Atmega328p IR transceiver with internal oscillator

First off, thanks for any help given as i’ve been slumped on this for a while

First question, what baud rate is minimal for IR demodulation and emitter, my project is very space constrained and is running off a 3.7v battery with a 40ma max discharge current

Second, I know the atmega328p has an internal 8mhz clock but needs to be calibrated for high baud rate applications, so my question is would the baud rate needed require calibration?

Third, if the clock needs to be calibrated(something I’ve tried doing but seem to can’t do), would adding the external 8mhz clock with the 2 extra capacitors go over the 40ma max discharge?

I'll assume by baud rate you mean clock frequency...

A receiver like a Vishay TSOP38238 will use only a few milli-Amps (about 3mA I think) and are not clock dependant. Using the 8 MHz internal oscillator without calibration at 3V works fine for me, transmit and receive.

Most IR LEDs can be driven at 20mA, so it will be a trade-off between range and power consumption.

If you've got something different, a link to a datasheet would help.