A library for easier setup and prototyping of IoT devices (pucks), by collecting everything that is common for all pucks in one place.

Dependencies:   BLE_API nRF51822

Dependents:   ir-puck display-puck ir-puck2 BLE_ScoringDevice ... more

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Introduction

Raspberry Pi took the maker community by storm when it launched in 2012. With its internet access it allowed small projects to be internet-of-things enabled. We have created a platform to take this one step further.

Our platform, called the Puck platform, is an internet of things platform for mbed. mbed makes it easy to program embedded hardware for people new to embedded systems. Our platform is built upon the first mbed chip with Bluetooth, the nRF51822 created by Nordic Semiconductor. We hope to create a community around these BLE devices where people contribute to the project, and share their designs with each other. Everything is open-source, of course, with lots of supporting materials.

We make it easy to rapidly prototype and develop Bluetooth LE enabled devices - get up and running in under 10 lines of code.

Tutorials and in-depth documentation is available at the project's GitHub page

Pucks

We've developed a handful of awesome examples to demonstrate the platform. These examples are named 'Pucks'. By talking to the internet through your smartphone, the barrier to creating your own Internet of Things device is lower than ever.

Puck.h

Committer:
cristea
Date:
2014-07-24
Revision:
7:c07c01c2a741
Parent:
6:211ffef3b88e
Child:
8:49ffd38fb401
Child:
9:ba0527c6b6d0

File content as of revision 7:c07c01c2a741:

#ifndef __PUCK_HPP__
#define __PUCK_HPP__
 
#include "BLEDevice.h"
#include <vector>
#include "Log.h"

 enum PuckState {
    CONNECTING,
    CONNECTED,
    ADVERTISING,
    DISCONNECTED
};

const UUID stringToUUID(const char* str);

typedef void (*CharacteristicWriteCallback)(uint8_t* value);
 
 typedef struct {
     const UUID* uuid;
     std::vector<CharacteristicWriteCallback>* callbacks;
} CharacteristicWriteCallbacks;
  
 
class Puck {
    private:
        Puck() {}
        Puck(const Puck&);
        Puck& operator=(const Puck&);
        
        BLEDevice ble;        
        uint8_t beaconPayload[25];
        PuckState state;
        std::vector<GattService*> services;
        std::vector<GattCharacteristic*> characteristics;
        std::vector<CharacteristicWriteCallbacks*> writeCallbacks;
        std::vector<CharacteristicWriteCallback> pendingCallbackStack;
        std::vector<uint8_t*> pendingCallbackParameterStack;
        
        GattCharacteristic **previousCharacteristics;
        
    public:
        static Puck &getPuck();
        
        BLEDevice &getBle() { return ble; }
        PuckState getState() { return state; }
        void setState(PuckState state);        
        void init(uint16_t minor);
        void startAdvertising();
        void stopAdvertising();
        bool drive();
        void onDataWritten(uint16_t handle);
        void addCharacteristic(const UUID serviceUuid, const UUID characteristicUuid, int bytes, int properties = 0xA);
        void onCharacteristicWrite(const UUID uuid, CharacteristicWriteCallback callback);
        uint8_t* getCharacteristicValue(const UUID uuid);
};

Puck &Puck::getPuck() {
    static Puck _puckSingletonInstance;
    return _puckSingletonInstance;
}


void onDisconnection(void) {
    LOG_INFO("Disconnected.\n");
    Puck::getPuck().setState(DISCONNECTED);
}

void onConnection(void) {
    LOG_INFO("Connected.\n");
    Puck::getPuck().setState(CONNECTED);
}

void onDataWrittenCallback(uint16_t handle) {
    Puck::getPuck().onDataWritten(handle);
}

bool isEqualUUID(const UUID* uuidA, const UUID uuidB) {
    const uint8_t* uuidABase = uuidA->getBaseUUID();
    const uint8_t* uuidBBase = uuidB.getBaseUUID();
    if(uuidA->getShortUUID() != uuidB.getShortUUID()) {
        return false;
    }
    for(int i = 0; i < 16; i++) {
        if(uuidABase[i] != uuidBBase[i]) {
            return false;
        }
    }
    return true;
}

