Remote buzzer: Add rotary switch support and button for print

[jacques42]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "x" next to an item)

• Documentation update
• New feature

Fix #182

What changes did you make? (Give an overview)

Hardware Button (Remote Buzzer):

1) Added Rotary Switch support and mode for navigating the Photobooth screen.

In rotary mode a rotary encoder (i.e. KY-040) is connected to the GPIOs. Turning the rotary left / right will navigate through the currently visible set of buttons on the screen. Button press on the rotary will activate the currently highlighted button in Photobooth

The wiring layout is

Button                          Rotary Encoder
Mode           Raspberry        Mode

Picture  ---   GPIO 21    ---   DT
Collage  ---   GPIO 20    ---   CLK
Shutdown ---   GPIO 16    ---   SW
                3V3       ---   +
                GND       ---   GND

Known limitations:
The following elements are currently not supported and not accessible through the rotary navigation

• Delete Picture
• Full Screen Mode button
• Download button

2) Added hardware button support for PRINT

If operating in Button Mode, now GPIO26 will support to trigger print-out via a hardware button. Printing can be triggered from the results screen or from the Gallery - Photoswipe screen.

Note that for the button to work, printing from results screen and from gallery needs to be enabled in the ' Admin Panel -> Print' section

Is there anything you'd like reviewers to focus on?

Please test the functionality also with a screen locally connected to the Raspberry Pi

[andi34]

Edit: obsolet