The TV-B-Gone flashlight build

Love to see pictures. Turning a attiny85 into j leads is a good idea. :bigsmile:

Since everything is free shipping on dx it helps to buy each item in a separate order, annoying for a bunch of items but that way one delayed item doesn’t hold up others.

I actually did the J-lead thing in my day job - there was a shortage of SPI flash a few years back, and we found ourselves unable to buy a 16Mbit flash in a narrow SOIC. We ended up J-leading wide SOICs and hand-soldering them on a couple hundred boards.

Well, the original idea was conceived when a bunch of us were at a local "sports themed" restaurant. The table next to us had a few hooligans who were watching soccer on TV and cheering whenever anything would happen, being obnoxiously loud, being inappropriate with the waitress and generally being inconsiderate jackasses. I thought "man, I wish I had a remote for that TV - I'd turn it off right before something interesting happens." So I did some digging, and found the TV-B-Gone project had been done - and was open source!

I haven't found myself in the same situation since I built my pocket one. But I will admit using it a few times - mostly turning off 'decorative' TVs in storefronts, and a few TVs scattered through department stores with product ads on loop.

edit: But yes, I'll confess that this build is the result of boredom :)

Starting to come together - only part I’m missing right now is teflon wire.

I did order PCBs to mount the IR LED on, but these IR LEDs are quite tall and with the LED sitting on top of the PCB, the P60 reflector wouldn’t screw together. So I decided to solder the LED directly to the pill - I tinned the LED and pill, got the pill hot (the solder blob sticking off from the LED is where I had my iron placed to heat the pill) and placed the LED with tweezers. Result:

The Kapton tape is there for insulation for the wires, I’ll cut a few more pieces and cram them in there. I’ll probably pot everything when I’m done to make sure nothing moves.

Installed the Tiny85V microcontroller in place of the Tiny13A. There was plenty of pad available so I bent the leads straight down instead of J-leading, this makes attaching programming clips easier.

And the ceramic resonator’s added to the bottom, to make the AVR frequency more accurate. This is a 4MHz, 4.5mm resonator with built-in capacitors, the center lead (piece of a resistor lead) going to the ground ring is for those capacitors, and the outer leads attach pretty much perfectly to the stars.

Star #2 will be used for NA/EU mode selection. Leaving this star alone makes the flashlight transmit North American TV turn-off codes, connecting it to the ground ring or the first star makes the flashlight transmit EU codes.

I’m currently proofing the software on my AVR Dragon, once I’m happy with it there I’ll slap the light together and cross my fingers.

Nice work.

Update:

Software’s 100% done/tested on my AVR Dragon. Using an ordinary through-hole IR LED, it’s happily turning off my living room TV.

So I put the flashlight together, and it turns out the LED’s cathode is connected to the heatsink pad on the bottom… probably should have made sure first that it was isolated. End result was a direct driven LED with a 1.3V forward voltage. LED’s blown.

I have PCBs I can mount the LED on, but the LED+PCB combo is too thick for the pill/reflector to thread together. I’m starting to think that P60 wasn’t the ideal form factor for this project.

Use just one layer kapton as insulating.
Or use thermal compound glue this insulate too.
I have often seen that some guys glue the LED with a small amount of thermal glue on a piece of hampackage or with similiar clean smooth surface. After that it is totally covered with non insulating material…

I had a p60 p7 dropin and there was the Pill than kapton than big drop of thermal grease…

Have you spare LEDs or do you have to wait 5 weeks for another package?

I’ve got two spare LEDs. Bought the parts to build 3 of these things, knowing full well I’d mess one up somehow :slight_smile:

I’ll probably do the kapton thing. The LED doesn’t dissipate that much power - it’s getting driven by 2.8A at about 1.3V, and the duty cycle’s only about 20% outputting codes. So less than a watt of dissipation.

Once I get this design tested/perfected, I might try and find a LED star capable of holding an Osram SFH4725S. More expensive but the IR output power is about the same, and it’s in a better package for flashlights than the 5 chinawatt DX special.

I wonder if the arrival/departure screens at air ports work on remotes.

That could cause a lot of problems.

Alright Tyler Durden…don’t give TSA any reason to target us :stuck_out_tongue:

Not the intended use of this thing, and hopefully they’ve thought of that.

Most recent TV I turned off was in a department store, playing an “eggies” ad.

GMarsh - Don’t spend your spare time hanging with the Giz Giz crew do you? :wink:

Action shot! The video looks purple because I’m using a camera with the IR filter yanked.

I decided to omit the kapton tape and just glue the IR emitter directly to the pill with Arctic Alumina. I used a thick layer and managed to keep the base isolated. I’m cleaning up the AVR code now to share it.

Nice work, so is there any visible light at all when it is on? It seems like I would accidentally leave it on all the time...

Adding a constant mode for saturating IR motion detectors could also be fun…

When TV codes are finished sending, the microcontroller powers down and current draw is about 250uA. You’re safe for a while if you leave it on.

The flashlight ‘chirps’ very quietly when it’s sending codes - if you hold it up to your ear and click the switch, you can tell whether you turned it on or off by listening for it. Or you can check it by looking at the light with a cellphone camera.

This is cool.

It won’t affect them in any way. Motion detectors work on a much longer wavelength/different principle.

Passive IR motion detectors primarily see at much higher wavelengths, over 5µm (5000nm). Other wavelengths are cut out by a filter window but perhaps enough can still get through. Some datasheet show 0% below 4µm but I’ve also read a report of a high power IR 940nm illuminator reducing the sensitivity of a PIR detector.
Always worth a shot.

gmarsh, I like this (and not for anything malicious or illegal!)

Any thought given to selling a finished dropin for P60s? Or is there so much hand-assembly and fiddling that you couldn’t make it at a decent price point?

Materials used to make the P60 pill:

- Nanjg 105C ($3.50 at DX)

- P60 pill/reflector set ($2.20 at DX)

- DX “5 watt” 940nm IR LED ($6.03 at DX)

- Microcontroller/ceramic resonator ($2.37 + $0.44 + 15% tax)

  • Solder/wire/Arctic Alumina/etc, say $2 worth

Or about 17 bucks. There wasn’t much work involved, probably 1/2 hour total, to finish the construction of one so I’ll say I’ll sell one for about 30 bucks. I ordered the bits to build 3 - I blew 1 led, I’ll keep 1 myself and I’ll sell one.

I’m now looking at a different LED (Osram SFH4725S) which is better than the 5W LED in pretty much every imaginable way except continuous current handling. If I actually make a “sell a few of these to people” product for people, I’ll go with that LED - just need to find a 16mm MCPCB for it.