Cutting The Cable

You may have inferred the fact that I have recently upgraded a perfectly wonderful MacBook Air to the latest model. And you may also know that I've been geeking with the Raspberry Pi. Implicit in this is my desire to create the perfect Internet/TV lash-up. If you buy an Internet-ready TV, you'll find it has some of the apps you want, but it'll have some annoying gaps that are filled by the Apple TV. And if you buy an Apple TV set top box, you'll find it has more of the apps you want, but other annoying gaps that are filled by the Raspberry Pi. (If you think this is an unreasonable line of reasoning, I agree and I blame my friend Paul.) My days of subscribing to Cable TV are numbered.

So, I've been poking around figuring things out how to plug those gaps.

Since the weather has gotten cold, I don't like to walk outside with my wife for exercise. We have a treadmill and Nordic Trak next to one another, but took out the TV in front of them when television went HD digital a while back. So, I didn't want to be cold when I exercise. and I didn't want to be bored, either. So, this morning after breakfast, I trotted off to Best Buy and bought an open-box Samsung TV. It's not particularly large, and it was reasonably priced. So reasonably priced that I was able to throw in another Apple TV into the deal.

It took a few hours and a bit of to-and-fro with the cables, but I got both the Apple TV and the Raspberry Pi XBMC application going. If you're going to do this, I recommend a TV that implements some form of HDMI/CEC so you don't have to fuss with adding a keyboard, mouse, or other interface to the Raspberry Pi.

Because I got the television dirt cheap, it did not have HDMI/CEC. But I was able to dispense with the keyboard/mouse after I told the XBMC application to let other programs control it over the net. After I turned that on, I was able to download and configure apps for my Android phone and also for my iPad so that each can serve as a remote control That's pretty cool to pick up the cell phone or the iPad when you want to pause a video.

(I got my wife a Nest thermostat for Christmas. So, this morning I turned up the temperature without getting out of bed with my iPad. I love living in the future.)

I made mention of upgrading a perfectly good MacBook Air, because it supports this feature called "AirPlay mirroring." Thus, when I'm running the MacBook Air, I can mirror its display to the television. Anything I can see on my Mac I can also see on my TV without having to schlep a bunch of cables between things. And all the wires are tucked behind the television and its stand the way God intended them to.

In these days of HDTV, I find that I can dispense with a lot of complexity I had to sort out in the 1990s, but I get a lot of new complexity. So, it's a wash. It's amazing how much awesome technology you can get for not much money these days.

With a HDTV, Apple TV, and Raspberry Pi running XBMC, I figure I can have the almost-perfect television-viewing experience...

WHEN I SHOULD BE READING A BOOK.

The Magic Raspberry

I got my Raspberry Pi put into an enclosure and doing great things running XBMC with my TV. I wasn't thinking and I picked up the TV Remote Control instead of the micro wireless keyboard. Instead of pushing the arrow buttons on the keyboard, I pushed the arrow buttons on the remote control.

It did what I wanted.

Then I stopped. Oh my gosh. How did that do that? That shouldn't have worked.

I'm an engineer. I understand things. If you push a button on a remote control, infrared light waves go speeding to an eye built into the TV. The Raspberry Pi has no eyes. It is blind to infrared light and everything else. It CAN'T respond to the remote!

Your eye does not work in the infrared. So, when you push the button on the remote control, you don't see anything.  Your smartphone's camera uses a sensor that is sensitive to infrared. So, when you aim a remote at it, you can tell whether it's emitting or not.
(If you're a terrorist worried about infrared targeting lasers from the US military, you already know this. I said I understand things.)

My wife held the remote up to the camera with the button off and the button pushed on so that we could illustrate this.

How in the world did my Raspberry Pi figure out that I'd pushed the button on the TV remote?

After a bit of Googling, I found the HDMI standard and read about a CEC (Consumer Electronics Control) connection. If you have the right kind of HDTV, it can send commands back down the HDMI cable from the TV. And if the thang, Blu-Ray player, cable box, satellite box, whatever, is smart enough, it'll respond to those commands. It's like freaking magic.

This has profound ramifications for use of a Raspberry Pi as a set top computer. You don't need to hook ANY MOUSE or KEYBOARD to it: Just power, HDMI, and Ethernet. No USB hub or even those cute little wireless dongles.

So, I got to thinking, let's try this on my other TV set. I did. No joy. HDMI CEC is not on every TV set, just a select few. Since Black Friday is coming up, you might want to know what to look for if you're going to be buying a TV.

According to Wikipedia, the Trade names for CEC are

• Anynet+ (Samsung); 
• Aquos Link (Sharp); 
• BRAVIA Link and BRAVIA Sync (Sony); 
• HDMI-CEC (Hitachi); 
• E-link (AOC); 
• Kuro Link (Pioneer); 
• CE-Link and Regza Link (Toshiba); 
• RIHD (Remote Interactive over HDMI) (Onkyo); 
• RuncoLink (Runco International); 
• SimpLink (LG); 
• HDAVI Control, EZ-Sync, VIERA Link (Panasonic); 
• EasyLink (Philips); and 
• NetCommand for HDMI (Mitsubishi).

Before you buy a TV from these vendors, look in the specs for these buzz-words. If you see them on the set you want to buy, you'll know its TV remote can control your Raspberry Pi XBMC application.