Step 4: Hacking the Remote

I bought a big old GE component video monitor at an auction about 10 years ago.  Earlier this year I finally found a use for the monitor, but lo and behold when I hooked it up the thing was dead.  The good news is that the monitor came with this awesome remote control!

Measuring the IR Signals:
To understand the remote control I hooked up my IR detector to a storage oscilloscope and started pressing buttons.  The nice thing about a storage scope is that it saves the IR code on the screen for you to analyze.  Taking it a step further, I actually saved the traces for each button as a .CSV file to import into an Excel or OpenOffice Calc Spreadsheet.  See the attached file for my IR signal spreadsheet for the Power button.

Analyzing the IR Signals:
To use the remote, I wasn't necessarily interested in decoding the whole message structure.  Mainly, I wanted to find the differences in the signal for each button press.

Using the spreadsheet and the time-stamped scope data, I discovered each IR signal had three parts - a start pulse, a 16-bit Remote ID (which is the same for all buttons), and then a 16-bit Button Code which is unique for each button.  By looking at the last 16-bits of the IR signal, we are able to discern which button was pressed.

The one tricky part to using the remote code is when you hold down any button, the remote sends out an identical "repeat code" until the button is released.  This repeat code is very similar to the start pulse, but with different time durations.

Using the IR Signals:
I have the IR signal connected to the PIC Interrupt-On-Change pin.  Using the internal Timer 0 module, we can count the time period between falling edges on this pin.  Everytime there is a falling edge, the PIC saves the state of the TMR0 register (to record the previous period) and then restarts TMR0 (to record the next period).  Using this information, we can determine whether a 1, 0, Start pulse, or Repeat pulse was received.

