Adding an initial implementation for Eddystone beacon service.

This commit is contained in:
Rohit Grover 2015-08-07 15:27:08 +01:00
parent 45813579a5
commit bff44f94a6

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/* mbed Microcontroller Library
* Copyright (c) 2006-2015 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SERVICES_EDDYSTONEBEACON_H_
#define SERVICES_EDDYSTONEBEACON_H_
#include "ble/BLE.h"
#include "mbed.h"
static const uint8_t BEACON_EDDYSTONE[] = {0xAA, 0xFE};
#if 0
#define INFO(MSG, ...) printf("[EddyStone: INFO]" MSG " \t[%s,%d]\r\n", ##__VA_ARGS__, __FILE__, __LINE__);
#define DBG(MSG, ...) printf("[EddyStone: DBG]" MSG " \t[%s,%d]\r\n", ##__VA_ARGS__, __FILE__, __LINE__);
#define WARN(MSG, ...) printf("[EddyStone: WARN]" MSG " \t[%s,%d]\r\n", ##__VA_ARGS__, __FILE__, __LINE__);
#define ERR(MSG, ...) printf("[EddyStone: ERR]" MSG " \t[%s,%d]\r\n", ##__VA_ARGS__, __FILE__, __LINE__);
#else
#define INFO(MSG, ...)
#define DBG(MSG, ...)
#define WARN(MSG, ...)
#define ERR(MSG, ...)
#endif // if 0
/**
* @class Eddystone
* @brief Eddystone Configuration Service. Can be used to set URL, adjust power levels, and set flags.
* See https://github.com/google/eddystone
*
*/
class EddystoneService
{
public:
static const unsigned ADVERTISING_INTERVAL_MSEC = 1000; // Advertising interval for config service.
static const size_t SERVICE_DATA_MAX = 31; // Maximum size of service data in ADV packets
static const size_t URI_DATA_MAX = 18;
typedef uint8_t UriData_t[URI_DATA_MAX];
// UID Frame Type subfields
static const size_t UID_NAMESPACEID_SIZE = 10;
static const size_t UID_INSTANCEID_SIZE = 6;
typedef uint8_t UIDNamespaceID_t[UID_NAMESPACEID_SIZE];
typedef uint8_t UIDInstanceID_t[UID_INSTANCEID_SIZE];
// Eddystone Frame Type ID
enum {
FRAME_TYPE_UID = 0x00,
FRAME_TYPE_URL = 0x10,
FRAME_TYPE_TLM = 0x20,
NUM_FRAMETYPES = 3
};
static const uint8_t FRAME_SIZE_UID = 20; // includes RFU bytes
static const uint8_t FRAME_SIZE_TLM = 14; // TLM frame is a constant 14Bytes
public:
/**
* Constructor: sets up the parameters used by the Eddystone beacon.
* This function should be used in lieu of the config service.
*
* @param bleIn
* ble object for the underlying controller.
* @oaram interval
* This is is how often broadcasts are made (in units of milliseconds).
* @param txPowerLevel
* The broadcasting power level (in dbM).
* @param UIDNamespaceID
* 10-Byte Namespace UUID.
* @param UIDInstanceID
* 6-Byte Instance UUID.
* @param url
* Shortened URL to broadcast (pass in as a string).
* @param tlmVersion
* version of telemetry data field to use (default to 0x00).
*/
EddystoneService(BLEDevice &bleIn,
uint16_t interval = 100,
uint8_t txPowerLevel = 0,
const uint8_t *UIDNamespaceID = NULL,
const uint8_t *UIDInstanceID = NULL,
const char *url = NULL,
uint8_t tlmVersion = 0) :
ble(bleIn),
uidIsSet(false),
urlIsSet(false),
frameIndex(0),
uidRFU(0),
switchFlag(true),
TlmPduCount(0),
TlmTimeSinceBoot(0)
{
// Check optional frames, set their 'isSet' flags appropriately
if ((UIDNamespaceID != NULL) & (UIDInstanceID != NULL)) {
setUIDFrameData(txPowerLevel, UIDNamespaceID, UIDInstanceID);
uidIsSet = true;
} else if (url != NULL) {
setURLFrameData(txPowerLevel, url);
urlIsSet = true;
} else {
// Default TLM frame to version 0x00, start all values at zero to be spec compliant.
setTLMFrameData(tlmVersion, 0x00, 0x00);
}
ble.gap().setTxPower(txPowerLevel);
ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
ble.gap().setAdvertisingInterval(interval);
ble.gap().clearAdvertisingPayload();
ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, BEACON_EDDYSTONE, sizeof(BEACON_EDDYSTONE));
// Construct TLM Frame in initial advertising.
