IR emitter detector

[hasanaziz008]

hi
i am making a line tracking robot and i am using an infrared emitter and detector i read it some where that if i make the emitter ocillat at 440MHz i can avoid all noise or problems caused by visible light
now the problem is that i dont know what to do with the dector should i simply place i or do i have to add some circuitry wih it to detect the signal at 440MHz please help

 

[falleafd]

To transmit, perhaps you can make it by hardware solutions, but how can you recognize if with a microcontroller? the max of microcontroller is only about tens of MHz. And if you want to build it, you only can use external hardware.

However, taking into account that using complex hardware with protecting your sensors by covering it, and sending/reading it with a small MC. What will you choose? They usually use IR at 40KHz, it's enough, and it works good, quite good, and very good.

 

[hasanaziz008]

ok i will make it 40KHz and didnt get what u said about detecting it with a micro controller can u be more specific

 

[falleafd]

There are 2 ways to generate the pulse on IR transceiver to creat 40KHz.

1) you can generate it by hardware, you can make it using 555 for example

2) You can use software to generate it with microcontrollers. I like this way.

Note that some compact transceiver are preset from 30 KHz to 50KHz, but as you build your own sensors with IR led and receiver, you can do 1 of those methods.

 

[Nigel Goodwin]

ok i will make it 40KHz and didnt get what u said about detecting it with a micro controller can u be more specific

Have a look at my tutorials, I use a PIC to generate the 40KHz signal, and TV remote control receiver IC's to receive it.

 

[falleafd]

Nigel,

If you don't mind, I have some ideas about your tutorial that

1) May you give more clear and simple routines for beginners only? For example, you write it as timer tutorial, adc tutorial, pwm tutorial.... and it should be very simple to understand. Because, at the first time as I learn to write PIC, I cannot read your tutorial.

2) Do you work on motion control? Have you done a tutorial for PID control with PIC 16f876? And some other project such as fuzzy control... Yup, we can found those application notes on microchip site, but i think they are not popular, because people usually use mid range pic more than high end. And they did it with C codes. A mpasm tutorial on these project should be helpful for beginners.

3) If you don't mind, you can tell techniciens on this forum to give you their hands. And I think you tutorial is very very good. If it has more project, it will soon becomes perfect.

 

[ivancho]

You can pulse a IR led with a 555 at 38KHz (way more simple wasting computing power of a microcontroller) and have a IR detector that detects only that frecuency, say **broken link removed**. The detector will pull low if a signal is present, and will be floating if no IR detection (open collector output)

Good Luck

Ivancho

 

[hasanaziz008]

thanks

thaks it was alot of help