Lucas Tai-MacArthur / Mbed 2 deprecated mbed_timer

Penn CIS 441/541 Assignment. Fall 2015

Dependencies:   TextLCD mbed

main.cpp@0:068ad2e1c21d, 2015-10-11 (annotated)

Committer:
lucastai
Date:
Sun Oct 11 18:21:22 2015 +0000
Revision:
0:068ad2e1c21d
Final Version;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
lucastai 0:068ad2e1c21d 1 #include "mbed.h"
lucastai 0:068ad2e1c21d 2 #include "LPC17xx.h"
lucastai 0:068ad2e1c21d 3 #include "TextLCD.h"
lucastai 0:068ad2e1c21d 4
lucastai 0:068ad2e1c21d 5 // declare hardware you're going to use, mostly copied from example code in previous assignments / Dagens piazza post
lucastai 0:068ad2e1c21d 6 volatile unsigned short timer_count;
lucastai 0:068ad2e1c21d 7 Serial pc(USBTX, USBRX);
lucastai 0:068ad2e1c21d 8 TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); // rs, e, d4-d7
lucastai 0:068ad2e1c21d 9
lucastai 0:068ad2e1c21d 10 // declare constants used for counting
lucastai 0:068ad2e1c21d 11 int running = 0;
lucastai 0:068ad2e1c21d 12 char mins_tens = '0';
lucastai 0:068ad2e1c21d 13 char mins_ones = '0';
lucastai 0:068ad2e1c21d 14 char seconds_tens = '0';
lucastai 0:068ad2e1c21d 15 char seconds_ones = '0';
lucastai 0:068ad2e1c21d 16 char ms_tens = '0';
lucastai 0:068ad2e1c21d 17 char ms_ones = '0';
lucastai 0:068ad2e1c21d 18
lucastai 0:068ad2e1c21d 19
lucastai 0:068ad2e1c21d 20 // hardware interrupt handler, adapted from code in piazza post by Dagaen
lucastai 0:068ad2e1c21d 21 extern "C" void TIMER0_IRQHandler (void)
lucastai 0:068ad2e1c21d 22 {
lucastai 0:068ad2e1c21d 23 if((LPC_TIM0->IR & 0x01) == 0x01) // if MR0 interrupt, proceed
lucastai 0:068ad2e1c21d 24 {
lucastai 0:068ad2e1c21d 25 LPC_TIM0->IR |= 1 << 0; // Clear MR0 interrupt flag
lucastai 0:068ad2e1c21d 26 timer_count++; //increment timer_count
lucastai 0:068ad2e1c21d 27 }
lucastai 0:068ad2e1c21d 28 }
lucastai 0:068ad2e1c21d 29
lucastai 0:068ad2e1c21d 30 // init the hardware interrupt (timer0), adapted same as above
lucastai 0:068ad2e1c21d 31 void timer0_init(void)
lucastai 0:068ad2e1c21d 32 {
lucastai 0:068ad2e1c21d 33 LPC_SC->PCONP |=1<1; //timer0 power on
lucastai 0:068ad2e1c21d 34 LPC_SC-> PCLKSEL0 |= 1 << 2; // set timer clock to CCLCK nondivided (1 clock cycle = 1 increment)
lucastai 0:068ad2e1c21d 35 LPC_TIM0->MR0 = 1000000; //100mhz clock cycle, 1 cycle = 10ns, 10ms = 10 000 000 ns = 1M cycles
lucastai 0:068ad2e1c21d 36 LPC_TIM0->MCR = 3; //interrupt and reset control
lucastai 0:068ad2e1c21d 37 //3 = Interrupt & reset timer0 on match (111) sets all three bits
lucastai 0:068ad2e1c21d 38 NVIC_EnableIRQ(TIMER0_IRQn); //enable timer0 interrupt
lucastai 0:068ad2e1c21d 39 }
lucastai 0:068ad2e1c21d 40
lucastai 0:068ad2e1c21d 41 // update the display with the global timer values
lucastai 0:068ad2e1c21d 42 void update_display(void){
lucastai 0:068ad2e1c21d 43 // initialize the display, start at 0, paused
lucastai 0:068ad2e1c21d 44 // first MM
lucastai 0:068ad2e1c21d 45 lcd.locate(0,0);
lucastai 0:068ad2e1c21d 46 lcd.putc(mins_tens);
lucastai 0:068ad2e1c21d 47 lcd.locate(1,0);
lucastai 0:068ad2e1c21d 48 lcd.putc(mins_ones);
lucastai 0:068ad2e1c21d 49 // then :
lucastai 0:068ad2e1c21d 50 lcd.locate(2,0);
lucastai 0:068ad2e1c21d 51 lcd.putc(':');
