Merge pull request #29 from combustion-inc/feature/uart_crc

CRC for UART messages and isConnectable flag

Sources/CombustionBLE/BleManager.swift

@@ -36,7 +36,7 @@ protocol BleManagerDelegate: AnyObject {
     func didDisconnectFrom(identifier: UUID)
     func handleSetIDResponse(identifier: UUID, success: Bool)
     func handleSetColorResponse(identifier: UUID, success: Bool)
-    func updateDeviceWithAdvertising(advertising: AdvertisingData, rssi: NSNumber, identifier: UUID)
+    func updateDeviceWithAdvertising(advertising: AdvertisingData, isConnectable: Bool, rssi: NSNumber, identifier: UUID)
     func updateDeviceWithLogResponse(identifier: UUID, logResponse: LogResponse)
     func updateDeviceWithSessionInformation(identifier: UUID, sessionInformation: SessionInformation)
     func updateDeviceWithStatus(identifier: UUID, status: DeviceStatus)
@@ -137,6 +137,7 @@ extension BleManager: CBCentralManagerDelegate{
                                advertisementData: [String : Any], rssi RSSI: NSNumber) {
 
         let manufatureData: Data = advertisementData[CBAdvertisementDataManufacturerDataKey] as? Data ?? Data()
+        let isConnectable = advertisementData[CBAdvertisementDataIsConnectable] as? Bool ?? false
 
         if let advData = AdvertisingData(fromData: manufatureData) {
             // For now, only add probes.
@@ -145,7 +146,10 @@ extension BleManager: CBCentralManagerDelegate{
                 // Store peripheral reference for later use
                 peripherals.insert(peripheral)
 
-                delegate?.updateDeviceWithAdvertising(advertising: advData, rssi: RSSI, identifier: peripheral.identifier)
+                delegate?.updateDeviceWithAdvertising(advertising: advData,
+                                                      isConnectable: isConnectable,
+                                                      rssi: RSSI,
+                                                      identifier: peripheral.identifier)
             } else {
                 // print("Ignoring device with type \(advData.type)")
             }

Sources/CombustionBLE/Device.swift

@@ -55,6 +55,9 @@ public class Device : ObservableObject {
     /// Current connection state of device
     @Published public internal(set) var connectionState: ConnectionState = .disconnected
 
+    /// Connectable flag set in advertising packet
+    @Published public internal(set) var isConnectable = false
+
     /// Signal strength to device
     @Published public internal(set) var rssi: Int
 
@@ -103,6 +106,12 @@ public class Device : ObservableObject {
 
     func updateDeviceStale() {
         stale = Date().timeIntervalSince(lastUpdateTime) > Constants.STALE_TIMEOUT
+
+
+        // If device data is stale, assume its not longer connectable
+        if(stale) {
+            isConnectable = false
+        }
     }
 
     public func isDFURunning() -> Bool {
@@ -126,7 +135,6 @@ extension Device {
     /// Attempt to connect to the device.
     public func connect() {
         // Mark that we should maintain a connection to this device.
-        // TODO - this doesn't seem to be propagating back to the UI??
         maintainingConnection = true
 
         if(connectionState != .connected) {

Sources/CombustionBLE/DeviceManager.swift

@@ -236,14 +236,14 @@ extension DeviceManager : BleManagerDelegate {
         }
     }
 
-    func updateDeviceWithAdvertising(advertising: AdvertisingData, rssi: NSNumber, identifier: UUID) {
+    func updateDeviceWithAdvertising(advertising: AdvertisingData, isConnectable: Bool, rssi: NSNumber, identifier: UUID) {
         if devices[identifier.uuidString] != nil {
             if let probe = devices[identifier.uuidString] as? Probe {
-                probe.updateWithAdvertising(advertising, RSSI: rssi)
+                probe.updateWithAdvertising(advertising, isConnectable: isConnectable, RSSI: rssi)
             }
         }
         else {
-            let device = Probe(advertising, RSSI: rssi, identifier: identifier)
+            let device = Probe(advertising, isConnectable: isConnectable, RSSI: rssi, identifier: identifier)
             addDevice(device: device)
         }
     }

Sources/CombustionBLE/Probe.swift

@@ -70,14 +70,14 @@ public class Probe : Device {
     /// Time at which probe instant read was last updated
     internal var lastInstantRead: Date?
 
