Duration smaller than 1?

NewName007

lets say i wanted to say
freqout 4, .6, 38500 on a bs2. does that simply work and im missing it or am I doing it wrong? the reason for this is that I would like to use my bs2 or bs2sx to transmit IR, which ofcoarse needs to be able to transmit a frequency for 600 Us for a logic 0. I have already downloaded the text for "IR Remote for the BOE Bot" I did not see anything on actually doing the transmitting, only recieving signals from a tv remote. I also have the Opta Scope and the book with that but i havn't seen anything to show how to do this. And I do not want to buy the Ir transmitter and receiver parrallax has unless its my ONLY option.
Thanks

allanlane5

Nope, "FREQOUT" on the BS2 uses whole numbers. And I believe each unit is 2 mSec each.

Now, "PULSOUT" can do pulses in 2 uSec resolution. Which is why you can use a 555 timer chip to generate the 38Khz signal, and "modulate it" (turn it on and off) with a PULSOUT.

And "PULSIN" can measure to 2 uSec resolution, so that's ok.

Now the BS2sx might be able to do FREQOUT in 600 uSec increments -- but that may not help much.

Chris Savage

Deja Vu...We just had this topic a short while ago...

http://forums.parallax.com/showthread.php?p=552863

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Chris Savage
Parallax Tech Support
csavage@parallax.com

Andy Lindsay (Parallax)

If you need to modulate 38 kHz IR in increments of less than 1 ms, you can use the circuit and example code in this Stamps in Class forum post: Ir remote control w/ BS2

Note: There's an error in the first circuit, but the correct circuit was posted later in the thread.