Dangerous Prototypes Open Source Hardware

• 72 7-segment displays in three rings; inner (hour) ring 12 displays, middle (minute) ring 24 and outer (seconds) ring 36 displays
• Light sensor for adaptive display intensity; lighter during the day, dimmed at night
• Movement sensor for waving interaction; show time/date with a wave of your hand
• Each segment individually addressable with 256 levels of intensity
• Ethernet connectivity for remote control and power entry
• NTP synchronization for (near) perfect time
• Some blinkenleds for indicative purposes
• Buttons and RTC for off-line time-keeping
• 3D printed case in four sections with Plexiglas cover and back

SAVEZ = 5.0;
HOME = [0, 0, SAFEZ];
feedrate(100.0);       // Set the feedrate (F) to 100mm/min
goto([100mil, 100mm]); // go to (G0) location x=100.0*0.254mm, y=100mm
move([-,-,-10]);       // move to (G1) location Z=-10mm
move([-,-,SAFEZ]);     // move to (G1) location Z=5mm
goto(HOME);            // go to (G0) home position

#include <stdint.h>
/*
 * Divide by 10 with remainder.
 *
 * Use the recurring reciprocal 8/10 = 0.1100 1100 1100...
 * See: http://www.hackersdelight.org/divcMore.pdf 
 *
 * This routine runs in constant time in about 128 clock-cycles (or 16us @
 * Fosc/4=8MHz). Normal division/modulo would take many thousand cycles.
 */
uint16_t dm10val;	/* Input/output div 10 */
uint8_t dm10rem;	/* Remainder of div 10 */

#ifdef HAVE_MUL
void divmod10(void)
{
	uint16_t q = (dm10val >> 1) + (dm10val >> 2);	/* First approx. */
	q += q >> 4;			/* Second approx. */
	q += q >> 8;			/* Third approx. */
	q >>= 3;			/* div 8 to get 1/10 */
	dm10rem = dm10val - 10*q;
	q += (dm10rem + 6) >> 4;	/* rounding compensation */
	dm10rem = dm10val - 10*q;	/* Actual remainder */
	dm10val = q;			/* Result */
}
#else
void divmod10(void)
{
	uint16_t q = (dm10val >> 1) + (dm10val >> 2);	/* First approx. */
	q += q >> 4;			/* Second approx. */
	q += q >> 8;			/* Third approx. */
	q >>= 3;			/* div 8 to get 1/10 */
	dm10rem = dm10val - ((q + (q << 2)) << 1);	/* rem = val - 10*q */
	q += (dm10rem + 6) >> 4;	/* rounding compensation */
	dm10rem = dm10val - ((q + (q << 2)) << 1);	/* Actual remainder */
	dm10val = q;			/* Result */
}
#endif

void func(void)
{
	dm10val = 1234;
	divmod10();
	do_something_with_result(dm10val);
	do_something_with_remainder(dm10rem);
}