Arduino LED bar with rhythm detection
Yesterday I posted a Rhythm Detection prototype which included a new library for measuring time intervals between events.
That prototype was a stepping stone to this more complex circuit which times the LED animation to the beat input by the user.
Similar to the previous circuit, the user pushes a button to the beat. The code records the tap intervals and calculates the BPM, flashing an LED to the beat. The beat timing controls the animation of a 8x LED matrix managed through a basic Shift Register.
I've separated out the patterns into a separate file, and although it took a bit of trial and error, I finally got the timing right.
If you're planing on building circuit, be sure to remember that your animation sequences need to be structured like the music you're working with - so group sequences into four beats, etc. (took me a while to get that right)
The code uses two libraries:
And details on the circuit can be found here.
If you're looking for the timing circuit only, the blog post is here.
10x LEDs (2x red, 8x yellow, or any other colour combination)
1x breadboard mountable button
10x 330Ω resistors (or which ever resistors best suit your LEDs)
1x 74HC595 Shift Register
Note: almost all the projects I put together use the SparkFun Arduino UNO Inventors Kit and SparkFun Beginner Parts Kit which you can buy at ToysDownUnder.com.
Note: you can download the Fritzing file here.
#include <tap.h> - http://github.com/d2kagw/arduino-tap-library/ #include <rhythm.h> - http://github.com/d2kagw/arduino-rhythm-library/ // the animation patterns are saved in the patterns.h file // in an attempt to keep this file clean #include "patterns.h" // ---------------------------------- // Configuration Vars // // all the pin declerations - change if necessary #define PIN_BUTTON 10 #define PIN_LED_BEAT 9 #define PIN_LED_STATUS 8 #define PIN_SERIAL_DATA 2 #define PIN_SERIAL_LATCH 3 #define PIN_SERIAL_CLOCK 4 // By default the app will require ten 'taps' // but you can change this value to a smaller number if you like // the larger the number, the greater the accuracy, but the longer // the learning process int requiredTaps = 6; // ---------------------------------- // Internal Vars // // pattern cycle management int pattern_index = 0; int pattern_count = (sizeof(patterns) - 1) / 2; // Tap and Rhythm library Tap tapper(PIN_BUTTON); Rhythm beater; // learning state management boolean _isListening = false; boolean _isFirst = false; int _tapCount = 0; // animation management unsigned int _clock = 0; unsigned int _timingClock = 0; unsigned int _requiredTiming = 0; // ---------------------------------- // Setup // void setup () { // Start the logger Serial.begin(9600); // setup the LED pins pinMode( PIN_LED_STATUS, OUTPUT); pinMode( PIN_LED_BEAT, OUTPUT); pinMode( PIN_SERIAL_DATA, OUTPUT); pinMode( PIN_SERIAL_CLOCK, OUTPUT); pinMode( PIN_SERIAL_LATCH, OUTPUT); // reset the animation & shift register resetAnimation(); }; // ---------------------------------- // Main Loop // void loop() { // control the animation timing based on the stored beat // if we're not listening and we've got a beat timing... if (!_isListening && beater.currentTiming != 0) { // look for whole beats // just for the beat status light if (_clock == beater.currentTiming) { Serial.println("doof"); digitalWrite(PIN_LED_BEAT, digitalRead(PIN_LED_BEAT) != HIGH); _clock = 0; } // if the clock is at the required timing if (_timingClock == _requiredTiming) { // move to the next stage of the LED Matrix animation digitalWrite(PIN_SERIAL_LATCH, LOW); shiftOut(PIN_SERIAL_DATA, PIN_SERIAL_CLOCK, MSBFIRST, patterns[pattern_index*2]); digitalWrite(PIN_SERIAL_LATCH, HIGH); // store the timing for the next cycle _requiredTiming = ((beater.currentTiming * patterns[(pattern_index*2)+1]) / WHOLE_BEAT); // increment the pattern index pattern_index ++; // loop if necessary if (pattern_index > pattern_count) pattern_index = 0; // reset the clock _timingClock = 0; } // increment the clock _timingClock ++; _clock ++; } else { digitalWrite(PIN_LED_BEAT, LOW); } // call the beat manage method // this guy controls the detection of ze rhythm beatManage(); // a delay is required for the timing to work correctly. // not entirely sure why this is the case, // maybe someone smarter than I could explain? delay(1); } // -------------------------------------------------------------- // Reset Animation, called when the user is changing the timing // void resetAnimation() { // reset the shift register back to null digitalWrite(PIN_SERIAL_LATCH, LOW); shiftOut(PIN_SERIAL_DATA, PIN_SERIAL_CLOCK, MSBFIRST, B00000000); digitalWrite(PIN_SERIAL_LATCH, HIGH); // all indexes back to zero pattern_index = 0; _timingClock = 0; _clock = 0; _requiredTiming = 0; } // --------------------------------------- // Where all the beat management occurs // void beatManage() { // if the button is down... if (tapper.isHit()) { // and we're not currently counting taps if (_isListening == false) { // start counting taps _isListening = _isFirst = true; _tapCount = 0; // call the reset method resetAnimation(); // turn on the status light so the user knows we're expecting input digitalWrite(PIN_LED_STATUS, HIGH); Serial.println("Listening"); // if we are already counting taps } else { // and this is the first tap if (_isFirst) { // reset the rhythm library beater.reset(); _isFirst = false; digitalWrite(PIN_LED_BEAT, HIGH); Serial.println("first tap"); // if it's not the first tap } else { // record the tap in the library beater.tap(); digitalWrite(PIN_LED_BEAT, HIGH); Serial.println("tap"); } // increment out counter _tapCount ++; } }; // have we reached our tap count? if (_tapCount > requiredTaps && _isListening) { // stop listening and turn off the status LED _isListening = false; digitalWrite(PIN_LED_STATUS, LOW); } // if we're listening, hit the loop if (_isListening) beater.loop(); };
Note: There is more than one file to this sketch. You can download the Arduino two files from here.</rhythm.h></tap.h>
