just a small code example to display numbers on a 7 segment display should be easy to rewrite for your own needs.
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Revision 1:8a3c7884316e, committed 2016-09-03
- Comitter:
- captaintim
- Date:
- Sat Sep 03 17:31:45 2016 +0000
- Parent:
- 0:463ff11d33fa
- Commit message:
- Wrote correction to matrix so it works with pinouts of LDQ-N514R1, a 4 digit, 7-segment display (common cathode)
Changed in this revision
main.cpp | Show annotated file Show diff for this revision Revisions of this file |
--- a/main.cpp Sat Dec 29 12:00:01 2012 +0000 +++ b/main.cpp Sat Sep 03 17:31:45 2016 +0000 @@ -1,38 +1,80 @@ #include "mbed.h" - //pins are sorted from upper left corner of the display to the lower right corner - //the display has a common cathode - //the display actally has 8 led's, the last one is a dot -DigitalOut led[8]={p18, p19, p17, p20, p16, p14, p15, p13}; + /*test program to learn how to write code for a 4 digit, 7-segment LED display LDQ-N524R1 +The schematic for this (COMMON CATHODE) display shows the following connections +schematic located at http://www.lumex.com/ldq-n514ri (open Specs PDF for drawing) +The Common Cathode means that to turn on the segments of the 7-segment (including decimal point) +you write a one to that segment. +For this 4 digit display (LDQ-N524R1), each digit works backward--like its wired Common Anode so +You write a ZERO to turn on the selected digit AND a ONE to turn off the digit. + +Pin Out wiring guide:(connect the display pin # to XX mbed pin) +CONTROL DISPLAY Pin# MBED Pin# +---------------------------------- +Digit1 12 14 +Digit2 9 13 +Digit3 8 12 +Digit4 6 11 +DP 3 10 +A 11 21 +B 7 22 +C 4 23 +D 2 24 +E 1 25 +F 5 26 +G 5 27 + +There is no blanking on this display, - //each led that has to light up gets a 1, every other led gets a 0 - //its in order of the DigitalOut Pins above -int number[11][8]={ - {1,1,1,0,1,1,1,0}, //zero - {0,0,1,0,0,1,0,0}, //one - {1,0,1,1,1,0,1,0}, //two - {1,0,1,1,0,1,1,0}, //three - {0,1,1,1,0,1,0,0}, //four - {1,1,0,1,0,1,1,0}, //five - {1,1,0,1,1,1,1,0}, //six - {1,0,1,0,0,1,0,0}, //seven +Program demonstrates writing to one 7-segment display of 4 digit display LDQ-N514R1 +Author: Cap'n Tim Johnson PE +Retired Professor +Wentworth Institude of Technology +Dept. Electrical Engineering and Technology +Boston, MA +*/ + +//Setup: +DigitalOut Digit1(p14); //construct to control digits +DigitalOut Digit2(p13); +DigitalOut Digit3(p12); +DigitalOut Digit4(p11); + +//these are the pins associated with writing to the "led" +DigitalOut led[8]={p21, p22, p23, p24, p25, p26, p27, p10}; + +//segments are in alphabetical order a-g, followed by Decimal point in the array below + +int matrix[11][8]={ + {1,1,1,1,1,1,0,0}, //zero + {0,1,1,0,0,0,0,0}, //one + {1,1,0,1,1,0,1,0}, //two + {1,1,1,1,0,0,1,0}, //three + {0,1,1,0,0,1,1,0}, //four + {1,0,1,1,0,1,1,0}, //five + {1,0,1,1,1,1,1,0}, //six + {1,1,1,0,0,0,0,0}, //seven {1,1,1,1,1,1,1,0}, //eight - {1,1,1,1,0,1,1,0}, //nine + {1,1,1,0,0,1,1,0}, //nine {0,0,0,0,0,0,0,1} //dot }; int main() { + Digit1 = 1; //turn all digit1 in case they've been turned on...in another program + Digit2 = 1; //turn off digit2 + Digit3 = 1; //turn off digit3 + Digit4 = 1; //turn off digit4 + + Digit1 = 0; //Turn on digit#1, Most Significant Digit while (1) { //all led's off for(int i = 0; i<8;i++){led[i] = 0;} //display shows the number in this case 6 - for (int i=0; i<8; i++){led[i] = number[6][i];} //the digit after "number" is displayed - - //before it gets tired - wait(0.5); + for (int i=0; i<8; i++){led[i] = matrix[6][i];} //holds row of "number" and assign column value from matrix + wait(0.5); } -} \ No newline at end of file +}