IrDA for the Basic Stamp

Humanoido

Has anyone developed an IrDA remote control code for the Basic
Stamp, so it can communicate with the PCs built in function?

humanoido

Mike Green

You would need an external IrDA controller like the MAX3100 from Maxim/Dallas. This is a UART with IrDA provisions that communicates via an SPI interface which the Stamp can do with SHIFTIN/SHIFTOUT. The timing is very tight with IrDA and the Stamp is not capable of handling the speed without the external interface.

Humanoido

Thanks Mike, very good advice.
I was wondering, since some things have
changed, like the speed of the Basic Stamp,
do you think the new powerful 2px can
now handle the timing?

If possible, I'd like to use just the 2px
without any add on chips.

Thanks,

humanoido

allanlane5

No. The IrDa standard basically converts a 'stock' 2400 baud UART signal into on-off pulses for an IR-LED. The timing for the LED pulses are quite strict for it to work. None of the BS2 flavors would have sufficient speed to 'bit-bang' that from PBasic.

Also, you keep saying "communicate with the PC's built in function" -- function for what? I've never seen a PC's IrDA port used for anything.

Mike Green

Here a good explanation and example using the Stamp: www.emesystems.com/BS2IrDA.htm.

The pulses can be as short as 1.7us and the normal data rate is 115KBaud (although you can use lower rates).
The BS2px can't handle those without external circuitry. The MAX3100 may need a pulse stretcher in the
input circuitry as Tracy mentions in the explanation.

allanlane5

Thanks, Mike, I stand corrected. That's a very nice summary page you linked to there. And thanks to "emesystems" for your continuing help.