# BigLED Wall Clock
An Arduino UNO based temperature compensated, GPS enabled and battery backed GINORMOUS wall clock using 7" LED Digits from SparkFun and other materials from Adafruit.
|Materials |Stock No.|#|Each |Total |
|----------------------------------------------------|---------|-|------|------|
|SparkFun 6" 7-segment LED |COM-08530|6|$14.95|$88.70|
|SparkFun Large Digit Driver |WIG-13279|6|$6.95 |$41.70|
|SparkFun RedBoard - Programmed with Arduino |DEV-12757|1| |$19.95|
|SparkFun GPS Receiver - GP-735 (56 Channel) |GPS-13670|1| |$39.95|
|Adafruit Monochrome 128x32 SPI OLED graphic display |661 |1| |$17.50|
|Adafruit Chronodot v2.1 |255 |1| |$17.50|
|SparkFun USB Mini-B Cable - 6 Foot |CAB-11301|1| |$3.95 |
|SparkFun Jumper Wire - 0.1", 6-pin, 12" |PRT-10376|2|$1.95 |$3.90 |
|SparkFun Jumper Wire - 0.1", 6-pin, 4" |PRT-10366|6|$0.95 |$5.70 |
|Adafruit 12V Power Supply 5a Power Supply |352 |1| |$24.95|
|SparkFun Arduino and Breadboard Holder |DEV-11235|1| |$3.95 |
|SparkFun Breadboard - Self-Adhesive (White) |PRT-12002|1| |$4.95 |
|SparkFun GPS Breakout |BOB-11818|1| |$3.95 |
|Sparkfun JST SH Jumper 6 Wire - 1 Foot |GPS-09123| | |$2.95 |
#include <Wire.h> // I2C driver library (for Chronodot)
#include <SPI.h> // SPI bus driver library (for OLED Display)
#include <RTClib.h>
#include <RTC_DS3231.h> // DS3231 based Chronodot TXO real time clock driver library
#include <Adafruit_GFX.h> // OLED display graphics library
#include <Adafruit_SSD1306.h> // OLED display hardware driver library
#define OLED_MOSI 9 // OLED pin assignments
#define OLED_CLK 10
#define OLED_DC 11
#define OLED_CS 12
#define OLED_RESET 13
Adafruit_SSD1306 SSD1306(OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS); // instantiate OLED display
RTC_DS3231 RTC; // instantiate Chronodot txo time base
char TimeString[20]; // define formatted time string
char TempString[20]; // define formatted temperature string
#define SQW_FREQ DS3231_SQW_FREQ_1024 // 0b00001000 1024Hz
byte segmentLatch = 5; // Blue BIG LED pin assignments
byte segmentClock = 6; // Green
byte segmentData = 7; // Yellow
// Orange uses 5V bus
// Red uses vin from 12v supply
// Black uses gnd bus
// long digit1; // set up BIG LED digits - must use long - 16bit tops out at 32000!
// long digit2;
// long digit3;
// long digit4;
// long digit5;
// long digit6;
long digit1, digit2, digit3, digit4, digit5, digit6; // set up BIG LED digits - must use long - 16bit tops out at 32000!
