Connecting the Mcwhlr Magic Panel
Connecting the mcwhlr "Magic Panel"
The so-called magic panel is a picture framed panel on R2's dome that normally appears silver, but lights up bright red in a scene of Episode III when R2 is catpured by the Jawas. Michael Wheeler (who goes by user "mcwhlr") makes a very nice version of this panel, available on the Astromech.com forum, which can replace a more prosaic red LED or my own HoloLight driver fitted with a red light.
Version 1.3 and later of the MarcDuino Slave firmware is compatible with Michael Wheeler's Magic Panel. The panel connects to the slave MarcDuino board (2nd board, HP Controller) in place of a simple LED or my HoloLight driver.
However, the magic panels have been shipped with two different versions of the software, and you need to connect them slightly differently.
The magic panel should respond to the on, off and flicker R2 Touch commands. The panel should also trigger automatically in the scream and faint (short circuit) sequences issued by R2 Touch. Other Magic Panel modes are not supported at present.
Magic Panels from the first run
Besides the power supply, connect the blue and black wires as shown between the Magic Panel and the header marked SRV10 on the HP MarcDuino. The black wires connect the ground together (and is optional if the two boards are powered by the same ground), while the blue wire connects to the signal pin of the SRV10 header.
Here is a detailed view of the wire locations on the Magic Panel. They are on the row closest to the edge of the board. If the boards share a common power ground, the only connection you need is the blue wire, you can omit the black one.
Detail of the wire locations on the MarcDuino (this is from an early prototype board, but location is the same on the newer boards)
Magic Panels from later runs
The pins have moved around. I haven't tested this, but users of new panels report this wiring works:
The S pin goes to the pin marked 3 on the magic panel, and the - pin goes to the magic panel pin marked 4.