TSOP1738 Vs SM0038 IR Reciever Module

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?

That is the value of the internal pull up resistor?

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:


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

Suraj143 said:

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?

Click to expand...

Why not simply add a resistor, and see if it works - it would have been faster than posting on here

I am using PIC12F629.

So do I need to enable internal pull-ups?Or not needed (pull ups will supply by receiver module)?

I wouldn't consider using an IR module without an external pull-up resistor, as shown in my tutorials:

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

optional

Click to expand...

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.