Two Possibilities

January 26, 2011

Homebrew Temperature Controller

Filed under: Projects,Technology — Eric Friedrich @ 4:19 pm
LED Screen

Finished Product

Several months ago I heard some interviews with expert homebrewers advocating for better control of beer fermentation temperatures. The yeast used to ferment beer (producing alcohol and carbonation from sugars), is most effective in a relatively small temperature range. Above that range you may get off-flavors, while below it the beer may not fully ferment. The temperature in my apartments fluctuates quite widely, especially in the winter. We have a programmable thermostat in the apartment to keep it between 60 and 67 degrees, depending on time of day. Most yeasts prefer the 68-72 degree range, disliking temperatures down at 60 degrees. I needed some type of heater to warm my beer up and keep it at a constant temperature. As an added bonus, this project might be able to do double duty as a temperature controller for a sous vide water bath, but that’s another post. You can see the Temperature Controller in the photo to the right. A display shows current temperature of the sensor and what the set point is. The set point is adjusted with a potentiometer knob on the bottom of the box (not visible because of the lighting, but to the left of where the wires enter on the bottom). The “0″ on the bottom right of the display indicates that the relay is currently switched off. When the temperature drops enough, the relay switches on and the display shows a “1″ in that position. You can find links to the source code, schematic, board layout file, and parts list at the bottom of the post. Since there is no good licensing scheme for open sourcing hardware designs, if you use my board layout please at least give me credit. (more…)

June 24, 2010

iMon LCD and lcdproc

Filed under: MythTV,Projects — Eric Friedrich @ 2:13 pm

My current HTPC case is an Antec Remote Fusion. It has an iMon LCD on the front, being driven by lcdproc. Setting this screen up was one of the easiest parts of my MythTV install. I haven’t done any customization of the information shown- the defaults work great. While media is playing, it displays a progress bar of the viewers position in the file. On a menu screen, the currently selected menu item is shown.

I followed instructions from the codeka forums on how to install lcdproc. I downloaded the current release of LCDProc which was 0.5.3 at the time. The release notes show that support for the iMon LCD has been added. Once the software was installed, I edited the /etc/LCDd.conf file, changing the drivers line to read ‘imonlcd’.

I also updated the Protocol setting based on my current hardware. Running lsusb reported “Bus 003 Device 002: ID 15c2:0038 SoundGraph Inc.” According to the LCDd.conf file, a value of 15c2:0038 needs a Protocol setting of 1

  # Specify which iMon protocol should be used [legal: 0=15c2:ffdc device,
  # 1=15c2:0038 device; default: 0]
  Protocol=1

Then, I verified that the /dev/lcd0 device was present and started LCDd by running ‘sudo /etc/init.d/LCDd start’. Once I was sure everything was running satisfactorily, I setup LCDd to run automatically on each boot by creating a symlink in the correct /etc/rc.d directory.

MythTV was set to use the LCD screen by following the brief instructions on the MythTV wiki.

December 23, 2009

iPod Remote Display – Scrolling LCD Display

Filed under: Projects — Tags: , — Eric Friedrich @ 9:58 pm

One of the two main parts of my Remote iPod Display is the LCD screen. For now, I’ve decided to go with a SparkFun SerLCD display. The particular one I’ve chosen is red lettering on a black screen to match the interior color scheme on my car. The serial enabled LCD are extraordinarily easy to use. Only three connections are required, +5V, Ground and a signal pin.

On the software side, the Arduino environment makes serial communications a breeze. My initial test program was as simple as Serial.println(“Hello World!”);.

My current plan is to have the title and artist of the current song scrolling on different lines of the display. Elapsed time into the song, total time, and time remaining are options as well. Given the small size of the screen, I will probably stick to just the song title and artist. If I am able to remotely control the iPod, I may try to use the screen to display navigation menus as well.
You can see from the video below that the scrolling is not very smooth. The entire screen is repainted twice a second. I’m not sure how to make the scrolling smoother. I may experiment with repainting one line at a time.

Hit the jump for a brief code walkthrough.

(more…)

December 20, 2009

iPod Remote Display

Filed under: Projects — Tags: , — Eric Friedrich @ 6:22 pm

Keeping in line with my earlier iPod projects, this is the beginning of a build log for an iPod Remote display. I always listen to my iPod during my commute. One of the hardest parts of using an iPod while driving is checking the screen to see what song is playing or navigating around the menus. This can also take my attention away from the road, which is quite dangerous. While some new cars come with an iPod kit, my car doesn’t include one. This page documents the construction of a remote display for an iPod and (possibly) a module for steering wheel control of the iPod.

I’ll be using an Arduino Diecimila for serial interface with the iPod and to drive a 2×24 character LED display. I picked the display up from SparkFun with an attached serial backpack. Printing characters to the display is incredibly easy with an Arduino and its libraries. Look for more on that in an upcoming post.

Design Notebook Entry

I scanned in an early drawing of my plans for this project. You can see from the date, that I’ve been thinking about this for the last year. I’m hopeful that this build log will give me some motivation to get things moving again.

At a high level the design has three components. First is the iPod itself. Through the dock connector, the iPod is connected to the Arduino. The Arduino will communicate with the iPod over a serial protocol to retrieve the Artist and Song Information. Its not clear yet if the Arduino can also control the iPod to start songs, stop play or move through the menus. The ‘duino then displays the song info on an LED display, which will be conveniently mounted on my cars’ dashboard. The above scan contains some circuitry to adjust the iPod 3.3V logic levels to the Arduino’s 5V logic. It also contains some circuitry so that the iPod interface circuitry can also charge the iPod.

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