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SwiftOBD2 is a Swift package designed to simplify communication with vehicles using an ELM327 OBD2 adapter. It provides a straightforward and powerful interface for interacting with your vehicle's onboard diagnostics system, allowing you to retrieve real-time data and perform diagnostics. Sample App.

Requirements

• iOS 14.0+ / macOS 11.0+
• Xcode 13.0+
• Swift 5.0+

Key Features

• Connection Management:

  • Establishes connections to the OBD2 adapter via Bluetooth or Wi-Fi.
  • Handles the initialization of the adapter and the vehicle connection process.
  • Manages connection states (disconnected, connectedToAdapter, connectedToVehicle).Command Interface: Send and receive OBD2 commands for powerful interaction with your vehicle.

• Data Retrieval:

  • Supports requests for real-time vehicle data (RPM, speed, etc.) using standard OBD2 PIDs (Parameter IDs).
  • Provides functions to continuously poll and retrieve updated measurements.
  • Can get a list of supported PIDs from the vehicle.

• Diagnostics:

  • Retrieves and clears diagnostic trouble codes (DTCs).
  • Gets the overall status of the vehicle's onboard systems.Sensor Monitoring: Retrieve and view data from various vehicle sensors in real time.

• Adaptability and Configuration

  • Can switch between Bluetooth and Wi-Fi communication seamlessly.
  • Allows for testing and development with a demo mode.

Roadmap

• Connect to an OBD2 adapter via Bluetooth Low Energy (BLE)
• Retrieve error codes (DTCs) stored in the vehicle's OBD2 system
• Retrieve various OBD2 Parameter IDs (PIDs) for monitoring vehicle parameters
• Retrieve real-time vehicle data (RPM, speed, etc.) using standard OBD2 PIDs
• Get supported PIDs from the vehicle
• Clear error codes (DTCs) stored in the vehicle's OBD2 system
• Run tests on the OBD2 system
• Retrieve vehicle status since DTCs cleared
• Connect to an OBD2 adapter via WIFI
• Add support for custom PIDs

Setting Up a Project

1. Create a New Swift Project:

   • Open Xcode and start a new iOS project (You can use a simple "App" template).

2. Add the SwiftOBD2 Package:

   • In Xcode, navigate to File > Add Packages...
   • Enter this repository's URL: https://github.com/kkonteh97/SwiftOBD2/
   • Select the desired dependency rule (version, branch, or commit).

3. Permissions and Capabilities:

   • If your app will use Bluetooth, you need to request the appropriate permissions and capabilities:
     • Add NSBluetoothAlwaysUsageDescription to your Info.plist file with a brief description of why your app needs to use Bluetooth.
     • Navigate to the Signing & Capabilities tab in your project settings and add the Background Modes capability. Enable the Uses Bluetooth LE Accessories option.

Key Concepts

• SwiftUI & Combine: Your code leverages the SwiftUI framework for building the user interface and Combine for reactive handling of updates from the OBDService.
• OBDService: This is the core class within the SwiftOBD2 package. It handles communication with the OBD-II adapter and processes data from the vehicle.
• OBDServiceDelegate: This protocol is crucial for receiving updates about the connection state and other events from the OBDService.
• OBDCommand: These represent specific requests you can make to the vehicle's ECU (Engine Control Unit) for data.

Usage

1. Import and Setup
   • Begin by importing the necessary modules:

import SwiftUI
import SwiftOBD2
import Combine

2. ViewModel

   • Create a ViewModel class that conforms to the ObservableObject protocol. This allows your SwiftUI views to observe changes in the ViewModel.
   • Inside the ViewModel:
     • Define a @Published property measurements to store the collected data.
     • Initialize an OBDService instance, setting the desired connection type (e.g., Bluetooth, Wi-Fi).

3. Connection Handling

   • Implement the connectionStateChanged method from the OBDServiceDelegate protocol. Update the UI based on connection state changes (disconnected, connected, etc.) or handle any necessary logic.

4. Starting the Connection

   • Create a startConnection function (ideally using async/await) to initiate the connection process with the OBD-II adapter. The OBDService's startConnection method will return useful OBDInfo about the vehicle. Like the Supported PIDs, Protocol, etc.

