IR communication

[theinevitable]

Hi,

I am working on a university group project which is about designing a lego robot that collects squash balls and deposits them in a basket. The lego components made available for this project are very limited, but we can spend some 30 pounds on some extra non-lego components.

Since we used up all sensor and motor ports we need to use the IR to communicate with the extra components. We got it almost to work but are facing one final, obscure problem:

The rcx only seems to accept packages that consists one of these numbers: 6,8,14, and a few more (I didn't try the entire range). It always turns out to be same numbers. This has nothing to do with our external circuit since the same behaviour is also happening when I try sending the same signals using another RCX running lejos.

The way I pick up the signal is by using the event listener as described in lejos tutorial: Controlling the Hardware: The IR Interface

I have set the range to long. Does anyone know why it fails?

[theinevitable]

Alright, I managed to solve it by sending 0xf7 in the first byte in each package. I don't know why this has to be done though.

[umeshnk]

I'm not sure this will help. But One of my friends has developed a circuit for re-transmitting the IR signal emitted by the RCX IR transmitter. It can transmit the signal 360 degrees. It costs very little. Request if it helps.