{"id":15,"date":"2014-10-30T13:13:00","date_gmt":"2014-10-30T13:13:00","guid":{"rendered":""},"modified":"2021-05-23T16:47:13","modified_gmt":"2021-05-23T15:47:13","slug":"binary-clock-4","status":"publish","type":"post","link":"https:\/\/blog.hslracing.com\/electronics\/2014\/10\/binary-clock-4.html","title":{"rendered":"Binary Clock 4"},"content":{"rendered":"

I recently re-read an article, I had originally read some time ago, about an arduino clock source using a single wire, on Instructables<\/a> by relic1974, and thought that this might possibly be a more accurate clock signal than the tone value I am currently using.<\/p>\n

The internal timer is not overly accurate and there seems to be enough fluctuation in the tone output to cause my clock to gain or lose seconds over a relatively short period of time.<\/p>\n

There are no required changes to my board layout as since as with most of the pins on an ATtiny44<\/a>, D3 is also an analog pin (A7), in addition to which it is also one of 4 PWM capable pins.<\/p>\n

Using a PWM signal makes for slightly smaller hex code as I would no longer require the tone()<\/a> function, as it would be replaced with an analogWrite()<\/a> function instead.<\/p>\n

The binary sketch size is 3072 bytes for  the tone()<\/a> version and 2264 bytes for the PWM version,<\/p>\n

I was not exactly strapped for space on my ATtiny44<\/a> chip, but now it will even fit on an ATtiny24<\/a> chip.<\/p>\n

I have also decided to make use of bounce2<\/a>, newer more enhanced debounce code, which requires a couple more changes.<\/p>\n

The full version of the new code is posted below:

<\/span>#include <Bounce2.h><\/span>

<\/span>#define TONEPIN 7           \/\/ Analog pin 7 (pa7) used as PWM output<\/span>
#define BUTTON1 1           \/\/ digital pin 0 (pb1) used to set clock<\/span>
#define BUTTON2 4           \/\/ digital pin 6 (pa6) used to set clock<\/span>

<\/span>int masterClock = 0;<\/span>
int lastsec = 0;<\/span>
int seconds = 0;<\/span>
int minutes = 0;<\/span>
int hours = 0;<\/span>
int hms = 0;<\/span>
int sw1 = 0;<\/span>
int sw2 = 0;<\/span>
int both = 0;<\/span>
boolean sw1on = false;<\/span>
boolean sw2on = false;<\/span>
boolean bothon = false;<\/span>

<\/span>const int nPins = 5;<\/span>
const int pins[] = {6, 7, 8, 9, 10};<\/span>
const int clock[17][2] = { {6, 7}, {6, 8}, {7, 8}, {8, 9}, {8, 10}, {9, 10},    \/\/ Seconds LEDs<\/span>
                           {7, 6}, {8, 6}, {8, 7}, {9, 8}, {10, 8}, {10, 9},    \/\/ Minutes LEDs<\/span>
                           {9, 6}, {6, 9}, {6, 10}, {10, 7}, {7, 10} };         \/\/ Hours LEDs<\/span>

<\/span>Bounce button1 = Bounce();<\/span>
Bounce button2 = Bounce();<\/span>

<\/span>void setup() {<\/span>
  attachInterrupt(0, tick, CHANGE); \/\/ call ISR on change to INT0 (digital pin 2)<\/span>
  analogReference(DEFAULT);  \/\/ default 5V reference<\/span>
  analogWrite(TONEPIN, 127); \/\/ start PWM with 50% duty cycle as clock input for ISR<\/span>
  pinMode(BUTTON1, INPUT);   \/\/ setup button1 for input<\/span>
  pinMode(BUTTON2, INPUT);   \/\/ setup button2 for input<\/span>
  button1.attach(BUTTON1);<\/span>
  button1.interval(5);       \/\/ set 5ms debounce interval for BUTTON1<\/span>
  button2.attach(BUTTON2);<\/span>
  button2.interval(5);       \/\/ set 5ms debounce interval for BUTTON2<\/span>
}<\/span>

<\/span>void tick() {                \/\/ Interrupt Service Routine to generate 1 second “tick”<\/span>
  masterClock++;             \/\/ increment clock counter<\/span>
  if (masterClock >= 979) {  \/\/ 980 ticks reached (490Hz * 2)<\/span>
    seconds++;               \/\/ increment seconds<\/span>
    masterClock = 0;         \/\/ reset masterClock<\/span>
  }<\/span>
}<\/span>

<\/span>void turnon(int led) {<\/span>
  int Vcc = clock[led][0];<\/span>
  int Gnd = clock[led][1];<\/span>
  pinMode(Vcc, OUTPUT);<\/span>
  pinMode(Gnd, OUTPUT);<\/span>
  digitalWrite(Vcc, HIGH);<\/span>
  digitalWrite(Gnd, LOW);<\/span>
}<\/span>

