main.cpp

00001 /**************************************************************************
00002 *                                                                         *
00003 *   A stripped down simple seven segement example for RedBED              *
00004 *                                                                         *
00005 *   The LED block actually has 8 illuminable sections                     *
00006 *   segments 'a' to 'g' for the main display and 'p' for a decimal point  *
00007 *      _________                                                          *
00008 *     <____a____>                                                         *
00009 *   / \          / \                                                      *
00010 *   | |          | |                                                      *
00011 *   |f|          |b|                                                      *
00012 *   | |          | |                                                      *
00013 *   \ /_________ \ /                                                      *
00014 *     <____g____>                                                         *
00015 *   / \          / \                                                      *
00016 *   | |          | |                                                      *
00017 *   |e|          |c|                                                      *
00018 *   | |          | |                                                      *
00019 *   \ /_________ \ /                                                      *
00020 *     <____d____>     |p|                                                 *
00021 *                                                                         *
00022 **************************************************************************/
00023 
00024 #include "mbed.h"
00025 
00026 uint8_t left = 0;
00027 uint8_t right = 1;
00028 
00029 //The 8 segment outputs and com to switch between the LEDs
00030 DigitalOut seg_a(P1_23), seg_b(P1_28), seg_c(P0_16), seg_d(P1_31), seg_e(P1_13), seg_f(P1_16), seg_g(P1_19), seg_p(P0_23), com(P1_25);
00031 
00032 /******************************************************
00033 *   Set each of the segments for a desired LED        *
00034 ******************************************************/
00035 void SetSegments(uint8_t led, uint8_t a, uint8_t b, uint8_t c, uint8_t d, uint8_t e, uint8_t f, uint8_t g, uint8_t p)
00036 {
00037     //Set desired LED to update
00038     com = led;
00039     
00040     //Update the segments to the desired values.
00041     //the loop ensures the segments are on for an amount 
00042     //of time before being switched off again.
00043     for(uint8_t i = 0; i < 100; i++) 
00044     {
00045         seg_a = 1 - a; //setting a segment to 1 means off 
00046         seg_b = 1 - b; //so invert all requested segment values
00047         seg_c = 1 - c;
00048         seg_d = 1 - d;
00049         seg_e = 1 - e;
00050         seg_f = 1 - f;
00051         seg_g = 1 - g;
00052         seg_p = 1 - p;
00053     }
00054     
00055     //Finally switch off all segments again, we must do this otherwise when
00056     //switching com the segments will be momentarily duplicated from this led.
00057     seg_a = seg_b = seg_c = seg_d = seg_e = seg_f = seg_g = seg_p = 1;
00058 }
00059 
00060 /******************************************************
00061 *   Main loop repeatedly updates each of the LEDs     *
00062 ******************************************************/
00063 int main()
00064 {
00065     for(;;) 
00066     {
00067         //Set the display to read '42'
00068         SetSegments(left,  0,1,1,0,0,1,1,0); //4
00069         SetSegments(right, 1,1,0,1,1,0,1,0); //2
00070     }
00071 }
00072