const UUID stringToUUID(const char* str) {
    uint8_t array[16];
    for(int i = 0; i < 16; i++) {
        array[i] = str[i];    
    }
    return UUID(array);
}

void Puck::setState(PuckState state) {
    LOG_DEBUG("Changed state to %i\n", state);
    this->state = state;    
}

void Puck::init(uint16_t minor) {
        /*
     * The Beacon payload (encapsulated within the MSD advertising data structure)
     * has the following composition:
     * 128-Bit UUID = E2 0A 39 F4 73 F5 4B C4 A1 2F 17 D1 AD 07 A9 61
     * Major/Minor  = 1337 / XXXX
     * Tx Power     = C8
     */
    uint8_t beaconPayloadTemplate[] = {
        0x00, 0x00, // Company identifier code (0x004C == Apple)
        0x02,       // ID
        0x15,       // length of the remaining payload
        0xE2, 0x0A, 0x39, 0xF4, 0x73, 0xF5, 0x4B, 0xC4, // UUID
        0xA1, 0x2F, 0x17, 0xD1, 0xAD, 0x07, 0xA9, 0x61,
        0x13, 0x37, // the major value to differenciate a location (Our app requires 1337 as major number)
        0x00, 0x00, // the minor value to differenciate a location (Change this to differentiate location pucks)
        0xC8        // 2's complement of the Tx power (-56dB)
    };
    beaconPayloadTemplate[22] = minor >> 8;
    beaconPayloadTemplate[23] = minor & 255;
    
    for (int i=0; i < 25; i++) {
        beaconPayload[i] = beaconPayloadTemplate[i];
    }
    
    ble.init();
    LOG_VERBOSE("Inited BLEDevice.\n");
    setState(DISCONNECTED);

    ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED);
    LOG_VERBOSE("Accumulate advertising payload: BREDR_NOT_SUPPORTED.\n");
    
    ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, beaconPayload, sizeof(beaconPayload));
    LOG_VERBOSE("Accumulate advertising payload: beacon data.\n");
    
    ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
    LOG_VERBOSE("Setting advertising type: ADV_CONNECTABLE_UNDIRECTED.\n");
    
    int hundredMillisecondsInAdvertisingIntervalFormat = 160;
    ble.setAdvertisingInterval(hundredMillisecondsInAdvertisingIntervalFormat); 
    LOG_VERBOSE("Set advertising interval: 160 (100 ms).\n");
    
    ble.onDisconnection(onDisconnection);
    ble.onConnection(onConnection);
    ble.onDataWritten(onDataWrittenCallback);
    
    for(int i = 0; i < services.size(); i++) {
        ble.addService(*services[i]);
        LOG_VERBOSE("Added service %x to BLEDevice\n", services[i]);
    }
    
    LOG_INFO("Inited puck as 0x%X.\n", minor);
}

void Puck::startAdvertising() {
    ble.startAdvertising();
    LOG_INFO("Starting to advertise.\n");
    setState(ADVERTISING);
}

void Puck::stopAdvertising() {
    if(state == ADVERTISING) {
        ble.stopAdvertising();
        LOG_INFO("Stopped advertising.\n");
        setState(DISCONNECTED);
    } else {
        LOG_WARN("Tried to stop advertising, but advertising is already stopped!\n");    
    }
}


void Puck::addCharacteristic(const UUID serviceUuid, const UUID characteristicUuid, int bytes, int properties) {
    MBED_ASSERT(bytes <= 20);
    
