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GATT Characteristics

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hedy edited this page Dec 29, 2016 · 3 revisions

SIG-defined GATT Characteristics

A Characteristic is a container of the user data. It is defined by

  • UUID: a 16-bit number defined by SIG to represent a attribute
  • Value: actual value of the user data which is a piece of bytes

Value is a logical value and ble-packet can parse it into an object according to particular rules. The following table gives the fields and their data types of a parsed object.

The 'flags' field tells how to parse the Value, and the rule is given with something like tempF(bit0) and tempC(!bit0).

  • tempF(bit0) means that if bit0 of 'flags' is 1, the field tempF will be picked and parsed.
  • tempC(!bit0) means that if bit0 of 'flags' is 0, the field tempC will be picked and parsed.
  • medicationL(bit4 & bit5) means that if bit4 and bit5 of 'flags' are both 1, the field medicationL will be picked and parsed.
  • Here is an example of the parsed result object of a Characteristic with UUID 0x2a1c
{   // Result object of UUID 0x2a1c 
    flags: 2,       // bit0 = 0, bit1 = 1, bit2 = 0
    tempC: 21.5,    // tempC(!bit0)
    year: 2015,     // year(bit1)
    month: 12,      // month(bit1)
    day: 25,        // day(bit1)
    hours: 21,      // hours(bit1)
    minutes: 36,    // minutes(bit1) 
    seconds: 12     // seconds(bit1) 
}

Note:

  • A field type of list(type) indicates that value of this field is an array and (type) tells the data type of each entry in it.
{   // Result object of UUID 0x2a22, Field type: list(uint8)
    bootKeyboardInputReport: [1, 2, 3]
}
  • ble-packet can not build and parse the packet comes with the following commands, since the input to each command is probably not an eligible Characteristic Value.
    • 'ATT_ReadBlobRsp', 'ATT_PrepareWriteReq', 'ATT_PrepareWriteRsp', 'GATT_WriteLongCharValue', 'GATT_ReliableWrites'
  • ble-packet can not build and parse the Characteristic Value comes with the following UUIDs, since there are fields with variable length, optional, or unknown.
    • '0x2a2a', '0x2a55', '0x2a5a', '0x2a63', '0x2a64', '0x2a66', '0x2a6b', '0x2aa4', '0x2aa7', '0x2aa9', '0x2aaa', '0x2aab', '0x2aac'

