RTC rtc(dst_on); U8GLIB_SH1106_128X64 u8g(u8g_i2c_opt_none U8G_I2C_OPT_DEV_0);

Transcription

1 #include <RTC.h> #include <Wire.h> #include <U8glib.h> #include <string.h> RTC rtc(dst_on); U8GLIB_SH1106_128X64 u8g(u8g_i2c_opt_none U8G_I2C_OPT_DEV_0); const int WIDTH=128; const int HEIGHT=35; const int LENGTH=WIDTH; //width of OLED screen is 128 pixels. //set height of graph //size of the y array const int analoginpin = A0; int x; int y[length]; // Volatile Variables, used in the interrupt service routine volatile int BPM; // int that holds raw Analog in 0. updated every 2mS volatile int Signal; // holds the incoming raw data volatile int IBI = 600; // int that holds the time interval between beats! Must be seeded! volatile boolean Pulse = false; // "True" when User's live heartbeat is detected. "False" when not a "live beat". volatile boolean QS = false; // becomes true when Arduoino finds a beat. volatile int rate[10]; // array to hold last ten IBI values volatile unsigned long samplecounter = 0; // used to determine pulse timing volatile unsigned long lastbeattime = 0; // used to find IBI volatile int P =512; // used to find peak in pulse wave, seeded volatile int T = 512; // used to find trough in pulse wave, seeded volatile int thresh = 525; // used to find instant moment of heart beat, seeded volatile int amp = 100; // used to hold amplitude of pulse waveform, seeded volatile boolean firstbeat = true; // used to seed rate array so we startup with reasonable BPM volatile boolean secondbeat = false; // used to seed rate array so we startup with reasonable BPM void cleary(){ // Clears graph. Starts with first element, check if i is less than the length of the array, increment i for(int i=0; i<length; i++){ y[i] = -1; // Make the y array empty

2 void draw() { u8g.setfont(u8g_font_unifont); // Prints BPM and IBI on screen with designated font. char bpmstr[3]; // Declares a char* of size 3 char bpmoutput[81]; // Declares a char* of size 81 (this can probably be smaller and still work fine) strcpy(bpmoutput, "BPM:"); // Copies "BPM:" into the bpmoutput char* sprintf(bpmstr,"%d", BPM); // Converts the integer BPM into a string and store it in bpmstr (size 3) strcat(bpmoutput, bpmstr); // Puts bpmstr at the end of bpmoutput (results in a string of "BPM:" followed by bpmstr. This stores the combined char* inside output. Output must be long enough (81 is much more than long enough). u8g.drawstr( 0, 64, bpmoutput); // Draws final output string char ibistr[3]; char ibioutput[81]; strcpy(ibioutput, "IBI:"); sprintf(ibistr, "%d", IBI); strcat(ibioutput, ibistr); u8g.drawstr(62, 64, ibioutput); // Same procedure to concatenate IBI value to "IBI:" void drawy(){ u8g.drawpixel(0, y[0]); for(int x=1; x<length; x++){ if(y[x]!=-1){ // if the y array is not empty u8g.drawline(x-1, y[x-1], x, y[x]); // Draws line from point (i-1, y[i-1]) to point (i,y[i]). (0, y[0], 1, y[1]) -> (1, y[1], 2, y[2])... else{ // if a value does not exist in the y array, drawy() function stops break; void drawtime(){ Data d = rtc.getdata(); char Y[20]; sprintf(y, "%d", d.year); strcat(y, "/"); char m[5]; sprintf(m, "%d", d.month); strcat(m, "/"); // function to display date and time on OLED screen // acquire data from RTC library // year array // add value of year to the year array // attach "/" at the end // month array // add value of month to the month array

3 char day[5]; sprintf(day, "%d", d.day); strcat(y, m); strcat(y, day); char h[20]; sprintf(h, "%d", d.hour24h); strcat(h, ":"); // day array // add value of day to day array // add month to the end of year array // add day to the end of year array // hour array // add value of hour to hour array // add colon at the end of hour char minute[5]; // minute array sprintf(minute, "%d", d.minutes); // add value of minutes to minute array strcat(minute, ":"); // add colon at the end of minute char s[5]; sprintf(s, "%d", d.seconds); strcat(h, minute); strcat(h, s); // second array // add value of seconds to second array // concatenate minute to hour // concatenate seconds to hour u8g.setfont(u8g_font_6x13); u8g.drawstr(0, 10, Y); u8g.drawstr(78, 10, h); // set font // draw date on OLED // draw hour on OLED void interruptsetup(){ // Initializes Timer2 to throw an interrupt every 2mS. TCCR2A = 0x02; // DISABLE PWM ON DIGITAL PINS 3 AND 11, AND GO INTO CTC MODE TCCR2B = 0x06; // DON'T FORCE COMPARE, 256 PRESCALER OCR2A = 0X7C; // SET THE TOP OF THE COUNT TO 124 FOR 500Hz SAMPLE RATE TIMSK2 = 0x02; // ENABLE INTERRUPT ON MATCH BETWEEN TIMER2 AND OCR2A sei(); // MAKE SURE GLOBAL INTERRUPTS ARE ENABLED // THIS IS THE TIMER 2 INTERRUPT SERVICE ROUTINE. // Timer 2 makes sure that we take a reading every 2 miliseconds ISR(TIMER2_COMPA_vect){ // triggered when Timer2 counts to 124 cli(); // disable interrupts while we do this, otherwise function might interrupt itself. Signal = analogread(analoginpin); // read the Pulse Sensor samplecounter += 2; // keep track of the time in milliseconds with this

