Here are a few notes on maintenance of an Energica EsseEsse9

Heated grips replacement: Oxford Products OF690

When I'm in Microsoft Excel on macOS, I often want to clean up and delete rows. The online documentation is weird, and mentions a non-working shortcut key. To delete a row with the keyboard, navigate to the row, then press Shift-Space, then Control-Minus. This works on macOS Sonoma 14.5 with Microsoft Excel 16.81.

TL;DR: Raspberry Pi OS will reject rsa keys, use another type of key, and copy it to the Pi:

  % ssh-keygen -t ecdsa
  % ssh-copy-id .ssh/id_ecdsa.pub <pi-hostname>

Explanation is as follows. Recently I installed a Raspberry Pi 4, and I flashed the SD card with the Raspberry Pi Imager. I used the default OS (which is titled "Raspberry Pi OS, a port of Debian Bookworm"). I wanted to use passwordless login to ssh, i.e. public key authentication. So I copied my existing public key to the Raspberry Pi with ssh-copy-id. However when accessing the Pi over ssh, I still had to enter my password.

This had me stumped for a while. In the end, I turned on debug logging:

  % sudo vim /etc/ssh/sshd_config

Then add the following line:

  LogLevel DEBUG3

Restart SSH daemon and follow logs:

  % sudo systemctl restart sshd
  % journalctl -f

Try and log in with your old RSA key, and you'll see the following log message:

  Dec 01 09:27:53 HL46528028 sshd[2025]: debug3: mm_answer_keyallowed: publickey authentication test: RSA key is not allowed

What you need to do, is generate a new key with a different type:

  % ssh-keygen -t ecdsa

The default is to save they keypair in the ~/.ssh directory and call it id_ecdsa and id_ecdsa.pub. Copy the public key to the Raspberry:

  % ssh-copy-id .ssh/id_ecdsa.pub <pi-hostname>

Now enjoy passwordless login:

  % ssh <pi-hostname>

Of course don't forget to remove the LogLevel line from the sshd configuration, and restart the daemon.

In SwiftUI, it's easy to just keep coding and dump everything in one view. Toolbars especially are "bulky", they take up a lot of lines, and are not regular views so syntax-wise, they're a bit of a bother to separate away. Here's an example of a bottom toolbar, to help you split up those big views.

    struct MainView: View {
        var body: some View {
            Color.blue
                .ignoresSafeArea(edges: [.top, .leading, .trailing])
                .toolbar {
                    ActionToolbar()
                }
        }
    }

    struct ActionToolbar: ToolbarContent {
        var body: some ToolbarContent {
            ToolbarItem(placement: .bottomBar) {
                 Spacer()
             }
            ToolbarItem(placement: .bottomBar) {
                Button(action: { print("Plus") }) {
                    Image(systemName: "plus.app.fill")
                        .resizable()
                        .scaledToFit()
                }
            }
        }
    }

When you're using the Coordinator pattern in a SwiftUI project, you'll find yourself sometimes wanting to preview the initial start of a "flow" of screens. But that's quite a bit of work because inside the coordinator, some boilerplate code needs to be present, to wrap the SwiftUI view in a UIHostingController.

This bit of code is useful to plunk in the utilities folder of your project, and use in the preview section of your SwiftUI view.

    private class PreviewViewController: UIViewController {
        private let coordinator: NavigationControllerCoordinator

        init(coordinator: NavigationControllerCoordinator) {
            self.coordinator = coordinator
            super.init(nibName: nil, bundle: nil)
        }

        required init?(coder: NSCoder) {
            fatalError()
        }

        override func viewDidLoad() {
            guard let navigationController = self.navigationController as? NavigationController else {
                return
            }
            title = "Preview"

            var configuration = UIButton.Configuration.filled()
            configuration.title = "Start"
            self.view = UIButton(configuration: configuration, primaryAction: UIAction(handler: {_ in
                navigationController.present(self.coordinator.navigationController, animated: true)
                self.coordinator.start()
            }))
        }
    }

    struct PreviewCoordinator: UIViewControllerRepresentable {
        let coordinator: NavigationControllerCoordinator

        typealias UIViewControllerType = NavigationController

        func makeUIViewController(context: Context) -> NavigationController {
            let viewController = PreviewViewController(coordinator: coordinator)
            return NavigationController(rootViewController: viewController)
        }

        func updateUIViewController(_ uiViewController: NavigationController, context: Context) {}
    }

Use as follows;

    struct NetworkScanQRView_Previews: PreviewProvider {
        static var previews: some View {
            PreviewCoordinator(coordinator: NetworkScanQRCoordinator.mocked)
        }
    }