Password API

Some Waveshare frames support a password. The default password is 1234.

The PasswordApi class exposes the 0xFFFE commands used by the frame:

• query() — reports whether the frame has a password.
• unlock(password) — unlocks the frame.
• enable(password) — sets/enables the password.
• disable(current) — disables the password after checking the current one.
• change(current, next) — changes the password.

val api = PasswordApi(transceiver)
when (api.query()) {
    PasswordApi.Status.OK -> api.unlock(byteArrayOf('1'.code.toByte(), /* ... */))
    PasswordApi.Status.NO_PASSWORD -> api.enable(byteArrayOf(/* ... */))
    else -> // handle error
}