File content as of revision 0:3667ad9a98cc:

#include "mbed.h"
#include "pt.h"
#include "pt-sem.h"
int touchSense1(void);
int touchSense2(void);
int getTouch(void);
void hostError(void);
void touchError(void);
DigitalOut myled1(LED1);
DigitalOut myled2(LED3);

AnalogIn input1(p20);
AnalogIn input2(p15);

DigitalIn charger1(p19);
DigitalIn charger2(p16);

DigitalOut ground1(p18);
DigitalOut ground2(p17);
Serial pc(USBTX, USBRX); // tx, rx
#define DEBUG 1

static struct pt_sem dataArrived;
static char BUF[1024];
static int  readFromHost(struct pt *pt) {
    char c;
    int i,len,error  ;
    PT_BEGIN(pt);
    PT_WAIT_UNTIL(pt,pc.readable()); //wait until there is a data in the serial port.
    i=0;
    c='k';
    error = 0;
    while (pc.readable() && c!='S')
        c = pc.getc();

    while (pc.readable() && (c != 'E')) {
        if (c != ' ') {
            //             pc.printf(" READ %c\n",c);
            BUF[i++] = c;
            if ((i>1) && (c!='0') &&(c!='1')) {
                hostError();
                error = 1;
            }

        }
        //   pc.printf("READING %c \n",c);
        c = pc.getc();
    }
    BUF[i] = c;
    BUF[i+1]='\0';
    while (pc.readable()) //bufferout rest;
        c=pc.getc();

    len = strlen(BUF)-1; //to make it right offset

    if ((BUF[0]!='S') || (BUF[len] != 'E')) {
        if (!error)
            hostError();
        error = 1;
    }
    if (!error)
        PT_SEM_SIGNAL(pt, &dataArrived);
    PT_END(pt);
}
static int readFromCapacitor(struct pt *pt) {
    PT_BEGIN(pt);
    char mybuf[1024];
    int i, len,error;
    int t_bit, h_bit;
    PT_SEM_WAIT(pt, &dataArrived);
    strcpy(mybuf, BUF);
#ifdef DEBUG
    pc.printf(" Data arrived %s \n",mybuf);
#endif
    i = 1;
    error = 0;
    len = strlen(mybuf)-1;
    while (i<len) {
        t_bit = getTouch();
#ifdef DEBUG
        pc.printf("\n MY TOKEN IS %c and touch is %d\n",mybuf[i],t_bit);
#endif
        if (mybuf[i] == '0')
            h_bit = 0;
        else if (mybuf[i] == '1')
            h_bit = 1;

        if (t_bit != h_bit) {
            touchError();
            error = 1;
        }
        i++;
    }
    if (!error)
        pc.printf("MATCH\n");
    PT_END(pt);
}
static struct pt pt1, pt2;
int main() {
    PT_SEM_INIT(&dataArrived, 0);
    PT_INIT(&pt1);
    PT_INIT(&pt2);
    while (1) {
        readFromHost(&pt1);
        readFromCapacitor(&pt2);
        wait(0.005);
    }
}


int getTouch(void) {
    int sens;
    while (1) {

        sens = 0;
        if (touchSense1()) {
            wait_ms(5);
            while (touchSense1()) {
                //    pc.printf("In touchsense1\n");
                sens = 1;
                wait_ms(100);
            }
            if (sens)
                return 0;
        }

        if (touchSense2()) {
            wait_ms(5);
            while (touchSense2()) {
                //      pc.printf("In touchsense2\n");
                sens = 1;
                wait_ms(100);
            }
            if (sens)
                return 1;
        }
    }
}

int touchSense1(void) {
    float sample;
    ground1 = 0;
    charger1.mode(PullUp);
    charger1.mode(PullNone);
    sample=input1.read();
    if (sample < 0.3) {
        return 1;
    } else {
        return 0;
    }
}

int touchSense2(void) {
    float sample;
    ground2 = 0;
    charger2.mode(PullUp);
    charger2.mode(PullNone);
    sample=input2.read();
    if (sample < 0.3) {
        return 1;
    } else {
        return 0;
    }
}

void hostError() {
    pc.printf("HOST ERROR");
}
void touchError() {
    pc.printf("TOUCH ERROR");
}