Since IC1A is 14 pin package and it uses only 3 pins it makes it lot bigger in physical size.I am aiming to make hardware circuit as small as possible. I have some questions.
Is there any direct replacement chip for that IC smaller (may be 8 pins or less) in size?
Is it possible to use it with ATtiny85 chip for microcontroller ?
How long approximately it takes to transmit a message say temp/humidity reading from a sensor?
How much power it uses to send one such message with temp/humidity?
Sorry I have lot of questions.Hopefully original author jmknapp chimes in.
I created a simple IR transmitter using the ideas in the old Thread that you linked to. I still have the RX side sitting on a shelf but not the Tx so I can't remember how I implemented it. In my case it was the RX side that needed to be small.
I suspect that, with a bit of nifty programming to stop and start the pulses there would be no need for the 74LS02N or any alternative.
The following is just "thinking out loud" and there may be a much more sensible solution ...
Maybe you could connect the Tx pin to Pin2 (external interrupt on an Uno) and create an ISR that turns on or off the train of pulses depending on the state of the Tx pin
