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This project is a good beginner Arduino project. I wanted a digital timer in my gym that counted up from 00 to 60 seconds and reset. Since I had a spare Arduino Nano and a dual 7-segment display (rescued from a guitar effect pedal) I decided to build my own instead of driving to Wal-Mart.
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If you are not interested in the details and just want to see the result, check out the video below. If you watch more than the first 10-15 seconds then you should seriously consider getting a hobby. ;)
The dual 7-segment display pinout looks like this. The Arduino Nano has 14 digital outputs and you will need them all. Note: You will have to disconnect D0 and D1 from the dual 7-segment display to get reliable program uploads to the Arduino because these pins double as the USB data connection to your PC.
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And here is the code. Total project including wiring took a bit over two hours and I am a slow coder.
/*
**************************************
***** www.WhiskeyTangoHotel.Com *****
**************************************
Project Name: Gym Counter Timer
Start Date: July 26, 2014
Program Rev History and Notes:
Simple timer to count up 60 secs then reset.
LEDS are active LOW. Low turns the segment on.
LEDS came from old Zoom guitar effects pedal.
NOTE: DISCONNECT D0 AND D1 TO PREVENT U/L ERRORS
***************************************
*/
//All 14 digi pins are needed as outputs to drive two 7-seg displays. Assign aliases
// standard a-g labeling on the 7-segs. The decmial point (DP) is not used.
int a_ones = 0;
int b_ones = 1;
int c_ones = 2;
int d_ones = 3;
int e_ones = 4;
int f_ones = 5;
int g_ones = 6;
int a_tens = 7;
int b_tens = 8;
int c_tens = 9;
int d_tens = 10;
int e_tens = 11;
int f_tens = 12;
int g_tens = 13;
int i;
//**************************************
void setup() // Functions here
{
// Define all digi pins as OUTPUT
pinMode(a_ones, OUTPUT);
pinMode(b_ones, OUTPUT);
pinMode(c_ones, OUTPUT);
pinMode(d_ones, OUTPUT);
pinMode(e_ones, OUTPUT);
pinMode(f_ones, OUTPUT);
pinMode(g_ones, OUTPUT);
pinMode(a_tens, OUTPUT);
pinMode(b_tens, OUTPUT);
pinMode(c_tens, OUTPUT);
pinMode(d_tens, OUTPUT);
pinMode(e_tens, OUTPUT);
pinMode(f_tens, OUTPUT);
pinMode(g_tens, OUTPUT);
// Arduino wakes up with pins low. Set them HI to turn off the LEDS
all_off();
i = 200; // 200 'feels right'. Self test count delay from "00" to "99"
zero_ones();
zero_tens();
delay(i);
all_off();
one_ones();
one_tens();
delay(i);
all_off();
two_ones();
two_tens();
delay(i);
all_off();
three_ones();
three_tens();
delay(i);
all_off();
four_ones();
four_tens();
delay(i);
all_off();
five_ones();
five_tens();
delay(i);
all_off();
six_ones();
six_tens();
delay(i);
all_off();
seven_ones();
seven_tens();
delay(i);
all_off();
eight_ones();
eight_tens();
delay(i);
all_off();
nine_ones();
nine_tens();
delay(i);
all_off();
i = 1000; // Make this one second for count below
} //void setup
//**************************************
void loop() //Loop Forever
{
for (int display_count = 0; display_count <= 59; display_count++){
switch (display_count) { // branch (switch) to case below and display the two digits
case 0:
zero_tens();
zero_ones();
break;
case 1:
zero_tens();
one_ones();
break;
case 2:
zero_tens();
two_ones();
