38Khz IR carrier - best way to turn it on and off

[andywpg]

Thanks Everyone!

It worked!

The answer was a pull down resistor. It got rid of that slope. I tried a few, and worked out that 4.7K was the highest value I could use. That gave me a final voltage about 4.2V which should be fine.

Then I had to play with the frequency I specified to get exactly 38 pulses in 1mS. Even though the scope's measurement function still reports it as 38.46KHz - I told you it was a cheap scope!

Here are two images of what I have now.

Thanks again!

Andy

Attachment 8114