uint8_t serviceData[SERVICE_DATA_MAX];
unsigned serviceDataLen = 0;
serviceData[serviceDataLen++] = BEACON_EDDYSTONE[0];
serviceData[serviceDataLen++] = BEACON_EDDYSTONE[1];
serviceDataLen += constructTLMFrame(serviceData + serviceDataLen, SERVICE_DATA_MAX);
ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, serviceData, serviceDataLen);
ble.gap().startAdvertising();
ble.gap().onRadioNotification(this, &EddystoneService::radioNotificationCallback);
timeSinceBootTick.attach(this, &EddystoneService::tsbCallback, 0.1); // increment the TimeSinceBoot ticker every 0.1s
}
/*
* Update the TLM frame battery voltage value
* @param[in] voltagemv Voltage to update the TLM field battery voltage with (in mV)
* @return nothing
*/
void updateTlmBatteryVoltage(uint16_t voltagemv) {
TlmBatteryVoltage = voltagemv;
}
/*
* Update the TLM frame beacon temperature
* @param[in] temp Temperature of beacon (in 8.8fpn)
* @return nothing
*/
void updateTlmBeaconTemp(uint16_t temp) {
TlmBeaconTemp = temp;
}
/*
* Update the TLM frame PDU Count field
* @param[in] pduCount Number of Advertising frames sent since power-up
*/
void updateTlmPduCount(uint32_t pduCount) {
TlmPduCount = pduCount;
}
/*
* Update the TLM frame Time since boot in 0.1s increments
* @param[in] timeSinceBoot Time since boot in 0.1s increments
*/
void updateTlmTimeSinceBoot(uint32_t timeSinceBoot) {
TlmTimeSinceBoot = timeSinceBoot;
}
protected:
/*
* callback function, called every 0.1s, increments the TimeSinceBoot field in the TLM frame
*/
virtual void tsbCallback(void) {
TlmTimeSinceBoot++;
}
private:
/*
* Set Eddystone UID Frame information.
*
* @param[in] power TX Power in dB measured at 0 meters from the device. Range of -100 to +20 dB.
* @param namespaceID 10B namespace ID
* @param instanceID 6B instance ID
* @param RFU 2B of RFU, initialized to 0x0000 and not broadcast, included for future reference.
*/
void setUIDFrameData(int8_t power, const UIDNamespaceID_t namespaceID, const UIDInstanceID_t instanceID, uint16_t RFU = 0x0000) {
if (power > 20) {
power = 20;
}
if (power < -100) {
power = -100;
}
defaultUidPower = power;
memcpy(defaultUidNamespaceID, namespaceID, UID_NAMESPACEID_SIZE);
memcpy(defaultUidInstanceID, instanceID, UID_INSTANCEID_SIZE);
uidRFU = (uint16_t)RFU; // this is probably bad form, but it doesn't really matter yet.
}
/**
* Construct UID frame from private variables
*
* @param[in,out] data
* pointer to array to store constructed frame in
* @param[in] maxSize
* number of bytes left in array, effectively how much empty space is available to write to
*
* @return number of bytes used. negative number indicates error message.
*/
int constructUIDFrame(uint8_t *data, uint8_t maxSize) {
if (maxSize < FRAME_SIZE_UID) {
return -1;
}
unsigned index = 0;
data[index++] = FRAME_TYPE_UID; // 1B Type
if (defaultUidPower > 20) { // enforce range of valid values.
defaultUidPower = 20;
}
if (defaultUidPower < -100) {
defaultUidPower = -100;
}
data[index++] = defaultUidPower; // 1B Power @ 0meter
for (size_t x = 0; x < UID_NAMESPACEID_SIZE; x++) { // 10B Namespce ID
data[index++] = defaultUidNamespaceID[x];
}
for (size_t x = 0; x< UID_INSTANCEID_SIZE; x++) { // 6B Instance ID
data[index++] = defaultUidInstanceID[x];
}
if (uidRFU) { // 2B RFU, include if non-zero, otherwise ignore
data[index++] = (uint8_t)(uidRFU >> 0);
data[index++] = (uint8_t)(uidRFU >> 8);
}
return index;
}
/*
* Update advertising data
* @return true on success, false on failure
*/
bool updateAdvPacket(const uint8_t serviceData[], unsigned serviceDataLen) {
return (ble.gap().updateAdvertisingPayload(GapAdvertisingData::SERVICE_DATA, serviceData, serviceDataLen) == BLE_ERROR_NONE);
}
/*
* Set Eddystone URL Frame information.
* @param[in] power TX Power in dB measured at 0 meters from the device.
* @param url URL to encode
* @return false on success, true on failure.
*/
bool setURLFrameData(int8_t power, const char *url) {
defaultUrlPower = power;
encodeURL(url, defaultUriData, defaultUriDataLength); // encode URL to URL Formatting
if (defaultUriDataLength > URI_DATA_MAX) {
return true; // error, URL is too big
}
return false;
}
/**
* Construct URL frame from private variables.
