need help with IR dtectors and transmitters

[nischal]

hi guys

i am designing a robot to avoid obstacles and for that purpose i would like some information about any particualr circuits using TSOP IR sensor for reciever.....it has been mentioned that the frequency of operation is 38khz.i cudnt understand what it means....and what is burst frequency???

i am new to this site and robotics too and would like all the help i can get pertaining to the above topics and in general too...

thnks

 

[jjimenez101]

I am assuming that you are using a micro-controller for this project? If so, you can try using Sharp's IR sensors, which contain trasmitter and receiver one one small plastic package, you can get them from Acroname:

https://www.acroname.com/robotics/info/articles/sharp/sharp.html

They range in detecting objects from 4cm to about 150cm, depending on the ones you choose. You can easily connect the outputs to an ADC converter and determine if there is an obstacle nearby depending on the voltage level.

 

[philba]

the frequency (38Khz) is a carrier. the transmitter modulates it's output at 38Khz. The tsop looks for the carrier frequency and rejects signals that fall outside of that (+/- 10%, I think). In remote controls, the binary data is modulated onto the carrier. this helps to prevent interference from other IR sources. the tsop strips the carrier and gives you the modulated data.

for obstacle detection, you don't need any data, just the presence or absence of a relection.

 

[nischal]

thxx a ton 2 evr1

thxx evry1 for ur replies.....

 

[ikalogic]

if your application is indoor, this less reliable but simpler solution may help:

**broken link removed**

 

[sonamgotex]

please help me

hi guys,
i am a BE students and i am doing my project on building a robot that can follow the man.So please help me what type of sensors i should use for my robot.
Thanks

 

[max_imum2000]

how about a man sensor
just kidding
i can only think of thermal body detection system that can detect body heat and follow it

 

[panadol]

Nischal,
I am doing somehting like what u needed. I am using TSOP1738 IR receiver, it is really really powerful as it has very high gain in it.
I used a 555timer to produce an output pulses at 38khz.
the problem i have now is that TSOP series of receiver will reject continous signals. I did a test using TV remote control and my transmitter. TV remote is sending bursty data, but my 555 output is continouos. So it order for TSOP to work properly, its either u send a bursty pulse or maybe u can on ur transmitter for only a very short duration.