4 variable int N = samplecounter - lastbeattime; avoid noise // monitor the time since the last beat to // find the peak and trough of the pulse wave if(signal < thresh && N > (IBI/5)*3){ // avoid dicrotic noise by waiting 3/5 of last IBI if (Signal < T){ // T is the trough T = Signal; // keep track of lowest point in pulse wave if(signal > thresh && Signal > P){ // thresh condition helps avoid noise P = Signal; // P is the peak // keep track of highest point in pulse wave // LOOK FOR THE HEART BEAT // signal surges up in value every time there is a pulse if (N > 250){ // avoid high frequency noise if ( (Signal > thresh) && (Pulse == false) && (N > (IBI/5)*3) ){ Pulse = true; // set the Pulse flag when we think there is a pulse IBI = samplecounter - lastbeattime; // measure time between beats in ms lastbeattime = samplecounter; // keep track of time for next pulse if(secondbeat){ secondbeat = false; for(int i=0; i<=9; i++){ startup rate[i] = IBI; // if this is the second beat, if secondbeat == TRUE // clear secondbeat flag // seed the running total to get a realisitic BPM at if(firstbeat){ // if it's the first time we found a beat, if firstbeat == TRUE firstbeat = false; // clear firstbeat flag secondbeat = true; // set the second beat flag sei(); // enable interrupts again return; // IBI value is unreliable so discard it, because there is no previous beat before the first beat to calculate the IBI. // keep a running total of the last 10 IBI values word runningtotal = 0; // clear the runningtotal variable for(int i=0; i<=8; i++){ rate[i] = rate[i+1]; runningtotal += rate[i]; // shift data in the rate array // and drop the oldest IBI value // add up the 9 oldest IBI values

5 rate[9] = IBI; // add the latest IBI to the rate array runningtotal += rate[9]; // add the latest IBI to runningtotal runningtotal /= 10; // average the last 10 IBI values and store value in runningtotal BPM = 60000/runningTotal; // how many beats can fit into a minute? that's BPM! QS = true; // set Quantified Self flag // QS FLAG IS NOT CLEARED INSIDE THIS ISR if (Signal < thresh && Pulse == true){ // when the values are going down, the beat is over Pulse = false; // reset the Pulse flag so we can do it again amp = P - T; // get amplitude of the pulse wave thresh = amp/2 + T; // set thresh at 50% of the amplitude P = thresh; // reset these for next time T = thresh; if (N > 2500){ // if 2.5 seconds go by without a beat thresh = 512; // set thresh default P = 512; // set P default T = 512; // set T default lastbeattime = samplecounter; // bring the lastbeattime up to date firstbeat = true; // set these to avoid noise secondbeat = false; // when we get the heartbeat back BPM = 0; // BPM is 0 when there is no heartbeat detected IBI = 0; // IBI is 0 when there is no heartbeat detected sei(); // enable interrupts at the end // end isr void setup() { x = 0; // initialize x at 0 so that the graph starts on the left side of OLED for(int x = 0; x < LENGTH; x++){ // initialize y array so that every y is initially mapped at 35 the first time through y[x] = 35; interruptsetup(); // set up timer2 // IMPORTANT! // It allows to set the time and date of the clock.

6 // Once configured, delete (or comment) the code and rewrite the code in the Arduino. // Otherwise whenever you turn on the Arduino will modify the time. // SET DATE // //rtc.setyear(2015); //rtc.setmonth(07); //rtc.setday(28); //rtc.setdate( 2015, 07, 28 ); // Year, Month and Day // SET TIME // //rtc.sethour(15); //rtc.setminutes(03); //rtc.setseconds(00); //rtc.settime(15, 03, 00 ); // Hour24H, Minutes and Seconds ///////// // SET DATE AND TIME // ///////// //rtc.setdatetime( 2015, 07, 28, 15, 03, 00 ); // Year, Month, Day, Hour24H, Minutes and Seconds void loop() { if (QS = true) { y[x] = map(signal, 0, 1023, HEIGHT, 15); Height, 1023 is mapped at 0. // Maps Signal on screen. 0 is mapped at u8g.firstpage(); do { drawy(); drawtime(); // u8glib picture loop procedure starts.

7 draw(); while( u8g.nextpage() ); x++; if(x >= WIDTH){ x = 0; // Reset x back to 0 cleary(); // clear graph QS = false; //end of picture loop. // Increments x // when x value exceeds width of display