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01-03-2005, 11:07 PM
Hey hi vikas
I am preparing for micromouse and i am facing some kind of problem using TSOP1738 with IR led.........although my circuit is complete for it and it's correct according to me but i don't knw why the circuit is not working.....now i am very much frustated and don't know what to do.....can u clarify me few things-
1. what shd be the o/p volt when input is +5v
2. what is the minmum volt for IR led andd what should be the threshold for TSOP
and pls pls pls pls mail me the actual ckt if possible @ aggy_28@sify.com
pls help me.........if possible can u gimme ur number so that i can talk 2 u

01-04-2005, 01:09 PM
There is not much to the circuit ...

Still if you dont get it right then something is not working .. give me a call and lets see what i can do

01-04-2005, 10:22 PM
hey vikas....now the problem i am facing is that when i am sending a freq of 38KHZ to the IR Led then it's working fine then that is not detected by TSOP 1738 i.e. it has a continuos voltage at it's output......i don't have ur number so pls gimme ur number so that i can call u.....waise i m from DCE,Delhi

01-04-2005, 11:02 PM
U can use the transmitter circuit given in the Nov issue of EFY pg 68. I tried it and it works. but i made few changes to it , i used polyester capacitors instead of ceramic ones and also i connected the pin 3 directly to the ir led throu' only 22 ohm resistor.

01-07-2005, 10:07 AM
tsop1738 is used only or burst frequencies so if u send some continuous frequencies it will filter it out.

singal it by introducing some delays.

there should be a voltage drop when the signal is detected

05-12-2008, 01:52 PM
Hey....I had a bit of trouble starting up but when finally they work they are pretty good.

A few suggestions...
1.~4.7uF capacitor directly across the terminals of the TSOP
2.design IR led drive so that current abt 70mA when switched on(~1.3V across IR diode)
3.As suggested the pulses should not be a continuous train....
cosider doing this if using for wall detection etc
keep th led switched on for abt 40~60 cycles of 38khz beam and switch of
try doing it by connection another 555 oscillator with desired fq to the reset pin of your 38khz generator(i am assuming you are using a 555 circiut).And use the reset pi of the second IC to start and stopn pulses

some time you might find that the output switches on(goes low )for a small time and the again off with continuous pulse.if yes try varying the fq of the second oscillator

06-04-2008, 08:20 PM
Best way to handle TSOP 1738 is to generate serial data at 1200 baud rate & then modulate 38 Khz from 555 by this data...

This provides app Burst timings needed...

Must check 38 Khz on Dso & Ir led with cam...

This might help as tsop requires some rest time after continous burst of data which is provided by low bit in UART...

:) :)

10-24-2008, 08:04 PM
hi all,
I am currently working on a micromouse.
I have done a simple LFR before and used IR LED-Photodiode for sensing.

I know of TSOP as a 38Khz carrier detector and i like its ambient light protection and range.

I want my micromouse to have sensors that:
1)could tell relatively at wat distance the mouse is from the side walls
2)they should detect wall at a distance of 18cm
3) and should not be sensitive to ambient light.

TSOP does not satisfy the first one as i think it gives digital output(highs and lows)but except that they have a good range and ambient light protection.

Now One basic question:
CAN we use TSOP1738 for ranging distance for application in micromouse????
If yes how and if no then where can it be used in micromouse.

how did u use TSOP in micromouse??