lucastai 0:068ad2e1c21d 52 // then SS
lucastai 0:068ad2e1c21d 53 lcd.locate(3,0);
lucastai 0:068ad2e1c21d 54 lcd.putc(seconds_tens);
lucastai 0:068ad2e1c21d 55 lcd.locate(4,0);
lucastai 0:068ad2e1c21d 56 lcd.putc(seconds_ones);
lucastai 0:068ad2e1c21d 57 // then :
lucastai 0:068ad2e1c21d 58 lcd.locate(5,0);
lucastai 0:068ad2e1c21d 59 lcd.putc(':');
lucastai 0:068ad2e1c21d 60 // then mS
lucastai 0:068ad2e1c21d 61 lcd.locate(6,0);
lucastai 0:068ad2e1c21d 62 lcd.putc(ms_tens);
lucastai 0:068ad2e1c21d 63 lcd.locate(7,0);
lucastai 0:068ad2e1c21d 64 lcd.putc(ms_ones);
lucastai 0:068ad2e1c21d 65 }
lucastai 0:068ad2e1c21d 66
lucastai 0:068ad2e1c21d 67 // reset global values to 0
lucastai 0:068ad2e1c21d 68 void reset(void){
lucastai 0:068ad2e1c21d 69 mins_tens = '0';
lucastai 0:068ad2e1c21d 70 mins_ones = '0';
lucastai 0:068ad2e1c21d 71 seconds_tens = '0';
lucastai 0:068ad2e1c21d 72 seconds_ones = '0';
lucastai 0:068ad2e1c21d 73 ms_tens = '0';
lucastai 0:068ad2e1c21d 74 ms_ones = '0';
lucastai 0:068ad2e1c21d 75 }
lucastai 0:068ad2e1c21d 76
lucastai 0:068ad2e1c21d 77 // hw interrupt callback, deal with the keyboard input from PC
lucastai 0:068ad2e1c21d 78 void kb_interrupt() {
lucastai 0:068ad2e1c21d 79
lucastai 0:068ad2e1c21d 80 // get the char, put it on the PC command line
lucastai 0:068ad2e1c21d 81 char a = pc.getc();
lucastai 0:068ad2e1c21d 82 pc.putc(a);
lucastai 0:068ad2e1c21d 83 // if the char is S, make sure TCR's relevant bit is set
lucastai 0:068ad2e1c21d 84 if(a == 's'){
lucastai 0:068ad2e1c21d 85 // start timer
lucastai 0:068ad2e1c21d 86 running = 1;
lucastai 0:068ad2e1c21d 87 LPC_TIM0->TCR |= 1 << 0;
lucastai 0:068ad2e1c21d 88 // if the char is p, clear TCR, pausing the timer
lucastai 0:068ad2e1c21d 89 }else if (a == 'p'){
lucastai 0:068ad2e1c21d 90 LPC_TIM0->TCR = 0;
lucastai 0:068ad2e1c21d 91 running = 0;
lucastai 0:068ad2e1c21d 92 // if the char is r, reset the timer, potentially update display independent of clk interrupt if stopped
lucastai 0:068ad2e1c21d 93 }else if (a == 'r'){
lucastai 0:068ad2e1c21d 94 reset();
lucastai 0:068ad2e1c21d 95 if(!running){
lucastai 0:068ad2e1c21d 96 update_display();
lucastai 0:068ad2e1c21d 97 }
lucastai 0:068ad2e1c21d 98 }else{
lucastai 0:068ad2e1c21d 99 // do nothing for invalid char
lucastai 0:068ad2e1c21d 100 }
lucastai 0:068ad2e1c21d 101 }
lucastai 0:068ad2e1c21d 102
lucastai 0:068ad2e1c21d 103
lucastai 0:068ad2e1c21d 104 int main (void)
lucastai 0:068ad2e1c21d 105 {
lucastai 0:068ad2e1c21d 106
lucastai 0:068ad2e1c21d 107 // connect the serial device (PC keybd) to the interrupt
lucastai 0:068ad2e1c21d 108 pc.attach(&kb_interrupt);
lucastai 0:068ad2e1c21d 109
lucastai 0:068ad2e1c21d 110 // reset the counters, display the original 00:00:00 state
lucastai 0:068ad2e1c21d 111 reset();
lucastai 0:068ad2e1c21d 112 update_display();
lucastai 0:068ad2e1c21d 113
lucastai 0:068ad2e1c21d 114
lucastai 0:068ad2e1c21d 115 //init vars, start timer
lucastai 0:068ad2e1c21d 116 timer_count = 0;
lucastai 0:068ad2e1c21d 117 timer0_init();
lucastai 0:068ad2e1c21d 118
lucastai 0:068ad2e1c21d 119 // main program loop
lucastai 0:068ad2e1c21d 120 while(true){
lucastai 0:068ad2e1c21d 121 // on 10ms interrupt
lucastai 0:068ad2e1c21d 122 if(timer_count){