long hhmmss;
void setup() {
Serial.begin(57600); // serial monitor for debug messages
Wire.begin(); // fire up I2C bus
RTC.begin(); // fire up Chronodot
if (! RTC.isrunning()) {
Serial.println("RTC is NOT running!");
RTC.adjust(DateTime(__DATE__, __TIME__));
Serial.println(__TIME__);
}
SSD1306.begin(SSD1306_SWITCHCAPVCC); // fire up OLED display
pinMode(segmentClock, OUTPUT);
pinMode(segmentData, OUTPUT);
pinMode(segmentLatch, OUTPUT);
digitalWrite(segmentClock, LOW);
digitalWrite(segmentData, LOW);
digitalWrite(segmentLatch, LOW);
}
// SIGNAL(TIMER0_COMPA_vect) {char c = GPS.read();} // Read GPS port
void loop() {
DateTime now = RTC.now();
digit1 = now.hour()/10; // 02 = 0 18 = 1
digit2 = now.hour()%10; // 02 = 2 18 = 8
digit3 = now.minute()/10;
digit4 = now.minute()%10;
digit5 = now.second()/10;
digit6 = now.second()%10;
hhmmss = (digit1*100000)+ // lets parse out to drive the digits
(digit2*10000)+ // with leading zeros if necessary
(digit3*1000)+
(digit4*100)+
(digit5*10)+
(digit6*1);
showTime(hhmmss);
sprintf(TimeString, "%02d%02d%02d", now.hour(), now.minute(), now.second()); // format time for OLED
float tempC = (RTC.getTempAsFloat()); // pull temperature from Chronodot (in C)
float tempF = ((tempC * 9 ) / 5) + 32; // convert celsius to Fahrenheit
char tempCStr[10];
dtostrf(tempC, 5, 1, tempCStr); // convert float to 1 dec place
char tempFStr[10];
dtostrf(tempF, 5, 1, tempFStr); // convert float to 1 dec place
char tempString[20];
sprintf(TempString, "%s C | %s F", tempCStr, tempFStr); // format temp readings for OLED
SSD1306.setTextSize(2);
SSD1306.setTextColor(WHITE);
SSD1306.clearDisplay();
SSD1306.setCursor(0,0);
SSD1306.print(TimeString);
SSD1306.setCursor(0,20);
SSD1306.print(TempString);
SSD1306.display(); // push print messages to OLED display
Serial.print(now.hour(), DEC); Serial.print(":"); // debug messages to serial monitor
Serial.print(now.minute(), DEC); Serial.print(":");
Serial.print(now.second(), DEC); Serial.print(" | ");
Serial.print(now.month(), DEC); Serial.print('/');
Serial.print(now.day(), DEC); Serial.print('/');
Serial.print(now.year(), DEC); Serial.print(" | ");
Serial.print(tempC, DEC); Serial.print("C | ");
Serial.print(tempF, DEC); Serial.print("F | ");
Serial.print("Assembly: "); Serial.print(digit1); Serial.print("|");
Serial.print(digit2); Serial.print("|");
Serial.print(digit3); Serial.print("|");
Serial.print(digit4); Serial.print("|");
Serial.print(digit5); Serial.print("|");
Serial.print(digit6); Serial.print("|");
Serial.print(hhmmss);
Serial.println();
delay(1000); // 1 second breather
}
void showTime(unsigned long value) {
unsigned long number = abs(value);
for (byte x = 0 ; x < 6 ; x++) {
int remainder = number % 10;
postNumber(remainder, false);
number /= 10;
}
digitalWrite(segmentLatch, LOW); // Latch the current segment data
digitalWrite(segmentLatch, HIGH); // Register moves storage on rising RCK edge of
}
void postNumber(byte number, boolean decimal) { // push digits out to BIG LEDs
#define a 1<<0 // --- a 0 mapped segments to pins
#define b 1<<6 // 1 f | | b 6
#define c 1<<5 // --- g 2
#define d 1<<4 // 3 e | | c 5
#define e 1<<3 // --- d 4 .DP 7
#define f 1<<1
#define g 1<<2
#define dp 1<<7
byte segments;
switch (number) {
case 1: segments = b | c; break;
case 2: segments = a | b | d | e | g; break;
case 3: segments = a | b | c | d | g; break;
case 4: segments = f | g | b | c; break;
case 5: segments = a | f | g | c | d; break;
case 6: segments = a | f | g | e | c | d; break;
case 7: segments = a | b | c; break;
case 8: segments = a | b | c | d | e | f | g; break;
case 9: segments = a | b | c | d | f | g; break;
case 0: segments = a | b | c | d | e | f; break;
case ' ': segments = 0; break;
case 'c': segments = g | e | d; break;
case '-': segments = g; break;
}
if (decimal) segments |= dp;
for (byte x = 0 ; x < 8 ; x++) { // clock these bits out to the drivers
digitalWrite(segmentClock, LOW);
digitalWrite(segmentData, segments & 1 << (7 - x));
digitalWrite(segmentClock, HIGH); // transfer to register on rising SRCK edge
}
}