    uint16_t size = sizeof(uint8_t) * bytes;
    uint8_t* value = (uint8_t*) malloc(size);
    GattCharacteristic* characteristic = new GattCharacteristic(characteristicUuid, value, size, size, properties);
    characteristics.push_back(characteristic);
    GattService* service = NULL;
    int removeIndex = -1;
    for(int i = 0; i < services.size(); i++) {
        if(isEqualUUID(&services[i]->getUUID(), serviceUuid)) {
            service = services[i];
            removeIndex = i;
            break;
        }
    }
    GattCharacteristic** characteristics = NULL;
    int characteristicsLength = 0;
    if(service != NULL) {
        characteristicsLength = service->getCharacteristicCount() + 1;
        characteristics = (GattCharacteristic**) malloc(sizeof(GattCharacteristic*) * characteristicsLength);
        for(int i = 0; i < characteristicsLength; i++) {
            characteristics[i] = service->getCharacteristic(i);    
        }
        services.erase(services.begin() + removeIndex);
        delete service;
        free(previousCharacteristics);
    } else {
        characteristicsLength = 1;
        characteristics = (GattCharacteristic**) malloc(sizeof(GattCharacteristic*) * characteristicsLength);
    }
    characteristics[characteristicsLength - 1] = characteristic;
    previousCharacteristics = characteristics;
    service = new GattService(serviceUuid, characteristics, characteristicsLength);
    services.push_back(service);
}

bool Puck::drive() {
    ble.waitForEvent();
    if(state == DISCONNECTED) {
        startAdvertising();    
    }
    while(pendingCallbackStack.size() > 0) {
        LOG_VERBOSE("PendingCallbackStack size: %i\n", pendingCallbackStack.size());
        pendingCallbackStack.back()(pendingCallbackParameterStack.back());
        pendingCallbackStack.pop_back();
        pendingCallbackParameterStack.pop_back();
        LOG_VERBOSE("Callback fired\n");
    }
    return true;
}


void Puck::onCharacteristicWrite(const UUID uuid, CharacteristicWriteCallback callback) {
    CharacteristicWriteCallbacks* cb = NULL;
    for(int i = 0; i< writeCallbacks.size(); i++) {
        if(isEqualUUID(writeCallbacks[i]->uuid, uuid)) {
            cb = writeCallbacks[i];    
            break;
        }
    }
    if(cb == NULL) {
        cb = (CharacteristicWriteCallbacks*) malloc(sizeof(CharacteristicWriteCallbacks));
        cb->uuid = &uuid;
        cb->callbacks = new std::vector<CharacteristicWriteCallback>();
        writeCallbacks.push_back(cb);
    }
    cb->callbacks->push_back(callback);
    LOG_VERBOSE("Bound characteristic write callback (uuid: %x, callback: %x)\n", uuid, callback);
}


uint8_t* Puck::getCharacteristicValue(const UUID uuid) {
    LOG_VERBOSE("Reading characteristic value for UUID %x\n", uuid);
    for(int i = 0; i < characteristics.size(); i++) {
        GattCharacteristic* characteristic = characteristics[i];
        if(isEqualUUID(&characteristic->getUUID(), uuid)) {
            return characteristic->getValuePtr();
        }
    }
    LOG_WARN("Tried to read an unknown characteristic!");
    return NULL;
}


void Puck::onDataWritten(uint16_t handle) {
    for (int i = 0; i < characteristics.size(); i++) {
        GattCharacteristic* characteristic = characteristics[i];
        if (characteristic->getHandle() == handle) {
            uint16_t maxLength = characteristic->getMaxLength();
            ble.readCharacteristicValue(handle, characteristic->getValuePtr(), &maxLength);
            for(int j = 0; j < writeCallbacks.size(); j++) {    
                CharacteristicWriteCallbacks* characteristicWriteCallbacks = writeCallbacks[j];
                if(isEqualUUID(characteristicWriteCallbacks->uuid, characteristic->getUUID())) {
                    for(int k = 0; k < characteristicWriteCallbacks->callbacks->size(); k++) {
                        pendingCallbackStack.push_back(characteristicWriteCallbacks->callbacks->at(k));
                        pendingCallbackParameterStack.push_back(characteristic->getValuePtr());
                    }
                }
                return;
            }
        }
    }
}



 #endif // __PUCK_HPP__