UUID Field Names Filed types
0x2a00 name string
0x2a01 category uint16
0x2a02 flag boolean
0x2a03 addr addr6
0x2a04 minConnInterval, maxConnInterval, latency, timeout uint16, uint16, uint16, uint16
0x2a05 startHandle, endHandle uint16, uint16
0x2a06 alertLevel uint8
0x2a07 txPower int8
0x2a08 year, month, day, hours, minutes, seconds uint16, uint8, uint8, uint8, uint8, uint8
0x2a09 dayOfWeek uint8
0x2a0a year, month, day, hours, minutes, seconds, dayOfWeek uint16, uint8, uint8, uint8, uint8, uint8, uint8
0x2a0c year, month, day, hours, minutes, seconds, dayOfWeek, fractions256 uint16, uint8, uint8, uint8, uint8, uint8, uint8, uint8
0x2a0d dstOffset uint8
0x2a0e timeZone int8
0x2a0f timeZone, dstOffset int8, uint8
0x2a11 year, month, day, hours, minutes, seconds, dstOffset uint16, uint8, uint8, uint8, uint8, uint8, uint8
0x2a12 accuracy uint8
0x2a13 timeSource uint8
0x2a14 source, accuracy, daySinceUpdate, hourSinceUpdate uint8, uint8, uint8, uint8
0x2a16 timeUpdateCtrl uint8
0x2a17 currentState, result uint8, uint8
0x2a18 flags, sequenceNum, year, month, day, hours, minutes, seconds, timeOffset(bit0), glucoseKg(bit1 & !bit2), glucoseMol(bit1 & bit2), type(bit2), sampleLocation(bit2), sensorStatus(bit3) uint8, uint16, uint16, uint8, uint8, uint8, uint8, uint8,
0x2a19 level uint8
0x2a1c flags, tempC(!bit0), tempF(bit0), year(bit1), month(bit1), day(bit1), hours(bit1), minutes(bit1), seconds(bit1), tempType(bit2) uint8, float, float, uint16, uint8, uint8, uint8, uint8, uint8, uint8
0x2a1d tempTextDesc uint8
0x2a1e flags, tempC(!bit0), tempF(bit0), year(bit1), month(bit1), day(bit1), hours(bit1), minutes(bit1), seconds(bit1), tempType(bit2) uint8, float, float, uint16, uint8, uint8, uint8, uint8, uint8, uint8
0x2a21 measureInterval uint16
0x2a22 bootKeyboardInput list(uint8)
0x2a23 manufacturerID, organizationallyUID addr5, addr3
0x2a24 modelNum string
0x2a25 serialNum string
0x2a26 firmwareRev string
0x2a27 hardwareRev string
0x2a28 softwareRev string
0x2a29 manufacturerName string
0x2a2b year, month, day, hours, minutes, seconds, dayOfWeek, fractions256, adjustReason uint16, uint8, uint8, uint8, uint8, uint8, uint8, uint8, uint8
0x2a2c magneticDeclination uint16
0x2a31 scanRefresh uint8
0x2a32 bootKeyboardOutput list(uint8)
0x2a33 bootMouseInput list(uint8)
0x2a34 flags, sequenceNum, extendedFlags(bit7), carbohydrateID(bit0), carbohydrate(bit0), meal(bit1), tester(bit1), health(bit2), exerciseDuration(bit3), exerciseIntensity(bit3), medicationID(bit4), medicationKg(bit4 & !bit5), medicationL(bit4 & bit5), hbA1c(bit6) uint8, uint16, uint8, uint8, sfloat, uint8, nibble, nibble, uint16, uint8, uint8, sfloat, sfloat, sfloat
0x2a35 flags, systolicMmHg(!bit0), diastolicMmHg(!bit0), arterialPresMmHg(!bit0), systolicKpa(bit0), diastolicKpa(bit0), arterialPresKpa(bit0), year(bit1), month(bit1), day(bit1), hours(bit1), minutes(bit1), seconds(bit1), pulseRate(bit2), userID(bit3), status(bit4) uint8, sfloat, sfloat, sfloat, sfloat, sfloat, sfloat, uint16, uint8, uint8, uint8, uint8, uint8, sfloat, uint8, uint16
0x2a36 flags, systolicMmHg(!bit0), diastolicMmHg(!bit0), arterialPresMmHg(!bit0), systolicKpa(bit0), diastolicKpa(bit0), arterialPresKpa(bit0), year(bit1), month(bit1), day(bit1), hours(bit1), minutes(bit1), seconds(bit1), pulseRate(bit2), userID(bit3), status(bit4) uint8, sfloat, sfloat, sfloat, sfloat, sfloat, sfloat, uint16, uint8, uint8, uint8, uint8, uint8, sfloat, uint8, uint16
0x2a37 flags, heartRate8(!bit0), heartRate16(bit0), energyExpended(bit3), rrInterval(bit4) uint8, uint8, uint16, uint16, uint16
0x2a38 bodySensorLocation uint8
0x2a39 heartRateCtrl uint8
0x2a3f alertStatus uint8
0x2a40 ringerCtrlPoint uint8
0x2a41 ringerSet uint8
0x2a42 categoryIDBitMask0, categoryIDBitMask1 uint8, uint8
0x2a43 categoryID uint8
0x2a44 commID, categoryID uint8, uint8
0x2a45 categoryID, unreadCount uint8, uint8
0x2a46 categoryID, newAlert, textStringInfo uint8, uint8, string
0x2a47 categoryIDBitMask0, categoryIDBitMask1 uint8, uint8
0x2a48 categoryIDBitMask0, categoryIDBitMask1 uint8, uint8
0x2a49 feature uint16
0x2a4a bcdHID, bCountryCode, flags uint16, uint8, uint8
0x2a4b reportMap list(uint8)
0x2a4c hidCtrl uint8
0x2a4d report list(uint8)
0x2a4e protocolMode uint8
0x2a4f leScanInterval, leScanWindow uint16, uint16
0x2a50 vendorIDSource, vendorID, productID, productVersion uint8, uint16, uint16, uint16
0x2a51 feature uint16
0x2a52 opcode, operand uint8, uint8, uint8
0x2a53 flags, speed, cadence, strideLength(bit0), totalDist(bit1) uint8, uint16, uint8, uint16, uint32
0x2a54 feature uint16
0x2a56 digital uint8
0x2a58 analog uint16
0x2a5b flags, cumulativeWheelRev(bit0), lastWheelEventTime(bit0), cumulativeCrankRev(bit1), lastCrankEventTime(bit1) uint8, uint32, uint16, uint16, uint16
