Because every hackerspace needs an Arduinolike board on their door.
Ours is an MHVboard which is based off the Metaboard (because every hackerspace needs to make their own Arduino clone). It is currently plugged in to the LTSP thin client sitting on the shelf where it is getting its power, but does not communicate to it yet.
Currently the mhvdoorduino implements a basic occupancy gauage. It has 4 Sure Electronics 32x8 LED matricies which get updated once a second. If, at the beginning of that second, the PIR senses movement a counter increases, if the PIR is not sensing movement, the counter decreases. The LED matrix lights up more proportianly with this counter. It currently takes 24hours of constant hacktivity to fill the whole matrix.
The Club-Mate bottle LED strip above the door is now connected to this board. There will eventually be animations on the LED strip base on the calculated hacktivity.
wclk B0
rclk B1
data B2
CS1 D4
CS2 D5
CS3 D6
CS4 D7 (yes this is a derp, when you are using the upload jumper the 4th
display gets garbage.)
The PIR sensor is hooked in to C0 with the internal pullup turned on. The logic level is inverted, but the short SENSOR macro handles that.
clk C4
data C5
If you want to hack on it read the do-ocracy sign!
The makefile now supports multiple c files and headers, if you add more source files add them to the (space separated) SRC macro. The project can bo compiled with 'make' and programmed with 'make program'. Note that the bootloader on this particular mhvboard still uses the jumper on D7 to go into programming mode after a reset. D7 is also used as a Chip Select on one of the LED matracies which gets well confused when the jumper is on.