break;
case 3:
zero_tens();
three_ones();
break;
case 4:
zero_tens();
four_ones();
break;
case 5:
zero_tens();
five_ones();
break;
case 6:
zero_tens();
six_ones();
break;
case 7:
zero_tens();
seven_ones();
break;
case 8:
zero_tens();
eight_ones();
break;
case 9:
zero_tens();
nine_ones();
break;
case 10:
one_tens();
zero_ones();
break;
case 11:
one_tens();
one_ones();
break;
case 12:
one_tens();
two_ones();
break;
case 13:
one_tens();
three_ones();
break;
case 14:
one_tens();
four_ones();
break;
case 15:
one_tens();
five_ones();
break;
case 16:
one_tens();
six_ones();
break;
case 17:
one_tens();
seven_ones();
break;
case 18:
one_tens();
eight_ones();
break;
case 19:
one_tens();
nine_ones();
break;
case 20:
two_tens();
zero_ones();
break;
case 21:
two_tens();
one_ones();
break;
case 22:
two_tens();
two_ones();
break;
case 23:
two_tens();
three_ones();
break;
case 24:
two_tens();
four_ones();
break;
case 25:
two_tens();
five_ones();
break;
case 26:
two_tens();
six_ones();
break;
case 27:
two_tens();
seven_ones();
break;
case 28:
two_tens();
eight_ones();
break;
case 29:
two_tens();
nine_ones();
break;
case 30:
three_tens();
zero_ones();
break;
case 31:
three_tens();
one_ones();
break;
case 32:
three_tens();
two_ones();
break;
case 33:
three_tens();
three_ones();
break;
case 34:
three_tens();
four_ones();
break;
case 35:
three_tens();
five_ones();
break;
case 36:
three_tens();
six_ones();
break;
case 37:
three_tens();
seven_ones();
break;
case 38:
three_tens();
eight_ones();
break;
case 39:
three_tens();
nine_ones();
break;
case 40:
four_tens();
zero_ones();
break;
case 41:
four_tens();
one_ones();
break;
case 42:
four_tens();
two_ones();
break;
case 43:
four_tens();
three_ones();
break;
case 44:
four_tens();
four_ones();
break;
case 45:
four_tens();
five_ones();
break;
case 46:
four_tens();
six_ones();
break;
case 47:
four_tens();
seven_ones();
break;
case 48:
four_tens();
eight_ones();
break;
case 49:
four_tens();
nine_ones();
break;
case 50:
five_tens();
zero_ones();
break;
case 51:
five_tens();
one_ones();
break;
case 52:
five_tens();
two_ones();
break;
case 53:
five_tens();
three_ones();
break;
case 54:
five_tens();
four_ones();
break;
case 55:
five_tens();
five_ones();
break;
case 56:
five_tens();
six_ones();
break;
case 57:
five_tens();
seven_ones();
break;
case 58:
five_tens();
eight_ones();
break;
case 59:
five_tens();
nine_ones();
break;
} // case switch statement
delay(i); // i is set above to one second
all_off();
} // for display_count loop
} //void loop
// Function subroutines below to turn on and off the 7-segments
// "_ones" is for the ONES place in the counter. "_tens" is for TENS place in the counter
void zero_ones() {
// segments a b c d e
digitalWrite(a_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(c_ones, 0);
digitalWrite(d_ones, 0);
digitalWrite(e_ones, 0);
digitalWrite(f_ones, 0);
} //zero_ones
void one_ones() {
// segments b c
digitalWrite(b_ones, 0);
digitalWrite(c_ones, 0);
} //ones_ones
void two_ones() {
// segments a b g e d
digitalWrite(a_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(g_ones, 0);
digitalWrite(e_ones, 0);
digitalWrite(d_ones, 0);
} //two_ones
void three_ones() {
// segments a b g c d
digitalWrite(a_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(g_ones, 0);
digitalWrite(c_ones, 0);
digitalWrite(d_ones, 0);
} //three_ones
void four_ones() {