lucastai 0:068ad2e1c21d 123 // set timer count to 0 every 10ms
lucastai 0:068ad2e1c21d 124 timer_count = 0;
lucastai 0:068ad2e1c21d 125
lucastai 0:068ad2e1c21d 126 // count up on 10ms interrupt, make sure counter updates properly
lucastai 0:068ad2e1c21d 127
lucastai 0:068ad2e1c21d 128 // update ms ones
lucastai 0:068ad2e1c21d 129 int msones_carry_flag = 0;
lucastai 0:068ad2e1c21d 130 if(ms_ones == '9'){
lucastai 0:068ad2e1c21d 131 ms_ones = '0';
lucastai 0:068ad2e1c21d 132 msones_carry_flag = 1;
lucastai 0:068ad2e1c21d 133 }else{
lucastai 0:068ad2e1c21d 134 ms_ones++;
lucastai 0:068ad2e1c21d 135 }
lucastai 0:068ad2e1c21d 136
lucastai 0:068ad2e1c21d 137 // update ms tens
lucastai 0:068ad2e1c21d 138 int mstens_carry_flag = 0;
lucastai 0:068ad2e1c21d 139 if(msones_carry_flag){
lucastai 0:068ad2e1c21d 140 if(ms_tens == '9'){
lucastai 0:068ad2e1c21d 141 ms_tens = '0';
lucastai 0:068ad2e1c21d 142 mstens_carry_flag = 1;
lucastai 0:068ad2e1c21d 143 }else{
lucastai 0:068ad2e1c21d 144 ms_tens++;
lucastai 0:068ad2e1c21d 145 }
lucastai 0:068ad2e1c21d 146 }
lucastai 0:068ad2e1c21d 147
lucastai 0:068ad2e1c21d 148 // update sec ones
lucastai 0:068ad2e1c21d 149 int seconds_ones_carry_flag = 0;
lucastai 0:068ad2e1c21d 150 if(mstens_carry_flag){
lucastai 0:068ad2e1c21d 151 if(seconds_ones == '9'){
lucastai 0:068ad2e1c21d 152 seconds_ones = '0';
lucastai 0:068ad2e1c21d 153 seconds_ones_carry_flag = 1;
lucastai 0:068ad2e1c21d 154 }else{
lucastai 0:068ad2e1c21d 155 seconds_ones++;
lucastai 0:068ad2e1c21d 156 }
lucastai 0:068ad2e1c21d 157 }
lucastai 0:068ad2e1c21d 158
lucastai 0:068ad2e1c21d 159 // update sec tens
lucastai 0:068ad2e1c21d 160 int seconds_tens_carry_flag = 0;
lucastai 0:068ad2e1c21d 161 if(seconds_ones_carry_flag){
lucastai 0:068ad2e1c21d 162 if(seconds_tens == '5'){
lucastai 0:068ad2e1c21d 163 seconds_tens = '0';
lucastai 0:068ad2e1c21d 164 seconds_tens_carry_flag = 1;
lucastai 0:068ad2e1c21d 165 }else{
lucastai 0:068ad2e1c21d 166 seconds_tens++;
lucastai 0:068ad2e1c21d 167 }
lucastai 0:068ad2e1c21d 168 }
lucastai 0:068ad2e1c21d 169
lucastai 0:068ad2e1c21d 170 // update mins ones
lucastai 0:068ad2e1c21d 171 int mins_ones_carry_flag = 0;
lucastai 0:068ad2e1c21d 172 if(seconds_tens_carry_flag){
lucastai 0:068ad2e1c21d 173 if(mins_ones == '9'){
lucastai 0:068ad2e1c21d 174 mins_ones = '0';
lucastai 0:068ad2e1c21d 175 mins_ones_carry_flag = 1;
lucastai 0:068ad2e1c21d 176 }else{
lucastai 0:068ad2e1c21d 177 mins_ones++;
lucastai 0:068ad2e1c21d 178 }
lucastai 0:068ad2e1c21d 179 }
lucastai 0:068ad2e1c21d 180
lucastai 0:068ad2e1c21d 181 // update mins tens
lucastai 0:068ad2e1c21d 182 if(mins_ones_carry_flag){
lucastai 0:068ad2e1c21d 183 if(mins_ones == '9'){
lucastai 0:068ad2e1c21d 184 mins_ones = '0';
lucastai 0:068ad2e1c21d 185 mins_ones_carry_flag = 1;
lucastai 0:068ad2e1c21d 186 }else{
lucastai 0:068ad2e1c21d 187 mins_ones++;
lucastai 0:068ad2e1c21d 188 }
lucastai 0:068ad2e1c21d 189 }
lucastai 0:068ad2e1c21d 190
lucastai 0:068ad2e1c21d 191 // update display with new vals
lucastai 0:068ad2e1c21d 192 update_display();
lucastai 0:068ad2e1c21d 193
lucastai 0:068ad2e1c21d 194 }
lucastai 0:068ad2e1c21d 195
lucastai 0:068ad2e1c21d 196 }
lucastai 0:068ad2e1c21d 197 }