Chromebook hack controls your television

chromebook_remote_control1

[Michael Kohn] only accomplished about half of what he set out to, but we still think his TV channel switcher from a Chromebook turned out nicely. When starting the project he wanted to include a grid of listing so that he could choose a specific program, but decided that scraping the data was too much work for this go-round.

The Chromebook doesn’t include an IR transmitter so he built one using an MSP430 chip. He had previously built a little transmitter around an AVR chip and was surprised to find that the internal oscillator on that was quite a bit more accurate than on the MSP430. Timing is everything with the Manchester encoded signals used for IR remote controls so he used his oscilloscope to tune the DCO as accurately as possible.

The app shown on the screen was written in Javascript. Google published some example code on using RS232 with the computer; [Michael] used this resource to provide communications between the computer and the microcontroller.

Comments

  1. That’s pretty cool. Maybe instead of scraping the data from a tv guide online you could embed the tv guide information and include the script to change the channels.

  2. tjbaudio says:

    http://www.schedulesdirect.org/ I have used this for years with Mythtv. you get the data in an XML download.

    • Velli says:

      “Please remember that your membership fee is not a purchase of guide data.”
      That BS just lost me entirely. “We have something you want. You have to pay us $25 to get it, but you’re TOTALLY NOT PURCHASING IT.”

      So then scraping it from someone else is totally not stealing it…

      • tjbaudio says:

        You are licensing the use of the data, not buying the data. Very big difference legally. From an end user stand point you get what you need, you just can’t sell it to others.

        • Velli says:

          Not even licensing it. According to them, the data is entirely incidental to the payment for a membership. But you still can’t get the data without paying them, and they don’t do anything else.

          • Shadow says:

            It gets the job done far easier than anything else currently availible, especially scraping sources that regularly see format changes. If you don’t get caught up in the legalese it’s a very affordable option at around 2 dollars a month for accurate listing data, and they have consistently provided the data for many years now.

            I’ve used it for almost three years now with MediaPortal+XBMC along with a HDhomerun and homemade antenna and I couldn’t be happier.

            This hack would probably be more useful with such a DVR portion, which would also allows streaming to mobile devices with the right additional software. Most USB IR remotes including LEDs for IR blasting based on any input (at least with IRServer), making that part relatively trivial. It is cool to see it done with a microcontroller though.

          • tjbaudio says:

            In short, get over it. SD is working within the limits of the contracts they have with the company that provides the data to them. The wording is not really relivant. You pay $25 a year and get to use the data you want. I was around when SD was formed, and even had a hand with a small part of their policy. The potential alternatives were MUCH worse than what we got. I think what we got is a very good deal.

  3. Nerdy dude says:

    I’m a little disappointed after reading his page and came across this: ” I really wish TI would make an MSP430G in DIP format that can take 16MHz external crystals :(“. I don’t think any of TI’s MSP430s CAN”T take a 16 mHz crystal. Any of their value line series can. See http://www.ti.com/lsds/ti/microcontroller/16-bit_msp430/products.page. Maybe I am missing something.

    • NatureTM says:

      I think most of the value line doesn’t accept a 16MHz crystal directly. Maybe some of the new ones do, but I’m not sure. You can, however, use a low frequency watch crystal and either calibrate the chip permanently for 16MHz operation or set the frequency during runtime using a small library using the crystal as a reference. Many of the bigger value line chips come pre-calibrated, though it still might be necessary to calibrate at runtime for more precise clocks if the chip operates in variable temperatures.

      It’s not too much of a hassle. When I would buy new chips that weren’t 16MHz pre-calibrated, I would just load the calibration program on each of them using a LaunchPad with a watch crystal attached. The settings get stored in flash. In most applications this was accurate enough to then operate without any crystal thereafter, even when doing serial communications.

  4. I’ll just leave this here http://csmatt.com/notes/?p=32 . It’s my go of controlling my HTPC TV (IR and input over wifi using Unified Remote)

  5. James Arnett says:

    This is awesome. They should really think about unifying there devices. Google TV’s being controlled by any google device that is on the same wifi network i.e. chromebook, android phone, android tablet. iOS is doing it why cant we?

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