Old setup (top) transferred to new baffle (bottom)

Extending the life of an old TV

Paula and I bought our first flat panel HDTV back in 2005. The 32″ Samsung was initially installed in our San Jose kitchen before making the trip to Dublin, Ireland and the finally to out home in Bellevue. Back in early 2011 we started noticing some weird artifacts on the screen, it looked like the TV was switching all the images to 8-bit color.

TiVo screen showing compression error
Do you like the left or right better?

It’s not the biggest TV at 32″ and it’s only 720p, but it fits perfectly in our bookshelf so I decided I’d try to fix it. I’m no electrical engineer, but I have a screw driver and an inquisitive spirit. What else would I need… other than a night in a Holiday Inn Express?

I started trying to debug it and pretty quickly came to the conclusion it was a heat issue. My first guess was dust had built up on a heat sink somewhere inside the set. I couldn’t see anything obvious through the vents in the top or bottom, but I tried a few blasts of compressed air to see if it changed anything. It didn’t. If I couldn’t clean it from the outside I’d clean it from the inside, so I opened up the TV. I learned something that is probably obvious to most: opening up a television is a lot like popping the hood on a broken car… it’s satisfying but also pointless act for 99% of the population (and I’m certainly not in the 1%).

What did I find when I opened up the TV? What I didn’t find was dirt. Sure, it was a little dusty, but nothing that looked like it would be choking the life out of our TV. I was, however still convinced the issue was cooling I decided to try increasing the airflow. My plan was simple, slap some small PC case fans on the top of the TV and block off the rest of the top vents to make sure air was pulled from the bottom and not just flowing in from around the fans.

Armed with a sheet of black polypropylene from TAP Plastics and a set of four 50mm case fans I went to work on my TV. I carved up the plastic, screwed the fans in place then duct taped the whole thing to the top of the TV. My improvised fan and baffle worked (almost) perfectly, the TV can now run as long as we like without the picture going all wonky on us.

I say it was “almost” perfect because it was a prototype… the plastic was too thin and the duct tape wasn’t a great hold and had to be redone every couple months. It was, however, good enough that it was on the back of the TV keeping it going for the past three years.

Comparison picture of thin polypropylene to thicker acrylic.
New baffle will be much more rigid

The solution was great in concept but lacking in execution. It was high time to turn the prototype into a finished product so I headed back to TAP plastics and picked up a piece of scrap acrylic for the bargain price of $0. Because I already had a great template in the form of the prototype it was quick to transfer to the new plastic stock.

The finished product is solidly built and screwed directly to the TV (no more slipping!). It actually has way more attention to detail than a hidden hack has any right to be. I suppose I’ll just have to spend more time looking at the back of our TV.

Fans mounted on TV

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Labor day jam session 2014

Our annual tradition of making jam on Labor Day continued in style, with a total of 30 jars of jam in 4 different flavors. In previous years we made jam based primarily on the blackberries we harvested from the walking trail near our house. This year, however, we branched out and made three other varieties using some store-bought fruit too.

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This year’s jam varieties were blackberry/blueberry, strawberry/lemon, raspberry lemon-thyme and Hatch pepper jelly (which is delicious on brie, yum).

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All are delicious, but my favorite is the raspberry lemon-thyme, a recipe we found on the extraordinarily beautiful blog Jules Food… (warning, do not go there when hungry as you are likely to damage your keyboard by drooling all over it).

Here are the recipes we used this year:

Next up, we have a big bag of blueberries just waiting to be turned into blueberry lemon basil jam.

Getting a random string from MySQL for Arduino

When I modded Thomas Taylor’s Tweeting Dryer project to add a washing machine I also wanted to change the way the phrases used by the washer and dryer were implemented. In the original project the strings were hardcoded as a set of global variables. To add a new phrase to the washer or dryer the code needed to be changed in three places then uploaded to the Arduino. I didn’t want to recompile for a string change, so I decided to make my tweeting machines pull their random tweets from a MySQL database on the web.

A usb plug with a forbidden sign

Note: for details and code see my earlier post: Tweeting washer and dryer for Arduino with Ethernet.

Below is a snippet of the code before my change.

#define NUM_MSGS 2 // change this
prog_char msg_0[] PROGMEM = "Hey, I can't fold these things by myself.";
prog_char msg_1[] PROGMEM = "Come and get me while I'm all warm.";
// add a line here
PROGMEM const char* messages[] =
{
msg_0,
msg_1
// Add a line here
};

To add a new string you need to 1) update the #define to reflect the new message count 2) add the string as a new prog_char 3) add to the messages array. Just doing that much work to add a single string is irritating… and you still need to plug your Arduino into your PC to upload your changes (and I bet your development machine isn’t in the laundry room).

