This project, I'm going to detect infrared LED that can transmitting different frequencies such as 100Hz and 150Hz.(Using OOK) And here is the receiver of circuit that I have. So what are the value of these resistor and capacitor? THANK YOU!!
I think your question should be is this circuit correct?
How is it being powered?
What is OOK?
A frequency of 100Hz to 150Hz is very low for this sort of thing.
On-off keying. f=1/T
I'm using infrared to locate the robot indoor. For example I have 2 infrared transmission A and B.
For transmission A, I using code
digitalWrite(8, HIGH);
delay(10);
digitalWrite(8, LOW);
delay(10);
I try to make it send different frequency so I use f=1/T. T is in milisec. So in this transmission f=1/0.01=100Hz
and transmission B, I using
digitalWrite(4, HIGH);
delay(5);
digitalWrite(4, LOW);
delay(5);
So, f=200Hz
So if this 2 is working. I need the receiver that can detect the infrared and know that which transmitter is detected.
If you have any idea or way that can help me, please tell me.
any recommend circuit or idea will be great
So in this transmission f=1/0.02=50Hz
Fixed that for you.
Will the receiver be able to see only one transmitter at any given time, or can the receiver see both?
It may be better to have tx frequencies that are not simple integer multiples of each other, or different mark-space ratios.
Edit: how about using different frequencies of light, and optical filters?
Receiver can see both of it at the same time.
Edit: how about using different frequencies of light, and optical filters?
Can you explain more about this?
greenduck:
Can you explain more about this?
Red LED, red filter, green LED, green filter, IR LED, IR filter...
This is the circuit that I got, but I didn't know how to do with the value of resistor and capacitor.
I prefer to us infrared because we can not see it by naked eyes
You can get different "colours" of IR LEDs too.
And filters for them.
I didn't know how to do with the value of resistor and capacitor
The circuit is an active bandpass filter and amplifier. You will need to pick components to give the required gain and to match the signal frequency.
There are lots of design tutorials on line. This was the top search result.
What if I need to detect various of frequency in the same time. Is that possible?
You need one bandpass filter for each frequency to be detected.
A bandpass filter can be implemented in software instead of hardware, but you will need a photodiode amplifier in any case.
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You can measure the R's and C's with a DMM.
greenduck:
What if I need to detect various of frequency in the same time. Is that possible?
Of course it's possible. What do you think a radio receiver does?
Any advice? how to do it or any website or video.
See reply #10.
What is the point of posting, if you don't read or follow the advice given in the replies?
If you want to try the digital approach rather than analog frequency filtering, your multiple (identical) IR beacons could emit short digital ‘chirps’ of their payload at random, non-modulo intervals.
The receiver can ignore mixed or corrupted messages, and act upon each valid reception. Worst case, wait for the next chirp which might be a few millis away.
If you want to make it directional, just put an opaque straw over the TX and RX diodes.
There are many variations on the theme, but for many applications this would be very cheap & easy to implement.
Hi,
Do you have any electronic measurement equipment, such as an oscilloscope of some sort and DMM?
What is your electronics, programming, arduino, hardware experience?
How will the signals you receive/detect be able to give you the location of the target?
Can you tell us the principle you are proposing to accomplish this?
Thanks.. Tom.. 