Lucas Tai-MacArthur
Penn CIS 441/541 Assignment. Fall 2015
Revision 0:068ad2e1c21d, committed 2015-10-11
- Comitter:
- lucastai
- Date:
- Sun Oct 11 18:21:22 2015 +0000
- Commit message:
- Final Version;
Changed in this revision
diff -r 000000000000 -r 068ad2e1c21d TextLCD.lib --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/TextLCD.lib Sun Oct 11 18:21:22 2015 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/simon/code/TextLCD/#308d188a2d3a
diff -r 000000000000 -r 068ad2e1c21d main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Oct 11 18:21:22 2015 +0000
@@ -0,0 +1,197 @@
+#include "mbed.h"
+#include "LPC17xx.h"
+#include "TextLCD.h"
+
+// declare hardware you're going to use, mostly copied from example code in previous assignments / Dagens piazza post
+volatile unsigned short timer_count;
+Serial pc(USBTX, USBRX);
+TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); // rs, e, d4-d7
+
+// declare constants used for counting
+int running = 0;
+char mins_tens = '0';
+char mins_ones = '0';
+char seconds_tens = '0';
+char seconds_ones = '0';
+char ms_tens = '0';
+char ms_ones = '0';
+
+
+// hardware interrupt handler, adapted from code in piazza post by Dagaen
+extern "C" void TIMER0_IRQHandler (void)
+{
+if((LPC_TIM0->IR & 0x01) == 0x01) // if MR0 interrupt, proceed
+ {
+ LPC_TIM0->IR |= 1 << 0; // Clear MR0 interrupt flag
+ timer_count++; //increment timer_count
+ }
+}
+
+// init the hardware interrupt (timer0), adapted same as above
+void timer0_init(void)
+{
+ LPC_SC->PCONP |=1<1; //timer0 power on
+ LPC_SC-> PCLKSEL0 |= 1 << 2; // set timer clock to CCLCK nondivided (1 clock cycle = 1 increment)
+ LPC_TIM0->MR0 = 1000000; //100mhz clock cycle, 1 cycle = 10ns, 10ms = 10 000 000 ns = 1M cycles
+ LPC_TIM0->MCR = 3; //interrupt and reset control
+ //3 = Interrupt & reset timer0 on match (111) sets all three bits
+ NVIC_EnableIRQ(TIMER0_IRQn); //enable timer0 interrupt
+}
+
+// update the display with the global timer values
+void update_display(void){
+ // initialize the display, start at 0, paused
+ // first MM
+ lcd.locate(0,0);
+ lcd.putc(mins_tens);
+ lcd.locate(1,0);
+ lcd.putc(mins_ones);
+ // then :
+ lcd.locate(2,0);
+ lcd.putc(':');
+ // then SS
+ lcd.locate(3,0);
+ lcd.putc(seconds_tens);
+ lcd.locate(4,0);
+ lcd.putc(seconds_ones);
+ // then :
+ lcd.locate(5,0);
+ lcd.putc(':');
+ // then mS
+ lcd.locate(6,0);
+ lcd.putc(ms_tens);
+ lcd.locate(7,0);
+ lcd.putc(ms_ones);
+}
+
+// reset global values to 0
+void reset(void){
+ mins_tens = '0';
+ mins_ones = '0';
+ seconds_tens = '0';
+ seconds_ones = '0';
+ ms_tens = '0';
+ ms_ones = '0';
+}
+
+// hw interrupt callback, deal with the keyboard input from PC
+void kb_interrupt() {
+
+ // get the char, put it on the PC command line
+ char a = pc.getc();
+ pc.putc(a);
+ // if the char is S, make sure TCR's relevant bit is set
+ if(a == 's'){
+ // start timer
+ running = 1;
+ LPC_TIM0->TCR |= 1 << 0;
+ // if the char is p, clear TCR, pausing the timer
+ }else if (a == 'p'){
+ LPC_TIM0->TCR = 0;
+ running = 0;
+ // if the char is r, reset the timer, potentially update display independent of clk interrupt if stopped
+ }else if (a == 'r'){
+ reset();
+ if(!running){
+ update_display();
+ }
+ }else{
+ // do nothing for invalid char
+ }
+}
+
+
+int main (void)
+{
+
+ // connect the serial device (PC keybd) to the interrupt
+ pc.attach(&kb_interrupt);
+
+ // reset the counters, display the original 00:00:00 state
+ reset();
+ update_display();
+
+
+ //init vars, start timer
+ timer_count = 0;
+ timer0_init();
+
+ // main program loop
+ while(true){
+ // on 10ms interrupt
+ if(timer_count){
+ // set timer count to 0 every 10ms
+ timer_count = 0;
+
+ // count up on 10ms interrupt, make sure counter updates properly
+
+ // update ms ones
+ int msones_carry_flag = 0;
+ if(ms_ones == '9'){
+ ms_ones = '0';
+ msones_carry_flag = 1;
+ }else{
+ ms_ones++;
+ }
+
+ // update ms tens
+ int mstens_carry_flag = 0;
+ if(msones_carry_flag){
+ if(ms_tens == '9'){
+ ms_tens = '0';
+ mstens_carry_flag = 1;
+ }else{
+ ms_tens++;
+ }
+ }
+
+ // update sec ones
+ int seconds_ones_carry_flag = 0;
+ if(mstens_carry_flag){
+ if(seconds_ones == '9'){
+ seconds_ones = '0';
+ seconds_ones_carry_flag = 1;
+ }else{
+ seconds_ones++;
+ }
+ }
+
+ // update sec tens
+ int seconds_tens_carry_flag = 0;
+ if(seconds_ones_carry_flag){
+ if(seconds_tens == '5'){
+ seconds_tens = '0';
+ seconds_tens_carry_flag = 1;
+ }else{
+ seconds_tens++;
+ }
+ }
+
+ // update mins ones
+ int mins_ones_carry_flag = 0;
+ if(seconds_tens_carry_flag){
+ if(mins_ones == '9'){
+ mins_ones = '0';
+ mins_ones_carry_flag = 1;
+ }else{
+ mins_ones++;
+ }
+ }
+
+ // update mins tens
+ if(mins_ones_carry_flag){
+ if(mins_ones == '9'){
+ mins_ones = '0';
+ mins_ones_carry_flag = 1;
+ }else{
+ mins_ones++;
+ }
+ }
+
+ // update display with new vals
+ update_display();
+
+ }
+
+ }
+}
\ No newline at end of file
diff -r 000000000000 -r 068ad2e1c21d mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sun Oct 11 18:21:22 2015 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/34e6b704fe68 \ No newline at end of file