<\/span>void alloff() {<\/span>
  for (int i = 0; i < nPins; i++) {<\/span>
    digitalWrite(pins[i], LOW);<\/span>
    pinMode(pins[i], INPUT);<\/span>
  }<\/span>
}<\/span>

<\/span>void showtime(int Value, int Width, int Offset) {<\/span>
  int mask;<\/span>
    for (int i = 0; i < Width; i++) {<\/span>
      mask = 1 << i;          \/\/ shift bit mask by current position<\/span>
      if (HIGH && (Value & mask)) {      \/\/ check if LED should be lit<\/span>
        turnon(Offset + i);   \/\/ turn on the LED<\/span>
        alloff();<\/span>
      }<\/span>
  }<\/span>
}<\/span>

<\/span>void loop() {<\/span>
  \/\/ Check if buttons have been pressed  <\/span>
  button1.update();                \/\/ update button1<\/span>
  button2.update();                \/\/ update button2<\/span>
  sw1 = button1.read();            \/\/ button 1 state<\/span>
  sw2 = button2.read();            \/\/ button 2 state<\/span>
  both = sw1 && sw2;               \/\/ both state<\/span>

<\/span>  if (sw1 == 0) sw1on = false;<\/span>
  if (sw2 == 0) sw2on = false;<\/span>
  if (both == 0) bothon = false;<\/span>

<\/span>  \/\/ toggle setup states if both buttons are pressed and then released together<\/span>
  if (both && !bothon) {<\/span>
    if (hms == 0) hms=1;       \/\/ toggle hours\/minutes\/seconds to hours if entering setup mode<\/span>
    else hms = 0;              \/\/ toggle hours\/minutes\/seconds to off if leaving setup mode<\/span>
    bothon = true;             \/\/ set flag for both buttons on<\/span>
  }<\/span>

<\/span>  \/\/ set hours(1), minutes(2), or seconds(3)<\/span>
  if ((hms != 0) && sw1 && !sw1on && !bothon) {<\/span>
    hms++;                            \/\/ toggle hours\/minutes\/seconds<\/span>
    if (hms == 4) hms = 1;            \/\/ reset back to hours if hms goes beyond seconds<\/span>
  sw1on = true;<\/span>
  }<\/span>
  <\/span>
  if ((hms != 0) && sw2 && !sw2on && !bothon) {<\/span>
    if (hms == 1) {<\/span>
      hours++;<\/span>
      if (hours == 24) hours = 0;<\/span>
    }<\/span>
    if (hms == 2) {<\/span>
      minutes++;<\/span>
      if (minutes == 60) minutes = 0;<\/span>
    }<\/span>
    if (hms == 3) {<\/span>
      seconds = 0;<\/span>
    }<\/span>
    sw2on = true;<\/span>
  }<\/span>
    <\/span>
  \/\/ Adjust the time based on seconds passed<\/span>
  if (seconds == 60) {<\/span>
    minutes++;                \/\/ increment minutes when seconds reach 60<\/span>
    if (minutes == 60) {<\/span>
      hours++;                \/\/ increment hours when minutes reach 60<\/span>
      if (hours == 24) {<\/span>
        hours = 0;            \/\/ reset hours when hours reaches 24<\/span>
      }<\/span>
      minutes = 0;            \/\/ reset minutes when minutes reaches 60<\/span>
    }<\/span>
    seconds = 0;              \/\/ reset seconds when seconds reaches 60<\/span>
  }<\/span>
  <\/span>
  showtime(seconds, 6, 0);   \/\/ Display seconds (LEDs 0-5)<\/span>
  showtime(minutes, 6, 6);   \/\/ Display minutes (LEDs 6-11)<\/span>
  showtime(hours, 5, 12);    \/\/ Display hours (LEDs 12-16)<\/span>
}<\/span><\/div>\n","protected":false},"excerpt":{"rendered":"

I recently re-read an article, I had originally read some time ago, about an arduino clock source using a single wire, on Instructables by relic1974, and thought that this might possibly be a more accurate clock signal than the tone value I am currently using. The internal timer is not overly accurate and there seems to…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-15","post","type-post","status-publish","format-standard","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts\/15","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/comments?post=15"}],"version-history":[{"count":1,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts\/15\/revisions"}],"predecessor-version":[{"id":83,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/posts\/15\/revisions\/83"}],"wp:attachment":[{"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/media?parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/categories?post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.hslracing.com\/electronics\/wp-json\/wp\/v2\/tags?post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}