5. Stopping the Connection

   • Create a stopConnection function to cleanly disconnect the service.

6. Retrieving Information

   • Use the OBDService's methods to retrieve data from the vehicle, such as getting the vehicle's status, scanning for trouble codes, or requesting specific PIDs.
     • getTroubleCodes: Retrieve diagnostic trouble codes (DTCs) from the vehicle's OBD-II system.
     • getStatus: Retrieves Status since DTCs cleared.

7. Continuous Updates

   • Use the startContinuousUpdates method to continuously poll and retrieve updated measurements from the vehicle. This method returns a Combine publisher that you can subscribe to for updates.
   • Can also add PIDs to the continuous updates using the addPID method.

Code Example

class ViewModel: ObservableObject {
    @Published var measurements: [OBDCommand: MeasurementResult] = [:]
    @Published var connectionState: ConnectionState = .disconnected

    var cancellables = Set<AnyCancellable>()
    var requestingPIDs: [OBDCommand] = [.mode1(.rpm)] {
        didSet {
            addPID(command: requestingPIDs[-1])
        }
    }
    
    init() {
        obdService.$connectionState
            .assign(to: &$connectionState)
    }

    let obdService = OBDService(connectionType: .bluetooth)

    func startContinousUpdates() {
        obdService.startContinuousUpdates([.mode1(.rpm)]) // You can add more PIDs
            .sink { completion in
                print(completion)
            } receiveValue: { measurements in
                self.measurements = measurements
            }
            .store(in: &cancellables)
    }

    func addPID(command: OBDCommand) {
        obdService.addPID(command)
    }

    func stopContinuousUpdates() {
        cancellables.removeAll()
    }

    func startConnection() async throws  {
        let obd2info = try await obdService.startConnection(preferedProtocol: .protocol6)
        print(obd2info)
    }

    func stopConnection() {
        obdService.stopConnection()
    }

    func switchConnectionType() {
        obdService.switchConnectionType(.wifi)
    }

    func getStatus() async {
        let status = try? await obdService.getStatus()
        print(status ?? "nil")
    }

    func getTroubleCodes() async {
        let troubleCodes = try? await obdService.scanForTroubleCodes()
        print(troubleCodes ?? "nil")
    }
}

struct ContentView: View {
    @ObservedObject var viewModel = ViewModel()
    var body: some View {
        VStack(spacing: 20) {
            Text("Connection State: \(viewModel.connectionState.rawValue)")
            ForEach(viewModel.requestingPIDs, id: \.self) { pid in
                Text("\(pid.properties.description): \(viewModel.measurements[pid]?.value ?? 0) \(viewModel.measurements[pid]?.unit.symbol ?? "")")
            }
            Button("Connect") {
                Task {
                    do {
                        try await viewModel.startConnection()
                        viewModel.startContinousUpdates()
                    } catch {
                        print(error)
                    }
                }
            }
            .buttonStyle(.bordered)

            Button("Stop") {
                viewModel.stopContinuousUpdates()
            }
            .buttonStyle(.bordered)

            Button("Add PID") {
                viewModel.requestingPIDs.append(.mode1(.speed))
            }
        }
        .padding()
    }
}

Supported OBD2 Commands

A comprehensive list of supported OBD2 commands will be available in the full documentation (coming soon).

Important Considerations

• Ensure you have a compatible ELM327 OBD2 adapter.
• Permissions: If using Bluetooth, your app may need to request Bluetooth permissions from the user.
• Error Handling: Implement robust error handling mechanisms to gracefully handle potential communication issues.
• Background Updates (Optional): If your app needs background OBD2 data updates, explore iOS background fetch capabilities and fine-tune your library and app to work effectively in the background.

Contributing

This project welcomes your contributions! Feel free to open issues for bug reports or feature requests. To contribute code:

1. Fork the repository.
2. Create your feature branch.
3. Commit your changes with descriptive messages.
4. Submit a pull request for review.

License

The Swift OBD package is distributed under the MIT license. See the LICENSE file for more details.

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