Need to do 30 KHz

A

alexthefox

Senior Member
Hi, im here with a new question.
i check in manual 2, something to do 30 Khz on output ( i need to drive a IR Led), but i cant find nothing.
i whant to use a 18X processor.
Any idea?
i suppose to use PWMOUT istruction but im not sure if its a good solution.
thk
Alex
 
W

Wrenow

Senior Member
If you can give a little more detail as to why you need to drive 3 IR outputs at 30Khz, perhaps other solutions might present themselves. Exactly what are you trying to do?

Cheers,

Wreno
 
hippy

hippy

Technical Support
Staff member
You can connect three IR LED's plus R's with their pointy-ends to Output Pin 3 to three other Output Pins. Only when a related Output Pins are high will the selected IR LED send anything.
 
A

alexthefox

Senior Member
Wrenow said:
If you can give a little more detail as to why you need to drive 3 IR outputs at 30Khz, perhaps other solutions might present themselves. Exactly what are you trying to do?

Cheers,

Wreno
Click to expand...
i whant to do a ir range sensor. with 3 sensor left-center-right position, so maybe i need 3 sensor and 3 led. the sensor work at 30khz, and i suppose o use Infrain of picaxe 08M, but i read it work at 38khz.
 
P

profmason

Member
IR at non 38Khz

There was a thread a few days ago on using IR at non 38Khz. I wrote up the project at:
http://profmason.com/?p=448

Use a pwmout of 30Khz 50% tied to a N2222 transistor to drive the LEDs as shown in the page. If you are trying to send data AND it with a 2400 baud serial out from a different pin.

To do the receiver side use a IR TSOP 30. If you are just looking for signal, feed it into a digital input and it will give you on off. If you are trying to do range finding you can feed the receiver into a analog input. If you want to get serial data have your receiver do a serin pin, 2400, b0. The TSOP will filter out the carrier and just transmit the serial stream.

You will need to shroud things carefully to make it work.

Alternately you should just buy the sharp IR sensors which give an analog out proportional to distance like the sharp GP2D12. While these cost $10 each, they work every time!

I can't believe I don't have a write up on using the GP2D12's! The only thing I can find is an article I wrote on using the QRD1114. This is an integrated IR emitter detector pair useful for line following.
http://profmason.com/?p=213
 
A

alexthefox

Senior Member
profmason said:
There was a thread a few days ago on using IR at non 38Khz. I wrote up the project at:
http://profmason.com/?p=448

Use a pwmout of 30Khz 50% tied to a N2222 transistor to drive the LEDs as shown in the page. If you are trying to send data AND it with a 2400 baud serial out from a different pin.

To do the receiver side use a IR TSOP 30. If you are just looking for signal, feed it into a digital input and it will give you on off. If you are trying to do range finding you can feed the receiver into a analog input. If you want to get serial data have your receiver do a serin pin, 2400, b0. The TSOP will filter out the carrier and just transmit the serial stream.

You will need to shroud things carefully to make it work.

Alternately you should just buy the sharp IR sensors which give an analog out proportional to distance like the sharp GP2D12. While these cost $10 each, they work every time!

I can't believe I don't have a write up on using the GP2D12's! The only thing I can find is an article I wrote on using the QRD1114. This is an integrated IR emitter detector pair useful for line following.
http://profmason.com/?p=213
Click to expand...
the problem of QRD1114 is it range, in the link you have posted there is write it have just 1 cm of range. GP2D12 cost around 24 euros.. 3 led + 3 ir reciver... abour 3 euros. i try to do what you have suggest in the top of your post. thk y to much
 
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