-    public init(_ advertising: AdvertisingData, RSSI: NSNumber, identifier: UUID) {
+    public init(_ advertising: AdvertisingData, isConnectable: Bool, RSSI: NSNumber, identifier: UUID) {
         serialNumber = advertising.serialNumber
         id = advertising.id
         color = advertising.color
 
         super.init(identifier: identifier, RSSI: RSSI)
 
-        updateWithAdvertising(advertising, RSSI: RSSI)
+        updateWithAdvertising(advertising, isConnectable: isConnectable, RSSI: RSSI)
     }
 
     override func updateConnectionState(_ state: ConnectionState) {
@@ -108,21 +108,29 @@ extension Probe {
     }
 
 
-    func updateWithAdvertising(_ advertising: AdvertisingData, RSSI: NSNumber) {
-        if(advertising.mode == .Normal) {
-            currentTemperatures = advertising.temperatures
-        }
-        else if(advertising.mode == .InstantRead ){
-            updateInstantRead(advertising.temperatures.values[0])
-        }
+    func updateWithAdvertising(_ advertising: AdvertisingData, isConnectable: Bool, RSSI: NSNumber) {
+        // Always update probe RSSI and isConnectable flag
+        self.rssi = RSSI.intValue
+        self.isConnectable = isConnectable
 
-        rssi = RSSI.intValue
-
-        id = advertising.id
-        color = advertising.color
-        batteryStatus = advertising.batteryStatus
-
-        lastUpdateTime = Date()
+        // Only update rest of data if not connected to probe.  Otherwise, rely on status
+        // notifications to update data
+        if(connectionState != .connected)
+        {
+            if(advertising.mode == .Normal) {
+                currentTemperatures = advertising.temperatures
+            }
+            else if(advertising.mode == .InstantRead ){
+                updateInstantRead(advertising.temperatures.values[0])
+            }
+
+
+            id = advertising.id
+            color = advertising.color
+            batteryStatus = advertising.batteryStatus
+
+            lastUpdateTime = Date()
+        }
     }
 
     /// Updates the Device based on newly-received DeviceStatus message. Requests missing records.

Sources/CombustionBLE/SimulatedProbe.swift

@@ -31,7 +31,7 @@ class SimulatedProbe: Probe {
     init() {
         let advertising = AdvertisingData(fakeSerial: UInt32.random(in: 0 ..< UINT32_MAX),
                                           fakeTemperatures: ProbeTemperatures.withRandomData())
-        super.init(advertising, RSSI: SimulatedProbe.randomeRSSI(), identifier: UUID())
+        super.init(advertising, isConnectable: true, RSSI: SimulatedProbe.randomeRSSI(), identifier: UUID())
 
         firmareVersion = "v1.2.3"
         hardwareRevision = "v0.31-A1"
@@ -64,7 +64,7 @@ class SimulatedProbe: Probe {
     private func updateFakeAdvertising() {
         let advertising = AdvertisingData(fakeSerial: UInt32.random(in: 0 ..< UINT32_MAX),
                                           fakeTemperatures: ProbeTemperatures.withRandomData())
-        updateWithAdvertising(advertising, RSSI: SimulatedProbe.randomeRSSI())
+        updateWithAdvertising(advertising, isConnectable: true, RSSI: SimulatedProbe.randomeRSSI())
     }
 
     private func updateFakeStatus() {

Sources/CombustionBLE/UART/LogRequest.swift

@@ -27,23 +27,15 @@ SOFTWARE.
 import Foundation
 
 class LogRequest: Request {
-    static let PAYLOAD_LENGTH: UInt8 = 8
-
     init(minSequence: UInt32, maxSequence: UInt32) {
-        super.init(payloadLength: LogRequest.PAYLOAD_LENGTH, type: .Log)
+        var payload = Data()
 
         var min = minSequence
-        let minData = Data(bytes: &min, count: MemoryLayout.size(ofValue: min))
-        self.data[Request.HEADER_SIZE + 0] = minData[0]
-        self.data[Request.HEADER_SIZE + 1] = minData[1]
-        self.data[Request.HEADER_SIZE + 2] = minData[2]
-        self.data[Request.HEADER_SIZE + 3] = minData[3]
+        payload.append(Data(bytes: &min, count: MemoryLayout.size(ofValue: min)))
 
         var max = maxSequence
-        let maxData = Data(bytes: &max, count: MemoryLayout.size(ofValue: max))
-        self.data[Request.HEADER_SIZE + 4] = maxData[0]
-        self.data[Request.HEADER_SIZE + 5] = maxData[1]
-        self.data[Request.HEADER_SIZE + 6] = maxData[2]
-        self.data[Request.HEADER_SIZE + 7] = maxData[3]
+        payload.append(Data(bytes: &max, count: MemoryLayout.size(ofValue: max)))
+
+        super.init(payload: payload, type: .Log)
     }
 }

Sources/CombustionBLE/UART/Request.swift

@@ -32,25 +32,35 @@ class Request {
     static let HEADER_SIZE = 6
 
     /// Contains message data.
-    var data: Data
+    var data = Data()
 