<p>Very clever. Can you tell me how to replace the remote contol with a timer that will very slowly change the color. when I say very slowly I mean over periods of days. I am building a Little Free Library for my neighborhood the frount door of which is plexiglass engraved with the Door of Moria back lit by 12v LED strip. I would like for it to occasionally &quot;magically&quot; change color. My knowledge of electronics is very limited so any help you could give me would be greatly appreciated. </p>
<p>Hi, thanks for looking! The easiest way to do what you want might be to purchase a pre-built RGB controller, like this: </p><p><a href="https://www.adafruit.com/products/678" rel="nofollow">https://www.adafruit.com/products/678</a></p><p>I see this one offers speed and brightness control, but you'll want to check with them to see whether the slow speed will actually get you down to the &quot;days&quot; timeframe. Sounds like a cool idea - Good luck!</p>
Excellent instructable! I'm thinking about building something similar. Quick questions before I jump into getting the parts together: are you able to properly illuminate your room with this setup or is it more of an ambient light? How big is your room? How's the colour temperature on full brightness? Is it very &quot;sterile&quot; or can you produce comfortable lighting for, say, a living room?<br>Thanks, Tobias
<p>Hi, Thanks for looking! To answer your question - the light from my lamp is pretty &quot;sterile&quot;, although I didn't spend a lot of time trying to optimize for color temperature. I use this daily in a 14x16 ft. bedroom for getting dressed, etc and it works well. When it comes to reading, though, I prefer a desk lamp. I think it could work for a living room with more time/care spent on tweaking the color temperature more LEDs or better positioning. You can also use two sets of LEDs - buy some nice &quot;Warm&quot; ones for white-light mode, and use cheap RGB oness for different colors.</p>
Thanks for your quick reply. Actually I don't really need RGB LEDs so white only is a good idea.<br>Again, thank you.<br>Tobias
Nice instructable, gonna try this one out. I get how the power supply works for the led's but how to you power the ic circuit?
Hey, thanks for the comment! You're right, I distinctly left out details of how to power the logic... I went back and updated the schematic and instructable just now. I used the +30V power supply to power the LEDs, and for the logic +5V I used an LM7805 linear voltage regulator with a 12V zener diode (reverse biased) in series with the input. The zener knocks the 30V down to 18V for the input to the LM7805, which makes the regulator happier. Good luck, and have fun!
this is so cool ! must have video please !!
Hello, thanks for the comment! I have a video up on youtube, you can check it out here: http://www.youtube.com/watch?v=BINE3xcdq_M <br>
thanks ajax =)
Definitely this serves as great inspiration :) Nice job!
This looks like a great add-on to a tv. Is there an interface for tv signal to change the mood lighting?
After rearranging the code, you could make it respond to any type of IR signal... It would be cool to have a &quot;secret&quot; button on your TV remote that puts it in mood lighting mode.
If am not wrong one can cut own the budget. <br>One uses LED strips (multicolor) : Rs.100 /meter <br>IR Remote + its receiver : Rs. 250 <br>LED Strip Driver : Rs.250 <br> <br>Total Rs. 600 (padding amount to Rs.400) total Rs.1000 <br> <br>We can Get these Lighting Except the frame for $20 MAX isnt it ?
very good
Absolutely beautiful light. Sure is complicated, but you explained it very well. <br>Awesome skill!
Couldn't we just buy RGB LED strips for the underside of cars, hook up a power adapter? Also are you sure cardboard is a wise choice? I suppose if the LED's don't produce a lot of heat (some do) it would be alright.
Hi TXTCLA55, I wanted to make sure I had enough light output to make this a functional ceiling light, so that's why I went for the super high brightness LEDs. I have never used the automotive LED strips, so I can't really say how well they'd work... <br /> <br />Corrugated cardboard actually did work well because it is fairly rigid and also very lightweight. To reduce heat concerns, the LEDs were each mounted on to heatsinks and elevated above the cardboard on plastic spacers to allow for airflow (see pics in Step 6).
How much did this cost for all the parts?
The most expensive parts are the LEDs ($6/ea on Ebay) and the power supply ($32). Everything else is pretty inexpensive or free depending on how hard you look. <br /> <br />I'm guessing in total you'd be looking at around $100-$125, not including the remote. (There is one of these GE remotes on Ebay right now, but it is priced at $84. That seems a little steep...)
Great job!! what kind of power supply did you use? how much current can it supply?
Hey, thanks. <br /> <br />I ended buying a power supply from Mouser (www.mouser.com). It is: <br />30V, 2A, 60W <br />Part# 418-CFM60S300 <br />Price: $34.25 <br />(Instructable edited with this info) <br /> <br />Most of the supplies out there are 28V or 32V, but this one was right in the middle. Plus, it was very lightweight. <br /> <br />
The results look great!
This is a pretty sweet project! Can you get the led's to change to any color in the spectrum, or can the micro controller only handle primary's?
I think says right here in Step 1, Either it's white, or fading through the colours, and can be paused at anytime. <br /> <br />I would love to do this, great one! But, Im not sure if I know enough about micro controllers and circuits to attempt such a project yet <br /> <br />
i just wasn't sure if just faded through the primary's or if it had all the colors along the way. The reason i ask is i know it takes considerably more work to make it fade smoothly through all the colors.
Thanks for the comments, guys!<br /> <br /> The lamp is <em>capable </em>of individual 10-bit brightness control for each color, so it can potentially produce millions of colors. <em>Currently, though</em>, the lamp color fade routine uses only 2 out of the three primary colors at any given time (see &quot;PWM Control&quot; section of step 5).&nbsp;<br /> <br /> nerd1701 - you got me to thinking... I could potentially add another 10-bit counter to the code that will cycle the third color through the full 10-bit brightness scale. This would unleash the full potential of individual 10-bit RGB brightness control. &nbsp;I might just do that... I'll be sure to update the instructable if I do!<br />
BTW - Since a picture is worth a thousand words, how many words is a video worth?<br /> <br /> This should do a good job explaining the current color fade routine:<br /> <a href="http://www.youtube.com/watch?v=BINE3xcdq_M" rel="nofollow">http://www.youtube.com/watch?v=BINE3xcdq_M</a><br /> <br /> <br />

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