91d6b5af4b
The code should be able to handle 3 electrodes for R, G and B. Didn't test it so far (need 2 other electrodes).
101 lines
2.5 KiB
C++
101 lines
2.5 KiB
C++
/* Touchless tracking
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* ==================
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* This code takes as many measurements as it can at approximately
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* 10Hz = 60 Hz / (2 full cycles * 3 sensors).
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*
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* The code takes as many measurements as possible on the period of two
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* cycles of the main power frequency, in order to cancel out any potential
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* coupling.
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*
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* Original code was found on instructables :
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* http://www.instructables.com/id/DIY-3D-Controller/
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*
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* Code slightly modified and commented by Phyks for HackENS
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*
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* As I found the code on Instructables and I don't give a damn to the
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* modifications I made, you may reuse it freely by writing where you
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* found it.
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*/
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#define resolution 8
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// Frequency of main power to avoid coupling
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#define mains 50
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// Time between measures
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#define refresh 2 * 1000000 / mains
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// Pins to use
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// Must be between 8 and 13 to use this code without
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// modifications (PORTB is for pins 8 to 13)
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//
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// Note : If you change pin numbers, you *must* change the mask.
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// See arduino doc for more info.
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#define PIN_R 8
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#define MASK_R B00000001
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#define PIN_G 9
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#define MASK_G B00000010
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#define PIN_B 10
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#define MASK_B B00000100
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// Counter for the timer
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extern volatile unsigned long timer0_overflow_count;
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void startTimer() {
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timer0_overflow_count = 0;
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TCNT0 = 0; // Initialize counter value to 0
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}
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unsigned long checkTimer() {
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return ((timer0_overflow_count << 8) + TCNT0) << 2;
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}
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long time(int pin, byte mask) {
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unsigned long count = 0, total = 0;
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while(checkTimer() < refresh) {
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// Note : pinMode is about 6 times slower than assigning
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// DDRB directly, but that pause is important
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// Set pin as output and LOW, see arduino doc for info on PORTB
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pinMode(pin, OUTPUT);
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PORTB = 0;
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// Set it as INPUT to take measure
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pinMode(pin, INPUT);
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// While PINB is low, increment counter
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while((PINB & mask) == 0)
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count++;
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total++;
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}
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// Restart timer for next measurement
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startTimer();
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// Return the measurement result
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return (count << resolution) / total;
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}
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void setup() {
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// Initialize serial communication
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Serial.begin(115200);
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// INPUT on pins
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pinMode(PIN_R, INPUT);
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pinMode(PIN_G, INPUT);
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pinMode(PIN_B, INPUT);
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// Start timer
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startTimer();
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}
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void loop() {
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// Print output to serial in decimal
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Serial.print(time(PIN_R, MASK_R), DEC);
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Serial.print(" ");
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Serial.print(time(PIN_G, MASK_G), DEC);
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Serial.print(" ");
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Serial.print(time(PIN_B, MASK_B), DEC);
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Serial.print("\n");
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}
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