     /// Constructor for Request object.
     /// - parameter payloadLength: Length of payload of message
     /// - parameter type: Type of message
-    init(payloadLength: UInt8, type: MessageType) {
-        let messageSize = Request.HEADER_SIZE + Int(payloadLength)
-        data = Data(repeating: 0, count: messageSize)
+    init(payload: Data, type: MessageType) {
 
         // Sync Bytes { 0xCA, 0xFE }
-        data[0] = 0xCA
-        data[1] = 0xFE
+        data.append(0xCA)
+        data.append(0xFE)
 
-        // CRC : TODO
+        // Calculate CRC over Message Type, payload length, payload
+        var crcData = Data()
 
         // Message type
-        data[4] = type.rawValue
+        crcData.append(type.rawValue)
 
         // Payload length
-        data[5] = payloadLength
+        crcData.append(UInt8(payload.count))
+
+        // Payload
+        crcData.append(payload)
+
+        var crcValue = crcData.crc16ccitt()
+
+        // CRC
+        data.append(Data(bytes: &crcValue, count: MemoryLayout.size(ofValue: crcValue)))
+
+        // Message Type, payload length, payload
+        data.append(crcData)
     }
 }

Sources/CombustionBLE/UART/Response.swift

@@ -68,8 +68,6 @@ extension Response {
             return nil
         }
 
-        // CRC : TODO (bytes 2,3)
-
         // Message type
         let typeByte = data.subdata(in: 4..<5)
         let typeRaw = typeByte.withUnsafeBytes {
@@ -93,6 +91,23 @@ extension Response {
             $0.load(as: UInt8.self)
         }
 
+        // CRC
+        let crcBytes = data.subdata(in: 2..<4)
+        let crc = crcBytes.withUnsafeBytes {
+            $0.load(as: UInt16.self)
+        }
+
+        let crcDataLength = 3 + Int(payloadLength)
+        var crcData = data.dropFirst(4)
+        crcData = crcData.dropLast(crcData.count - crcDataLength)
+
+        let calculatedCRC = crcData.crc16ccitt()
+
+        guard crc == calculatedCRC else {
+            print("Response::fromData(): Invalid CRC")
+            return nil
+        }
+
         let responseLength = Int(payloadLength) + HEADER_LENGTH
 
         // Invalid number of bytes

Sources/CombustionBLE/UART/SessionInfo.swift

@@ -32,10 +32,8 @@ public struct SessionInformation {
 }
 
 class SessionInfoRequest: Request {
-    static let PAYLOAD_LENGTH: UInt8 = 0
-
     init() {
-        super.init(payloadLength: SessionInfoRequest.PAYLOAD_LENGTH, type: .SessionInfo)
+        super.init(payload: Data(), type: .SessionInfo)
     }
 }
 

Sources/CombustionBLE/UART/SetColor.swift

@@ -27,11 +27,11 @@ SOFTWARE.
 import Foundation
 
 class SetColorRequest: Request {
-    static let PAYLOAD_LENGTH: UInt8 = 1
-
     init(color: ProbeColor) {
-        super.init(payloadLength: SetColorRequest.PAYLOAD_LENGTH, type: .SetColor)
-        self.data[Request.HEADER_SIZE] = color.rawValue
+        var payload = Data()
+        payload.append(color.rawValue)
+
+        super.init(payload: payload, type: .SetColor)
     }
 }
 

Sources/CombustionBLE/UART/SetID.swift

@@ -27,11 +27,11 @@ SOFTWARE.
 import Foundation
 
 class SetIDRequest: Request {
-    static let PAYLOAD_LENGTH: UInt8 = 1
-
     init(id: ProbeID) {
-        super.init(payloadLength: SetIDRequest.PAYLOAD_LENGTH, type: .SetID)
-        self.data[Request.HEADER_SIZE] = id.rawValue
+        var payload = Data()
+        payload.append(id.rawValue)
+
+        super.init(payload: payload, type: .SetID)
     }
 }
 

Sources/CombustionBLE/Utilities/Data+CRC.swift

@@ -0,0 +1,46 @@
+//  Data+CRC.swift
+
+/*--
+MIT License
+
+Copyright (c) 2022 Combustion Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+--*/
+
+import Foundation
+
+extension Data {
+    func crc16ccitt() -> UInt16 {
+        var crc: UInt16 = 0xFFFF // initial value
+        let polynomial: UInt16 = 0x1021 // 0001 0000 0010 0001  (0, 5, 12)
+
+        self.forEach { (byte) in
+            for i in 0...7 {
+                let bit = (byte >> (7 - i) & 1) == 1
+                let c15 = (crc  >> (15)    & 1) == 1
+                crc = crc << 1
+                if (c15 != bit) {
+                    crc = crc ^ polynomial
+                }
+            }
+        }
+        return crc & 0xffff
+    }
+}