IR ?

Jimi Freeman

Has anyone written or know of a program that can loop through the different frequencies for televisions and power them off like the TV-b-gone product? Where can I learn more about getting started doing this in pbasic?

Mike Green

There's a tutorial on IR and Stamps called "IR Remote for the BoeBot" that you should download and read. You should also read through "What's a Microcontroller?". All the tutorials can be found by going to Parallax's main webpage and clicking on the Resources tab. You'll see a link to Downloads. Click on that and you'll see a link to Stamps in Class Downloads. Click on that and you'll see all the tutorials.

erco

I'm sure there are over a hundred different IR coding formats
to cover every possible·set like the TV-Be-Gone you mention. The big brands (Sony, Sharp) are easy to find on the web, but you'll have your work cut out to find the lesser ones (Advent, Daewoo, etc). Before you decide to make this a project, see this mini IR remote off eBay delivered from Hong Kong for the princely sum of $2.64:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=400021358773
It·scans through all the MUTE combinations automatically when you hold a certain key down. You release it when the TV actually mutes, then you have full control: channel & volume up/down, mute & power.

BTW,· the TV control codes are changing with the·transition to HDTV sets, so this and your TV Be Gone may be less effective·as time goes by. Nonetheless, the·remote is valuable because it is easy to program·to the Sony format, which·makes it compatible·with many BS2 projects.

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·"If you build it, they will come."

erco

I did successfully get a·BS2 to send a single Sony "power" command in this thread:

http://forums.parallax.com/showthread.php?p=759751

The BS2 modulated an external 555 circuit that generated the 38 kHz IR carrier signal.

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·"If you build it, they will come."

Jimi Freeman

I ran the code w/ the IR led, from this http://forums.parallax.com/forums/default.aspx?f=5&m=302686 forum post that you mentioned, but it never turns the TV on or off. I have Pin 15 going to the annode lead over the led w/ a 1K resistor, and 220K transistor going to the cathode lead on the ir, to the vss, but it isnt working. What am I doing wrong? ........ after re-reading your article, apparently I need to build a 555 timer? Not sure what that is, but I dont have potentomitoer... didnt come w/ the boe-bot kit so i will order one

Post Edited (Jimi Freeman) : 1/20/2009 11:48:32 PM GMT

erco

Yes, you need an external 555 circuit that is adjusted to send IR pulses at ~39 kHz. That code I posted switches the 555 circuit on & off. I'll dig up a circuit tonight·from home, but this one should work for you: http://www.reconnsworld.com/ir_ultrasonic_555timer40khzir.html

Just follow the hookup directions commented in the code; 555·pin 4 (reset) to Stamp pin 15·(instead of to·555 pin 8/Vcc as that schematic shows).· And power the Stamp and 555 circuit from the same Ground (Vss) and +5V (Vcc) connections. Don't count on using the Stamp's internal regulator to provide power to the 555 circuit, use an external regulator like a 7805 or equiv. You'll have to use a frequency counter or meter (or a slick BS2 COUNT program) to adjust the 555's pot to output 39 kHz. And for this adjustment, you will want to temporarily make the 555's reset pin 4 high for constant output.

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·"If you build it, they will come."

stephenwagner

Jimi

I have some PBasic programming code and the IR remode codes to·"Power Toggel On Off On Off" a·Magnavox TV·Receiver.

I will post the PBasic code tomorrow.

Still you will need a 555 timer circuit or this product from Rentron http://www.rentron.com/remote_control/TX-IR.htm·to drive the IR LED.

You may also want to view my Parallax customer application IR Repeater project. It receives the RCA Dish "Power Toggel", RCA TV "Volume + & -" and "Mute" IR codes and it transmittes the Magnavox TV "Power Toggel", "Volume + & -" and "Mute" IR codes.
http://www.parallax.com/tabid/321/Default.aspx.

I hope this helps.


SJW

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