*
* @param[in,out] data
* pointer to array to store constructed frame in
* @param[in] maxSize
* number of bytes left in array, effectively how much empty space is available to write to.
*
* @return number of bytes used. negative number indicates error message.
*/
int constructURLFrame(uint8_t *data, uint8_t maxSize) {
if (maxSize < (1 + 1 + defaultUriDataLength)) {
return -1;
}
unsigned index = 0;
data[index++] = FRAME_TYPE_URL; // 1B Type
data[index++] = defaultUrlPower; // 1B TX Power
for (size_t x = 0; x < defaultUriDataLength; x++) { // 18B of URL Prefix + encoded URL
data[index++] = defaultUriData[x];
}
return index;
}
/*
* Set Eddystone TLM Frame information.
* @param[in] Version of the TLM beacon data format
* @param batteryVoltage in millivolts
* @param beaconTemp in 8.8 floating point notation
*
*/
void setTLMFrameData(uint8_t version, uint16_t batteryVoltage, uint16_t beaconTemp, uint32_t pduCount = 0, uint32_t timeSinceBoot = 0) {
TlmVersion = version;
TlmBatteryVoltage = batteryVoltage;
TlmBeaconTemp = beaconTemp;
TlmPduCount = pduCount; // reset
TlmTimeSinceBoot = timeSinceBoot; // reset
}
/*
* Construct TLM frame from private variables
* @param[in,out] data
* pointer to array to store constructed frame in
* @param[in] maxSize
* number of bytes left in array, effectively how much empty space is available to write to.
*
* @return number of bytes used. negative number indicates error message.
*/
int constructTLMFrame(uint8_t *data, uint8_t maxSize) {
if (maxSize < FRAME_SIZE_TLM) {
return -1;
}
unsigned index = 0;
data[index++] = FRAME_TYPE_TLM; // Eddystone frame type = Telemetry
data[index++] = TlmVersion; // TLM Version Number
data[index++] = (uint8_t)(TlmBatteryVoltage >> 8); // Battery Voltage[0]
data[index++] = (uint8_t)(TlmBatteryVoltage >> 0); // Battery Voltage[1]
data[index++] = (uint8_t)(TlmBeaconTemp >> 8); // Beacon Temp[0]
data[index++] = (uint8_t)(TlmBeaconTemp >> 0); // Beacon Temp[1]
data[index++] = (uint8_t)(TlmPduCount >> 24); // PDU Count [0]
data[index++] = (uint8_t)(TlmPduCount >> 16); // PDU Count [1]
data[index++] = (uint8_t)(TlmPduCount >> 8); // PDU Count [2]
data[index++] = (uint8_t)(TlmPduCount >> 0); // PDU Count [3]
data[index++] = (uint8_t)(TlmTimeSinceBoot >> 24); // Time Since Boot [0]
data[index++] = (uint8_t)(TlmTimeSinceBoot >> 16); // Time Since Boot [1]
data[index++] = (uint8_t)(TlmTimeSinceBoot >> 8); // Time Since Boot [2]
data[index++] = (uint8_t)(TlmTimeSinceBoot >> 0); // Time Since Boot [3]
return index;
}
/*
* State machine for switching out frames.
* This function is called by the radioNotificationCallback when a frame needs to get swapped out.
* This function exists because of time constraints in the radioNotificationCallback, so it is effectively
* broken up into two functions.
*/
void swapOutFrames(void) {
uint8_t serviceData[SERVICE_DATA_MAX];
//hard code in the Eddystone UUID
unsigned serviceDataLen = 0;
serviceData[serviceDataLen++] = BEACON_EDDYSTONE[0];
serviceData[serviceDataLen++] = BEACON_EDDYSTONE[1];
// if certain frames are not enabled, then skip them. Worst case TLM is always enabled
switch (frameIndex) {
case 1:
// URL Frame
if (urlIsSet) {
INFO("Swapping in URL Frame: Power: %d", defaultUrlPower);
serviceDataLen += constructURLFrame(serviceData + serviceDataLen, 20);
DBG("\t Swapping in URL Frame: len=%d ", serviceDataLen);
updateAdvPacket(serviceData, serviceDataLen);
switchFlag = false;
frameIndex++;
break;
}
case 2:
// UID Frame
if (uidIsSet) {
INFO("Swapping in UID Frame: Power: %d", defaultUidPower);
serviceDataLen += constructUIDFrame(serviceData + serviceDataLen, 20);
DBG("\t Swapping in UID Frame: len=%d", serviceDataLen);
updateAdvPacket(serviceData, serviceDataLen);
switchFlag = false;
frameIndex++;
break;
}
default:
// TLM frame
INFO("Swapping in TLM Frame: version=%x, Batt=%d, Temp = %d, PDUCnt = %d, TimeSinceBoot=%d",
TlmVersion,
TlmBatteryVoltage,
TlmBeaconTemp,
TlmPduCount,
TlmTimeSinceBoot);
serviceDataLen += constructTLMFrame(serviceData + serviceDataLen, 20);
DBG("\t Swapping in TLM Frame: len=%d", serviceDataLen);
updateAdvPacket(serviceData, serviceDataLen);
frameIndex++;
break;
}
}
/*
* Callback from onRadioNotification(), used to update the PDUCounter and process next state.
