programming ultrasonic sensors

[Kamkaj]

I have to make a code that should recognize shapes placed in front of a lego robot using two ultrasonic sensors placed vertically ;D. I think both sensors should send the signals at the same time and based on the time reception of the echos, it should be possible for the program to choose different cases. I hope my drawing helps somewhat ;D so the three object will have a different shape. Can anyone give me some clue how to start to write such code? I really have to do this, any advice, beg you.

[Albert.Geven]

I would not use both sensors at the same time but start #2 when #1 is known.Otherwise you don't know which timing belongs to which sensor.

Do you have one sensor working?

[Kamkaj]

That seems like a better concept. I will try this this evening. So I should compare the output value from both sensors and each result give a different case. I'm sure problems will appear so I'll come here again. I have two sensors working but one is nxt and one ev3. I'll get another ev3. Thanks

[Kamkaj]

Hello, So I managed to write a code which recognizes two shapes, (and I need 3) , these two I can below:

I did the comparison of the signals from two ultrasonic sensors, with two cases, by simple comparison block. Like this:

Can I create a third case for the flat shape. It would be when sensors detect echo from both sensors at the same time (more or less). Or maybe there is another way. For example when the echo doesnt return,( I could create something that absorbs ultrasound maybe) Can anyone help me?