Moving the strings from code to MySQL was accomplished with a new function: strFromMySQL. The new function takes a string as input (“washer” or “dryer” in my case) and returns a random quote as a string. The function calls a PHP file which in turn requests a single, random row from a database of quotes. When the string is passed back to the Arduino by the PHP pages the Arduino uses the text finder library to parse the random quote string from the HTTP response.

Setup requires three things:

  1. Create one or more MySQL databases to host your quotes
  2. Modify and upload the PHP files
  3. Update the code with your server name and any needed changes to the path

The database schema is simple, you need tables for washer and dryer quotes and each of those tables need a column to hold the text. To use the code with minimal modifications create two tables, “Dryer” and “Washer”. In each table create a tinytext column named “thequote”. Fill in a few rows of data, using the strings from the original dryer code is a great place to start.

Once you’ve created your database download and modify the PHP files: strFromMySQL. You’ll need to update the conec.php file, adding the information for your MySQL database created in step 1. At this time you can also take a quick look into the washer and dryer PHP files to see what’s going on. The magic here is really not that magical at all, it’s just sorting the database in a random order and limiting the results to a single row.

select * from Washer order by rand() limit 1

Once you’ve uploaded the PHP files to your server it’s a good time to do a quick sanity test to make sure things are working correctly. Open up a web browser and open either your washer or dryer PHP page from the server. If all is working correctly you should see a blank page in your browser. It’s blank because the PHP is designed to return a minimal result so the Arduino has less work. The next step to testing is to right click in the page and view the source (e.g. “view page source” in Chrome or “view source” in IE). When you view the source you should see a quote in angle brackets (e.g. “<Hey, I can’t fold these things by myself.>”). If you don’t see a quote, circle back and check your settings in conec.php and check your MySQL settings. Also make sure PHP is correctly configured on your host and can successfully talk to MySQL.

Now that the PHP pages uploaded and talking to MySQL it’s time to customize the Arduino code.

  1. Turn the on pulling string from the web: set WEBMSG to true (1) on line 6
  2. Add the host name of your string server (the PHP pages, not the MySQL db): update stringServer on line 106
  3. Update strFromMySQL to use the path to your PHP files: change the YOUR_PATH_HERE string to match what is between your host name and, for example, washer.php (line 640). If the URL for your washer.php file is  http://example.com/arduino/strings/washer.php then line 640 should be:
    client.println(“GET /arduino/strings/”+ theDevice+”.php HTTP/1.1″);

You should be ready to go at this point. Recompile the code and upload to your Arduino.

With the strings and the code separated you are now free to add new tweets to your washer and dryer without coding and without fear of running out of memory. Any time you want to add a new string, just go to your database and add a new row, the new string is instantly added into the random queue.

How did this work out for you? Do you have any clever new tweets for a washer or dryer? Share your results in the comments below.

Tweeting dryer, now with washer too

Hallelujah! Today I finally finished adding washer monitoring functionality to the tweeting dryer setup I built earlier (see: Getting started with Arduino). Say hello to Gus!

A picture of a washing machine

My implementation was built up from the excellent work by Thomas Taylor for his article in Make, The Dryer Messenger. It provided a great starting point for this project but I wanted a bit more… I wanted to have my washer tweet and I wanted the washer/dryer quotes to be pulled from the web. Should be simple enough, right? I was thinking that after I added an additional connection to the hardware configuration that it should be as easy as duplicating the dryer code and renaming some functions. However, nothing is never that easy. My optimistic guess was that I’d add 100 lines of code and in the end it was more like 300. It was a fantastic learning experience.

A quick overview of my upgrades:

  • Added code to automatically pick a baseline for the current draw of each device.
    The original example required you to play with the values a bit to define the “off” value for the dryer. I added a loop to take the state of both washer and dryer at startup and set the baseline values automatically.
  • Made it so both devices would pull a random string from a MySQL database.
    By moving the strings of the Arduino and onto the interwebs I made it so I can go to the web any time I feel like adding a new pithy quote. Before, if you wanted to add a new string you needed to change the code in a couple places, recompile and re-upload to the hardware.
  • Various changes to make the code ready to monitor two devices.
    There were some minor changes I needed to make to the main loop (move the status LEDs into washer or dryer specific functions) and fix the “takeCurrentMeasurement” function (it had the dryer pin hardcoded as A0).

 

I’ll share out my code, an updated circuit design as well as a quick write up on how I’m pulling random strings from the web. Right now, however, I need to go do a load of laundry.