// segments f g b c
digitalWrite(f_ones, 0);
digitalWrite(g_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(c_ones, 0);
} //four_ones
void five_ones() {
// segments a f g c d
digitalWrite(a_ones, 0);
digitalWrite(f_ones, 0);
digitalWrite(g_ones, 0);
digitalWrite(c_ones, 0);
digitalWrite(d_ones, 0);
} //five_ones
void six_ones() {
// segments a f g c d e
digitalWrite(a_ones, 0);
digitalWrite(f_ones, 0);
digitalWrite(g_ones, 0);
digitalWrite(c_ones, 0);
digitalWrite(d_ones, 0);
digitalWrite(e_ones, 0);
} //six_ones
void seven_ones() {
// segments a b c
digitalWrite(a_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(c_ones, 0);
} //seven_ones
void eight_ones() {
// segments a b c d e f g
digitalWrite(a_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(c_ones, 0);
digitalWrite(d_ones, 0);
digitalWrite(e_ones, 0);
digitalWrite(f_ones, 0);
digitalWrite(g_ones, 0);
} //eight_ones
void nine_ones() {
// segments a b c d e f g
digitalWrite(a_ones, 0);
digitalWrite(b_ones, 0);
digitalWrite(c_ones, 0);
digitalWrite(d_ones, 0);
digitalWrite(f_ones, 0);
digitalWrite(g_ones, 0);
} //nine_ones
void zero_tens() {
// segments a b c d e
digitalWrite(a_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(c_tens, 0);
digitalWrite(d_tens, 0);
digitalWrite(e_tens, 0);
digitalWrite(f_tens, 0);
} //zero_tens
void one_tens() {
// segments b c
digitalWrite(b_tens, 0);
digitalWrite(c_tens, 0);
} //ones_tens
void two_tens() {
// segments a b g e d
digitalWrite(a_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(g_tens, 0);
digitalWrite(e_tens, 0);
digitalWrite(d_tens, 0);
} //two_tens
void three_tens() {
// segments a b g c d
digitalWrite(a_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(g_tens, 0);
digitalWrite(c_tens, 0);
digitalWrite(d_tens, 0);
} //three_tens
void four_tens() {
// segments f g b c
digitalWrite(f_tens, 0);
digitalWrite(g_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(c_tens, 0);
} //four_tens
void five_tens() {
// segments a f g c d
digitalWrite(a_tens, 0);
digitalWrite(f_tens, 0);
digitalWrite(g_tens, 0);
digitalWrite(c_tens, 0);
digitalWrite(d_tens, 0);
} //five_tens
void six_tens() {
// segments a f g c d e
digitalWrite(a_tens, 0);
digitalWrite(f_tens, 0);
digitalWrite(g_tens, 0);
digitalWrite(c_tens, 0);
digitalWrite(d_tens, 0);
digitalWrite(e_tens, 0);
} //six_tens
void seven_tens() {
// segments a b c
digitalWrite(a_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(c_tens, 0);
} //seven_tens
void eight_tens() {
// segments a b c d e f g
digitalWrite(a_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(c_tens, 0);
digitalWrite(d_tens, 0);
digitalWrite(e_tens, 0);
digitalWrite(f_tens, 0);
digitalWrite(g_tens, 0);
} //eight_tens
void nine_tens() {
// segments a b c d e f g
digitalWrite(a_tens, 0);
digitalWrite(b_tens, 0);
digitalWrite(c_tens, 0);
digitalWrite(d_tens, 0);
digitalWrite(f_tens, 0);
digitalWrite(g_tens, 0);
} //nine_tens
void all_off() {
digitalWrite(a_ones, 1);
digitalWrite(b_ones, 1);
digitalWrite(c_ones, 1);
digitalWrite(d_ones, 1);
digitalWrite(e_ones, 1);
digitalWrite(f_ones, 1);
digitalWrite(g_ones, 1);
digitalWrite(a_tens, 1);
digitalWrite(b_tens, 1);
digitalWrite(c_tens, 1);
digitalWrite(d_tens, 1);
digitalWrite(e_tens, 1);
digitalWrite(f_tens, 1);
digitalWrite(g_tens, 1);
} // all_off
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Thanks for the visit!
