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56 lines
1.7 KiB
56 lines
1.7 KiB
3 years ago
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//www.elegoo.com
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//2016.12.12
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// define the LED digit patterns, from 0 - 9
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// 1 = LED on, 0 = LED off, in this order:
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// 74HC595 pin Q0,Q1,Q2,Q3,Q4,Q5,Q6,Q7
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// Mapping to a,b,c,d,e,f,g of Seven-Segment LED
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byte seven_seg_digits[10] = { B11111100, // = 0
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B01100000, // = 1
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B11011010, // = 2
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B11110010, // = 3
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B01100110, // = 4
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B10110110, // = 5
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B10111110, // = 6
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B11100000, // = 7
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B11111110, // = 8
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B11100110 // = 9
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};
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// connect to the ST_CP of 74HC595 (pin 3,latch pin)
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int latchPin = 3;
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// connect to the SH_CP of 74HC595 (pin 4, clock pin)
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int clockPin = 4;
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// connect to the DS of 74HC595 (pin 2)
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int dataPin = 2;
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void setup() {
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// Set latchPin, clockPin, dataPin as output
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pinMode(latchPin, OUTPUT);
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pinMode(clockPin, OUTPUT);
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pinMode(dataPin, OUTPUT);
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}
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// display a number on the digital segment display
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void sevenSegWrite(byte digit) {
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// set the latchPin to low potential, before sending data
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digitalWrite(latchPin, LOW);
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// the original data (bit pattern)
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shiftOut(dataPin, clockPin, LSBFIRST, seven_seg_digits[digit]);
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// set the latchPin to high potential, after sending data
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digitalWrite(latchPin, HIGH);
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}
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void loop() {
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// count from 9 to 0
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for (byte digit = 10; digit > 0; --digit) {
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delay(1000);
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sevenSegWrite(digit - 1);
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}
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// suspend 4 seconds
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delay(3000);
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}
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