*/
void radioNotificationCallback(bool radioActive) {
static const unsigned EDDYSTONE_SWAPFRAME_DELAYMS = 1;
// Update PDUCount
TlmPduCount++;
frameIndex = frameIndex % NUM_FRAMETYPES;
if (!radioActive) { // false just after a frame is sent
// state machine to control which packet is being sent
switch (frameIndex) {
case 0: // TLM Frame
switchFrame.attach_us(this, &EddystoneService::swapOutFrames, EDDYSTONE_SWAPFRAME_DELAYMS);
switchFlag = true;
break;
case 1: // URL Frame
// switch out packets
if (switchFlag) {
switchFrame.attach_us(this, &EddystoneService::swapOutFrames, EDDYSTONE_SWAPFRAME_DELAYMS);
switchFlag = false;
} else {
if ((TlmPduCount % 10) == 0) { // every 10 adv packets switch the frame
switchFlag = true;
}
}
break;
case 2: // UIDFrame
// switch out packets
if (switchFlag) {
switchFrame.attach_us(this, &EddystoneService::swapOutFrames, EDDYSTONE_SWAPFRAME_DELAYMS);
switchFlag = false;
} else {
if ((TlmPduCount % 10) == 0) { // every 10 adv packets switch the frame
switchFlag = true;
}
}
break;
}
}
}
private:
BLEDevice &ble;
Ticker timeSinceBootTick;
Timeout switchFrame;
// Default value that is restored on reset
size_t defaultUriDataLength;
UriData_t defaultUriData;
UIDNamespaceID_t defaultUidNamespaceID;
UIDInstanceID_t defaultUidInstanceID;
int8_t defaultUidPower;
int8_t defaultUrlPower;
unsigned frameIndex;
uint16_t uidRFU;
bool uidIsSet;
bool urlIsSet;
bool switchFlag;
// Private Variables for Telemetry Data
uint8_t TlmVersion;
volatile uint16_t TlmBatteryVoltage;
volatile uint16_t TlmBeaconTemp;
volatile uint32_t TlmPduCount;
volatile uint32_t TlmTimeSinceBoot;
public:
/*
* Encode a human-readable URI into the binary format defined by URIBeacon spec (https://github.com/google/uribeacon/tree/master/specification).
*/
static void encodeURL(const char *uriDataIn, UriData_t uriDataOut, size_t &sizeofURIDataOut) {
const char *prefixes[] = {
"http://www.",
"https://www.",
"http://",
"https://",
};
const size_t NUM_PREFIXES = sizeof(prefixes) / sizeof(char *);
const char *suffixes[] = {
".com/",
".org/",
".edu/",
".net/",
".info/",
".biz/",
".gov/",
".com",
".org",
".edu",
".net",
".info",
".biz",
".gov"
};
const size_t NUM_SUFFIXES = sizeof(suffixes) / sizeof(char *);
sizeofURIDataOut = 0;
memset(uriDataOut, 0, sizeof(UriData_t));
if ((uriDataIn == NULL) || (strlen(uriDataIn) == 0)) {
return;
}
/*
* handle prefix
*/
for (unsigned i = 0; i < NUM_PREFIXES; i++) {
size_t prefixLen = strlen(prefixes[i]);
if (strncmp(uriDataIn, prefixes[i], prefixLen) == 0) {
uriDataOut[sizeofURIDataOut++] = i;
uriDataIn += prefixLen;
break;
}
}
/*
* handle suffixes
*/
while (*uriDataIn && (sizeofURIDataOut < URI_DATA_MAX)) {
/* check for suffix match */
unsigned i;
for (i = 0; i < NUM_SUFFIXES; i++) {
size_t suffixLen = strlen(suffixes[i]);
if (strncmp(uriDataIn, suffixes[i], suffixLen) == 0) {
uriDataOut[sizeofURIDataOut++] = i;
uriDataIn += suffixLen;
break; /* from the for loop for checking against suffixes */
}
}
/* This is the default case where we've got an ordinary character which doesn't match a suffix. */
if (i == NUM_SUFFIXES) {
uriDataOut[sizeofURIDataOut++] = *uriDataIn;
++uriDataIn;
}
}
}
};
#endif // SERVICES_EDDYSTONEBEACON_H_