It's just a standard logic level output, you can connect it directly to an I/O pin on the PIC - check my tutorials for exact details - it's ESSENTIAL to include the decoupling capacitor and resistor in the power feed to the receiver, or you get seriously strange problems!. There's no programming involved with the sensor, only of the data you send over it.

You can't really do anything to the receive side to increase range, you need to increase the transmit power - multiple LED's, higher power pulses, more accurately focused (using narrower beamwidth LED's).

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thanks, i do get to your tutorials site (but yet i still could not find any details about the sensor, can you show me the direct link?) and i found that the coding that you used is different from mine. i am using microcode studio plus to write and compile my program. winpic800 to burn my program into the PIC.

 

Try http://www.winpicprog.co.uk/pic_tutorial_ir_board.htm

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hi, sorry to interrupt.
im also building something like what mr.compass is building...

my problem is that my range of IR is very very short, i would say it is only about 5cm..my IR led is being supplied for 100mA(which is the max)

I am using normal IR transmitter and normal receiver.
As i've read this thread, im quite consufed over what actually does affect the range of the IR beam?
isiit the receiver?transmitter?

I am getting a TSOP1738 soon and i havent try on it yet. will this recevier actually boost my detection range?

I thought of getting a highpower wide beam IR emitter too....my desired range is around 15~20 feets.

 

Both affect it, you can pulse the IR LED at fairly high currents (1A is quite common), and this increases the range. Using the TSOP receivers is good as well, as these are very sensitive and a really easy to use - bear in mind you need to modulate your LED at 38KHz or so, depending on the exact TSOP you use.

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PIC programmer software, and PIC Tutorials at:
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thanks for the speedy reply,
the tsop im using is 38khz.
will it blow the LED at 1A-38khz pulse?or shud i make the hightime short and longer low(0) time so that the LED will not blow?(to maintain at lower duty ratio?)

i am using reflection technique to detect the IR on the receiver, should i go for narrow beam or wide beam IR?whish has better range?and what are the pro and cons?
thanks

 

The datasheet for your IR LED should spec a max pulsed current rating and a minimum duty-cycle for it.

The TSOP receivers have an automatic gain control that reduces the gain during a continuous signal, because it thinks it is interference. Therefore the data must be received in bursts of from 10 to 140 data pulses then a gap time of at least 14 pulses between bursts for its gain to continue at max.

An LED makes a narrow beam by focussing it. Then its intensity is increased and its range will be far. But it might be difficult to point or reflect a very narrow beam that is invisible at the receiver, a beam with a wide angle would be easy but have less range.

__________________
Uncle $crooge

 

Like Audioguru says, you don't run it at 38KHz continually, it's usually coded in some way, and the coding is designed to give plenty of rest time inbetween the 38KHz pulses. Check my IR PIC tutorial for details of the Sony SIRC's system.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

From what compass1982 has posted
http://www.electro-tech-online.com/a...g?d=1162520040
The frequency of the 555 timer is actually 32.9khz (T=30.36us). and it is not anywhere near 38khz.(i used T=0.69(Ra+2Rb)C to calculate).
I did a simulation using multisim with the calculated values from the formula and happens that the simulation result is 20khz and not 38khz.
I am just wondering how to determine the values of Ra, Rb and C when the actual and the calculated is so far apart.
anyone can show me the values that u used to generate a 38khz frequency for TSOP1738?
thanks

 

Are the values of the timing parts too high and too low for a 555, as shown in the circuit posted by compass1982? The resistors are nearly short circuits and the value of the capacitor is far too high. Look at the graph of recommended parts values in the datasheet.

Are the values of your parts 5%? Then the 38kHz could be anywhere from 34.2kHz to 41.8kHz if your numbers were as accurate as the calculation formula in the datasheet.

Is your power supply properly bypassed? A 555 draws current spikes of up to 400mA (!) when its powerful output switches that must come from somewhere.

Multisim doesn't seem to know if it is coming or going and makes many mistakes.

__________________
Uncle $crooge

 

I don't think those resistor values are good.

FWIW, LTSpice simulates it high - 44Khz. I suspect the model breaks down due to the low resistors. taking the resistors to 1K and 1.7K and the C to 10n (10000pf), it simulates a spot on frequency.

 

got it...i will try it out with the recommended values in the datasheet first..
thx...i used a 7805 to regulate the voltage for the 555

 

can you explain the meaning of "Therefore the data must be received in bursts of from 10 to 140 data pulses then a gap time of at least 14 pulses between bursts for its gain to continue at max."? I'm getting confused of it... thanks for any help....

 

The TSOP seres of IR receiver ICs are designed for remote control of TVs and other entertainment products. Data is sent in bursts of IR pulses and the automatic gain control in the receiver IC uses the breaks between bursts to know it is data and is not continuous interference. If it receives continuous pulses then it reduces its gain, thinking that the continuous pulses are interference from a compact fluorescent bulb or other item that continuously pulses IR at 38kHz.

The data burst consists of a start bit, the command code bits (volume up or down, channel number etc) then a device code (TV, DVD player, CD player etc). Then a pause between that burst of pulses before the burst of pulses is repeated again if the button is still held down.

__________________
Uncle $crooge

 

i managed to get my timer to operate at 38khz already........thanks...will try out the TSOP receiver once i get it.
any comments about long range and wide range transmitter?any of it to recommend?My desired is about 20ft of transmission