 8:60ede963dfe2 60 /*
mbedAustin 8:60ede963dfe2 61 * main loop
mbedAustin 8:60ede963dfe2 62 */
mbedAustin 0:cd5b6733aeb1 63 int
mbedAustin 0:cd5b6733aeb1 64 main(void)
mbedAustin 0:cd5b6733aeb1 65 {
mbedAustin 8:60ede963dfe2 66 /* initialize stuff */
mbedAustin 8:60ede963dfe2 67 printf("\n\r********* Starting Main Loop *********\n\r");
mbedAustin 2:e84c13abc479 68 ble.init();
mbedAustin 2:e84c13abc479 69 ble.onDisconnection(disconnectionCallback);
mbedAustin 10:6acaa9f0ef85 70 ble.onDataWritten(writeCharCallback);
mbedAustin 2:e84c13abc479 71
mbedAustin 2:e84c13abc479 72 /* setup advertising */
mbedAustin 7:f6814152873c 73 ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE); // BLE only, no classic BT
mbedAustin 7:f6814152873c 74 ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED); // advertising type
mbedAustin 7:f6814152873c 75 ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME)); // add name
mbedAustin 7:f6814152873c 76 ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list)); // UUID's broadcast in advertising packet
mbedAustin 2:e84c13abc479 77 ble.setAdvertisingInterval(160); /* 100ms; in multiples of 0.625ms. */
mbedAustin 2:e84c13abc479 78
mbedAustin 8:60ede963dfe2 79 // add our custom service
mbedAustin 2:e84c13abc479 80 ble.addService(customService); // Add our custom service to device
mbedAustin 2:e84c13abc479 81
mbedAustin 7:f6814152873c 82 ble.startAdvertising(); // start advertising
mbedAustin 9:b33f42191584 83
mbedAustin 9:b33f42191584 84 // infinite loop waiting for BLE interrupt events
mbedAustin 2:e84c13abc479 85 while (true) {
mbedAustin 2:e84c13abc479 86 ble.waitForEvent(); //Save power
mbedAustin 2:e84c13abc479 87 }
mbedAustin 8:60ede963dfe2 88 }