0x2a5c feature uint16
0x2a5d sensorLocation uint8
0x2a5e flags, spotCheckSpO2, spotCheckPr, year(bit0), month(bit0), day(bit0), hours(bit0), minutes(bit0), seconds(bit0), measureStatus(bit1), deviceAndSensorStatus(bit2), pulseAmpIndex(bit3) uint8, sfloat, sfloat, uint16, uint8, uint8, uint8, uint8, uint8, uint16, uint24, sfloat
0x2a5f flags, normalSpO2, normalPR, fastSpO2(bit0), fastPR(bit0), slowSpO2(bit1), slowPR(bit1), measureStatus(bit2), deviceAndSensorStatus(bit3), pulseAmpIndex(bit4) uint8, sfloat, sfloat, sfloat, sfloat, sfloat, sfloat, uint16, uint24, sfloat
0x2a65 feature uint32
0x2a67 flags, instantSpeed(bit0), totalDist(bit1), latitude(bit2), longitude(bit2), elevation(bit3), heading(bit4), rollingTime(bit5), year(bit6), month(bit6), day(bit6), hours(bit6), minutes(bit6), seconds(bit6) uint8, uint16, uint24, int32, int32, int24, uint16, uint8, uint16, uint8, uint8, uint8, uint8, uint8
0x2a68 flags, bearing, heading, remainingDist(bit0), remainingVertDist(bit1), year(bit2), month(bit2), day(bit2), hours(bit2), minutes(bit2), seconds(bit2) uint8, uint16, uint16, uint24, int24, uint16, uint8, uint8, uint8, uint8, uint8
0x2a69 flags, beaconsInSolution(bit0), beaconsInView(bit1), timeToFirstFix(bit2), ehpe(bit3), evpe(bit4), hdop(bit5), vdop(bit6) uint8, uint8, uint8, uint16, uint32, uint32, uint8, uint8
0x2a6a feature uint32
0x2a6c elevation int24
0x2a6d pressure uint32
0x2a6e temp int16
0x2a6f humidity uint16
0x2a70 trueWindSpeed uint16
0x2a71 trueWindDirection uint16
0x2a72 apparentWindSpeed uint16
0x2a73 apparentWindDirection uint16
0x2a74 gustFactor uint8
0x2a75 pollenConc uint24
0x2a76 uvIndex uint8
0x2a77 irradiance uint16
0x2a78 rainfall uint16
0x2a79 windChill int8
0x2a7a heatIndex int8
0x2a7b dewPoint int8
0x2a7d flag, uuid uint16, uuid
0x2a7e lowerLimit uint8
0x2a7f threshold uint8
0x2a80 age uint8
0x2a81 lowerLimit uint8
0x2a82 upperLimit uint8
0x2a83 threshold uint8
0x2a84 upperLimit uint8
0x2a85 year, month, day uint16, uint8, uint8
0x2a86 year, month, day uint16, uint8, uint8
0x2a87 emailAddr string
0x2a88 lowerLimit uint8
0x2a89 upperLimit uint8
0x2a8a firstName string
0x2a8b veryLightAndLight, lightAndModerate, moderateAndHard, hardAndMax uint8, uint8, uint8, uint8
0x2a8c gender uint8
0x2a8d heartRateMax uint8
0x2a8e height uint16
0x2a8f hipCircumference uint16
0x2a90 lastName string
0x2a91 maxHeartRate uint8
0x2a92 restingHeartRate uint8
0x2a93 sportType uint8
0x2a94 lightAndModerate, moderateAndHard uint8, uint8
0x2a95 fatburnAndFitness uint8
0x2a96 vo2Max uint8
0x2a97 waistCir uint16
0x2a98 weight uint16
0x2a99 changeIncrement uint32
0x2a9a userIndex uint8
0x2a9b feature uint32
0x2a9c flags, bodyFatPercent, year(bit1), month(bit1), day(bit1), hours(bit1), minutes(bit1), seconds(bit1), userID(bit2), basalMetabolism(bit3), musclePercent(bit4), muscleMassKg(!bit0 & bit5), muscleMassPounds(bit0 & bit5), fatFreeMassKg(!bit0 & bit6), fatFreeMassPounds(bit0 & bit6), softLeanMassKg(!bit0 & bit7), softLeanMassPounds(bit0 & bit7), bodyWaterMassKg(!bit0 & bit8), bodyWaterMassPounds(bit0 & bit8), impedance(bit9), weightKg(!bit0 & bit10), weightPounds(bit0 & bit10), heightMeters(!bit0 & bit11), heightInches(bit0 & bit11) uint16, uint16, uint16, uint8, uint8, uint8, uint8, uint8, uint8, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16
0x2a9d flags, weightSI(!bit0), weightImperial(bit0), year(bit1), month(bit1), day(bit1), hours(bit1), minutes(bit1), seconds(bit1), userID(bit2), bmi(bit3), heightSI(!bit0 & bit3), heightImperial(bit0 & bit3) uint8, uint16, uint16, uint16, uint8, uint8, uint8, uint8, uint8, uint8, uint16, uint16, uint16
0x2a9e feature uint32
0x2a9f opcode, parameter uint8, buffer
0x2aa0 xAxis, yAxis int16, int16
0x2aa1 xAxis, yAxis, zAxis int16, int16, int16
0x2aa2 language string
0x2aa3 barometricPresTrend uint8
0x2aa5 feature uint24
0x2aa6 addrResolutionSup uint8
0x2aa8 feature, type, sampleLocation, e2eCrc uint24, nibble, nibble, uint16
0x2aad indoorPosition uint8
0x2aae latitude int32
0x2aaf longitude int32
0x2ab0 localNorthCoordinate int16
0x2ab1 localEastCoordinate int16
0x2ab2 floorNum uint8
0x2ab3 altitude uint16
0x2ab4 uncertainty uint8
0x2ab5 locationName string
0x2ab6 uri string
0x2ab7 httpHeaders string
0x2ab8 statusCode, dataStatus uint16, uint8
0x2ab9 httpEntityBody string
0x2aba opcode uint8
0x2abb httpsSecurity boolean
0x2abc opcode, organizationID, parameter uint8, uint8, buffer
0x2abd oacpFeatures, olcpFeatures uint32, uint32
0x2abe objectName string
0x2abf objectType uuid

1. Overview
2. GATT Specifications
3. Installation
4. Usage
5. APIs

6. Appendix

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