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TSOP1738 Vs SM0038 IR Reciever Module

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Suraj143

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Hi all.

I'm interfacing IR module with a PIC.I have enabled weak internal pull-ups (not using any external pull-ups).
The TSOP1738 is working nicely but the Chinese version SM0038 receiver is not working.

Datasheet shows it needs >20K pullup. Does this means I cannot use internal pullups with this?

Do I need to enable weak pull-ups even for TSOP1738?
 

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You do not state which processor you are using. Check the electrical specifications at the end of the datasheet. For the 12F683, the results are:
upload_2015-11-15_3-53-59.png


Assuming 250 uA, the equivalent resistance at 5V would be 2X10^4 or 20K. You will need to verify for the processor you are using. However, as pointed out here: https://electronics.stackexchange.c...ernal-pullup-for-input-in-pic-microcontroller we may not know how it is really constructed, if that matters.

John
 
Hi all.

I'm interfacing IR module with a PIC.I have enabled weak internal pull-ups (not using any external pull-ups).
The TSOP1738 is working nicely but the Chinese version SM0038 receiver is not working.

Datasheet shows it needs >20K pullup. Does this means I cannot use internal pullups with this?

Do I need to enable weak pull-ups even for TSOP1738?

Why not simply add a resistor, and see if it works - it would have been faster than posting on here :p
 
I am using PIC12F629.

So do I need to enable internal pull-ups?Or not needed (pull ups will supply by receiver module)?
 
I love these posts :) Do i need a resistor to make it work I keep about 10,000 just to make sure I have the right one laying around when I need it.
And don't forget some cap they come in handy to some of these need one to work right.
The pullup on a a gpio pin can be way higher then 20k I like the added pennie of a resistor it's a 1 cent part.

The tsop said
They are more reliable with one. But then the tsop seam to be better IR modules that's my opinion. I've played with a bunch of these and some just would not work without the output pin pulled up and a cap on the vcc to ground and one on the output.

Oh and I just remembered I made a test on the breadboard with one I removed from a tv and the dang thing worked great with nothing but power and wire to 12f675 but when I soldered the dang thing on a small pcb with maybe 8 inch of wire it did nothing.
cap and pull up and the baby worked fine.
 
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