I have the following circuit using a TSOP1738 and a simple IR receiver LED (analog):
It's basically:
- a TSOP1738 put to my 5V uC pin, its OUT being read directly by the yellow channel of my oscilloscope
- an analog IR receiver LED in series with a 3kOhm resistor put to the 3V3 uC pin (shorter leg) which is also being read directly by the blue channel of my oscilloscope
I'm using a 38kHz IR remote and doing some experimenting with this setup.
1) If I'm simply pointing the remote directly above the analog IR LED and keep changing height, both the TSOP and analog IR LED respond: TSOP is digital and thus outputs 0V/5V while with the IR LED I can nicely see how it's analog response increases as I get closer to it, here's a pic of what the oscilloscope shows me:
2) If instead I'm either not pointing directly to the IR analog LED or pointing from a height >~1m the IR analog LED does not respond at all or its response is very very insignificant, while the TSOP1738 responds very well even if I point towards the ceiling from 4m away:
My questions:
1) What makes TSOP1738 so different from the analog IR receiver LED regarding sensitivity?
2) How can I increase the sensitivity of the IR analog LED?
3) Can I somehow make TSOP1738 give me analog output?
Notes:
I'm not sure about the exact specifications of the components as I've bought them a while ago (I'm not even sure that's a TSOP1738 but it probably is)
I'm a beginner in electronics, really just understanding mostly only the basics for now (but I'm good with programming in general, including uCs) :)