File content as of revision 5:019db60eb5a6:

//EE 202 hm2
//This is a program built for the mbed2(slave) in monitor mode
//This code has been tested and should be function, if you has any problem,
//please mail me.
//Author: Yujing Qian
//y.qian42@gmail.com
#include "mbed.h"
#include "MKL46Z4.h"

#define buffer_size 9
DigitalOut LED(LED_RED);
InterruptIn dig_in(PTD4);
Serial pc(USBTX,USBRX);
Serial uart_bbb(PTE16,PTE17);

Serial uart(PTE0, PTE1);

int loop_num=0;
int per_num=0;
int Period=0;
int state=0;
int buffered=0;
uint32_t T2=0;
uint32_t T3=0;
int delay=0;
int per=0;
char buffer[buffer_size];
int buff=0;
int drift_cnt=0;
uint32_t second=0;
bool flag=false;
uint32_t TIME(){
    return (per_num*Period*48000+loop_num*48000+(TPM0->CNT));
    }

void report(){
    int us=(TPM0->CNT);
    uint32_t ms=per_num*Period+loop_num;
    uint32_t s=ms/1000;//second
     ms=ms%1000;
    uart_bbb.printf("n%u:%d\n",s*1000+ms,us);
    pc.printf("n%u:%u:%d\n",s,ms,us);
    drift_cnt++;
    }
void Syc(){// calculate delay using hand shake
            uart.getc();
            uart.putc(0);       
            uart.getc();
            LED=1;
            TPM0->CNT=0;
            TPM0->SC=0x00000048;//0008
    }
void synchronize(){
    //pc.printf("state=%d\n",state);

            buffer[0]=uart.getc();//pc.printf("0=%d\n",buffer[0]);
            uart.putc(0);
            buffer[1]=uart.getc();//pc.printf("1=%d\n",buffer[0]);
            uart.putc(0);
            buffer[2]=uart.getc();//pc.printf("2=%d\n",buffer[0]);
            uart.putc(0);
            buffer[3]=uart.getc();//pc.printf("3=%d\n",buffer[0]);
            uart.putc(0);
            per=((int)buffer[3]<<24)+((int)buffer[2]<<16)+((int)buffer[1]<<8)+((int)buffer[0]);

            Syc();
            
            //pc.printf("Syc_over\n");
            loop_num=0;
            per_num=0;
            Period=per;
            drift_cnt=0;
            second=0;
            flag=true;

    }
    
void TPM0_IRQHandler(void){
            loop_num++;
            if(loop_num==Period){

                LED=!LED;
                per_num++;
                loop_num=0;
            }
            TPM0->SC|= 0x000000c8;
            return;               
    }


void cmd_handler(){
        char tmp;
        if(uart.readable()){
        pc.printf("read\n");
        tmp=uart.getc();
        pc.printf(&tmp);
        
        if(tmp=='#')uart.putc(0);synchronize();}
    
    }

    

void Initial(){
    for(int i=0;i<4;i++)buffer[i]=255;
    loop_num=0;
    per_num=0;
    Period=5000;
    //out=0;
    LED=1;
    SIM->SOPT2=0x05000000;
    SIM->SCGC6=0x01000000;//enable TPM 0
    //TPM0->SC=0x0;
    
    TPM0->CNT=0x0;
    TPM0->SC=0x00000040;
    TPM0->MOD=0x0000bb80;
    TPM0->SC=0x00000048;//0008
    

    }
int main() {
    Initial();
        
    pc.baud(9600);
    uart.baud(9600);
    uart_bbb.baud(9600);
    
    NVIC_SetVector(TPM0_IRQn, (uint32_t)&TPM0_IRQHandler);
    NVIC_SetPriority(TPM0_IRQn, 1);
    NVIC_EnableIRQ(TPM0_IRQn);
    
    dig_in.rise(report); 
    uart.attach(& cmd_handler);
}