Yes this is arduino code upon having tried by my self and failed repeatedly i looked around for code that i could use and adapt. Thus i found the arduino code on teachingeneering.org under train 2 sensors. I tried to adapt it to the best of my abilities however i once again failed. In frustration i posted the original arduino code.

I will try my best but as the deadline looms i have become exetremly frustrated.

Arduino has the loop/setup system as in your code, mbed uses standard C(++), which simply has a main function where it starts, if it arrives at the end no one knows what happens (as in, depends on the platform), so generally you make a neverending loop just like arduino, but using while(1) {}.

Anyway the Timer link shows both how Timer is used and how to print the time to Teraterm, make sure that works for you. Then the DigitalIn example simply directly routes an input to one of the onboard leds. Make sure that works with one of your lightgates. If that works we can go to the next step ;)

Thank you i will try this and let you know how it works.

The time is not printed into TeraTerm when i ran the program given in the timer link. However I have made sure that the terminal is linked to the processor. This leaves me at a lose as to what is wrong. I have used the examples you provided to write the following :

1. include "mbed.h"

DigitalIn a(p20); DigitalIn b(p21);

Timer t (); int main () { read() DigitalIn a; while(1) { if(enable) { t.start (); printf("The run commences/n"); read() DigitalIn b; while(1) { if(enable) { t.stop (); printf("Time taken was %f micro-seconds/n", t.read ()); } } } }

It is far from perfect and when i compile the compiler continuasly tells me various things are not properly defined (error 20).

1. Still use <<code>> and <</code>>, you can also see the code otherwise is unreadable.

2. If you get an error, tell which line(s) it is.

3. The error is for now irrelevant. Start with getting the basics working. It makes no sense to start making a more complicated program when your basic program isn't functional.

So you do not get anything in Teraterm when running that program? Do you connect to a serial port with teraterm? Is it labelled mbed? If you type in Teraterm, does the led of your mbed flash?

I do not get anything when running that program and connected to serial port labeled com7: mbed serial port. When i click on the terminal window and type in Teraterm the led on the mbed flashes however nothing appears in the terminal window

That is weird. What are the serial port settings in your teraterm?

port:com7 baud rate:9600 Data: 8 bit Parity: none Stop: 1 bit Flow Control: none Transmitter delay: none

i am out of time i must begin working on the full fledged program science fair is tomorrow. I have tried everything possible to get Teraterm working however it does not

I got teraTerm to work however there seems to be a problem in the program with the timer that would print it's time i used the example program for serial out on the mbed website and everything functioned perfectly

Weird, but good. Now that works, somewhat, can you do the DigitalIn example program, but then with your light gates, to see if that works correctly.

Yes it works fine!!! :-)

Now as something I usually don't do, but for once, I wrote something that probably should work, it compiles at least. But of course I don't have your setup so I cannot test it:

Try:

#include "mbed.h"

Serial pc(USBTX, USBRX);

DigitalIn lightgate1(p20);      //Set correct pin for the top light gate
DigitalIn lightgate2(p21);      //Set correct pin for the bottom light gate
DigitalOut statusLed(LED1);     //Will be high while the target is between the two light gates

Timer timer;

int main() {
    pc.printf("Starting program!\r\n");
    pc.printf("Gate 1 = %d and gate 2 = %d \r\n", lightgate1.read(), lightgate2.read());        //(Without the .read() it gives a warning, this should for sure work)
    while(1) {
        //Reset timer
        timer.reset();
        statusLed = 0;
        pc.printf("Waiting till gate 1 is triggered!\r\n");
        while(lightgate1 == 0);
        
        //Light gate 1 is triggered!
        timer.start();
        statusLed = 1;
        
        while(lightgate2 == 0);
        
        //Light gate 2 is triggered!
        timer.stop();
        statusLed = 0;
        
        pc.printf("Measurement finished\r\n");
        pc.printf("Measured time = %f seconds\r\n", timer.read());
        wait(2);
    }
}

It should print at least something to Teraterm. If it doesn't work, give as much information as possible, mainly what does it print to Teraterm, and if it hangs halfway also the state of the LED.

I am absolutely overjoyed.

So that program works now to measure the time? In that case: :-)

Yes it works brilliantly better than i could ever have imagined it is absolutely fantastic.