Searching \ for '[PIC]: A bit more on"How to implement a Infrared' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'A bit more on"How to implement a Infrared'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: A bit more on"How to implement a Infrared'
2002\06\30@234311 by Jinx

face picon face
> The devices that will communicate, will nearly be in contact with each
> other, and there will be no external light interference at all

In that case you should be able to use an IR diode as the receiver
rather than the more expensive receiver+filter+amp type. You just
need to give the diode a little bias via a resistor to Vcc. If you have
any small transistors in a TO18 metal can you can cut the top off
and make your own opto-transistor with the IR shining straight on
to the base in the silicon. If the IR is strong enough you might not
need any signal amplification for the PIC to get the data cleanly

--
http://www.piclist.com hint: To leave the PICList
spam_OUTpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu



'[PIC]: A bit more on"How to implement a Infrared'
2002\07\01@003153 by hard Prosser
flavicon
face
An alternative may be to remove the sensors from an old mouse - if
neccessary cutting them into separate tx & rx parts. Although often they
are already separate components.
They are desined to work together so the wavelengths should match & are set
up to operate over a few mm of separation.

Richard P



> The devices that will communicate, will nearly be in contact with each
> other, and there will be no external light interference at all

In that case you should be able to use an IR diode as the receiver
rather than the more expensive receiver+filter+amp type. You just
need to give the diode a little bias via a resistor to Vcc. If you have
any small transistors in a TO18 metal can you can cut the top off
and make your own opto-transistor with the IR shining straight on
to the base in the silicon. If the IR is strong enough you might not
need any signal amplification for the PIC to get the data cleanly

--
http://www.piclist.com hint: To leave the PICList
.....piclist-unsubscribe-requestKILLspamspam@spam@mitvma.mit.edu

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@004445 by Jinx

face picon face
> could perhaps just use a pullup resistor with your receiver.  If you
> cannot get a clean signal this way you must build a more elaborate
> circuit to successfully detect the IR signal.  I do not have any
> examples of this I am afraid, but it is a common enough project to find

I have some circuits based on FET input and transistor amp output
if you get stuck. I don't use them myself but they do work and would
be OK for short range comms

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@010138 by Gabriel Caffese

flavicon
face
       Yes, I can´t go on.
       It would be of great help if you send me those diagrams.

       Thanks again to everyone.

                       Gabriel.-



-----Mensaje original-----
De: pic microcontroller discussion list
[PICLISTspamKILLspamMITVMA.MIT.EDU]En nombre de Jinx
Enviado el: Lunes, 01 de Julio de 2002 01:47
Para: .....PICLISTKILLspamspam.....MITVMA.MIT.EDU
Asunto: Re: [PIC]: A bit more on"How to implement a Infrared
communications"


> could perhaps just use a pullup resistor with your receiver.  If you
> cannot get a clean signal this way you must build a more elaborate
> circuit to successfully detect the IR signal.  I do not have any
> examples of this I am afraid, but it is a common enough project to find

I have some circuits based on FET input and transistor amp output
if you get stuck. I don't use them myself but they do work and would
be OK for short range comms

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@010958 by Tan Chun Chiek
flavicon
face
Sorry, but going a bit OT

is it possible to demodulate a 38khz signal to get data using discretes and
logics?

Thanks,
Tan CC

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@043911 by uter van ooijen & floortje hanneman

picon face
> is it possible to demodulate a 38khz signal to get data using discretes
and
> logics?

Of course, in the same way that you can write your own C compiler :)

Wouter van Ooijen
--
Van Ooijen Technische Informatica: http://www.voti.nl
Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@050027 by Russell McMahon

face
flavicon
face
> is it possible to demodulate a 38khz signal to get data using discretes
and
> logics?


Yes.
But it is very unlikely to be worthwhile unless you mainly value the
learning experience or have an extremely demanding requirement (and even
then it may not be).

For about $US2 retail you can buy a 3 chip device that has an optical filter
(piece of coloured plastic), amplifier, bandpass filter  and
detector/demodulator plus associated gain control circuitry. To reproduce
this yourself with equal results would take a handful of transistors or
several op-amps and associated components in each case. The size would be
much larger and achieving performance similar to the $2 part would not be
trivial.


       Russell McMahon

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@081411 by Olin Lathrop

face picon face
> is it possible to demodulate a 38khz signal to get data using discretes
and
> logics?

Of course, preferably done with vacuum tubes.  You can also grow your own
wheat and bake and slice your own bread.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@100513 by Russell McMahon

face
flavicon
face
> > is it possible to demodulate a 38khz signal to get data using discretes
> and
> > logics?
>
> Of course, preferably done with vacuum tubes.  You can also grow your own
> wheat and bake and slice your own bread.

Olin is of course right - you can. Just as some people do prefer to bake
their own bread and / or grow their own wheat even though easier
alternatives exist. Apart from the sense of satisfaction gained there can be
other benefits. Leaving aside the benefits of home grown wheat, as Jinx
notes, there can be reasons to "roll your own". Low power consumption would
be one such reason - a homebuilt detector could be designed to operate in a
sampling mode with the electronics powered down for most of the time. I see
no reason why the 3 mA or so typical idle current could not be reduced to
100 uA or less. The signals sent may need to be adapted to suit the
potential for loss of data at the start of a data burst. Other possible
reasons might be very high or very low bandwidth or high sensitivity or
..... . Or perhaps the pleasure some feel when they see the valve filaments
light up :-).


       RM

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@145055 by Peter L. Peres

picon face
On Tue, 2 Jul 2002, Russell McMahon wrote:

{Quote hidden}

I always thought the real preasure comes from lighting the *anodes* ? ;-)

Peter

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@145100 by Peter L. Peres

picon face
On Sun, 30 Jun 2002, wouter van ooijen & floortje hanneman wrote:

>> is it possible to demodulate a 38khz signal to get data using discretes
>and
>> logics?
>
>Of course, in the same way that you can write your own C compiler :)

Almost ;-). Writing C compilers (that work) is a full time job imho.

Peter

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@145109 by Peter L. Peres

picon face
On Mon, 1 Jul 2002, Tan Chun Chiek wrote:

>Sorry, but going a bit OT
>
>is it possible to demodulate a 38khz signal to get data using discretes and
>logics?

Yes but you need to be good about analog electronics. One high sensitivity
receiver I built used a 38kHz tank circuit at the input, one low noise
buffer stage, then a single transistor mixer and a 455kHz IF strip as
amplifier. The LO was 480kHz ceramic resonator. You don't need such
sensitive devices. This was for optical beam (free air) voice and data
link.

Peter

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\01@160400 by uter van ooijen & floortje hanneman

picon face
> >Of course, in the same way that you can write your own C compiler :)

> Almost ;-). Writing C compilers (that work) is a full time job imho.

I guess that depends on your background: I wrote the Jal compiler for fun (I
admit: it is not a C compiler), but I would not think of designing an IR
reciever to match the preformance of a $2 TSOP, SFH or the like.

Wouter van Ooijen
--
Van Ooijen Technische Informatica: http://www.voti.nl
Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...