Having recently purchased an arduino and learning some about the programming language, I quickly decided this could be a perfect solution.

Goals:

• Most basically, log beer temperature for later review to a removable SD card.
• Monitor/display current temperature
• Monitor/display running minimum and maximum temperature.

For those out there intimidated by the arduino or programming, it does come with a small learning curve, but it is a totally doable project. The key to my success with it was trial and error. You’ll learn from your mistakes and improve on them. Plus, what better way to learn programming or electrical engineering than for beer! This is composed from a multitude of tutorials, so go pour a homebrew, and lets jump in. Cheers.

LCD

Credit: arduino.cc

I began with interfacing my LCD screen. This was a necessary part of the system for monitoring the temperature. I personally ordered a simply serial 16×2 LCD from SparkFun here. I then followed Arduino’s online LiquidCrystal Tutorial for a wiring diagram. I most simply just followed the image to the right, but the link above will explain in greater detail. Note: You will need a 10k potentiometer for the contrast. Without it, no matter if you ground the contrast or wire it in to 5v or 3.3v, the contrast will not be sufficient to read. Your LCD will be displaying, but you will not know it. I used this guy from the local radioshack, You’ll have to turn it at least 4 or 5 times to get the contrast to a legible setting. Begin with wiring this guy up and pull up the LiquidCrystal examples and make sure you comfortable with running HelloWorld. Review the code a touch so you’re familiar with lcd.print(), etc, and how the library works.

I moved D11 and D12 down to D6 and D7 just for organizational reasons, if you do this, be sure to go through the code and sub in 11 for 6 and 12 for 7. For the record, I just very un-professionally wired my lcd by bending 10 different copper wires through the LCD pinout. This is strongly discouraged. I will eventually solder it all. You can do it the way I did, just using 5 strands of speaker cable (two wires on each cable) but  just know that wiggling and shorting can cause some frustration. You have to make sure none of the copper is dangling around and shorting.

Temperature Probe

I ordered two DS18b20′s from SparkFun. One for fun & testing purposes, and another for actual use submersed in the beer. I have considered many options for how to get the temperature of the beer, and feel that a submersed probe is the only way to get a true, accurate reading.

The temperature probe and wiring is pretty straight forward. Its a digital pin, with a 5v and a ground. You will need a 4.7k Ohm resistor for the DS18b20. Again, I picked up an 8pk of these for like $1 at the local RadioShack. The image at the right is directly from the manufacturer. If you’re using the probe only (no waterproof wiring), note the indent and make sure you know the difference between GND and Vdd (5v). I don’t believe it’ll hurt anything if you wire it wrong, it just won’t work. If you’re using the wired waterproof probe, then black is ground, red is Vdd, and white is data.

You will need to download the 1-wire library (from Paul Stoffregen) and add it to your arduino library. This is usually located in your Documents folder under arduino. Unzip and copy the folder right into the Libraries folder inside Arduino.

I added an ugly wiring schematic I drew real quick for clarification with the resistor. The resistor just goes right in on the data pins and the 5v, between the arduino and probe. The data pin can then go into any of the digital pins. So just choose one and make sure it set right in the code. If you use my code, i put it on digital pin 9. For easier prototyping, I just use a simple breadboard.Open the arduino examples and select the 1-wire’s ds18b20 example. Play around with it. Make sure you get it working and reporting to either the serial monitor, or better yet the LCD. You will have to play with LCD display anyway, might as well do it now. Get that temperature displaying on the LCD. At this point, you should have a good idea of what the house temperature is. If its 72 or warmer, go pour yourself a pale or ipa. If its cooler than 72, go pour yourself a nice stout. Then come back, we’re not done here.

SD card & logging

Okay. At this point, hopefully you have the temperature probe and lcd working. You should also be at least 2 beers in. I’ll take a moment to go refill….mmm, irish stout tribute. So I really wanted a way to be able to review the temperature data after a full fermentation. A quick easy way of doing this is just telling the Arduino to dump the temperature it is already reading at this point to the SD card every so often. I think a 5 minute resolution will be more than enough. I purchased this SD Shield , again from the local RadioShack. It was only $14, and the well worth the investment for wiring purposes. Throw that guy on the arduino and make sure you select the correct switch if you’re using the same model as radioshacks. There is tiny switch that selects between SD and microSD. The SD shield uses D10, D11, D12, D13, so you if you placed your temperature probe on one of these, just move it to another digital pin, and replace the code with right pin.

Now we need to add another library. For the purpose of the implementation we have, an append type application would be best. I don’t want to lose the logged information I already have, and I dont want a new file each time I log, so I actually added the SdFATlib libary to my arduino IDE. Inside that library, there is an append example, exactly what we need! There is already an SD library of sorts supplied with the Arduino, but I liked the append example and just never went back after that. For our append program to do what it needs, there needs to be a pre-existing file in the root of the card. So I put the SD card in my laptop, formatted it (for good measure), and added a file to the root title “beertemp.TXT”. Note that file names on a FAT32 disk need to be 8 characters or less, with the 3 digit extension. Choose wisely my friends.

Now that we have the file in the root directory, put the SD card in your arduino SD shield, and pull up the append example from the sdfatlib library. Upload it and then check the SD card. Play with it until you have the example appending happily. Now you’re good to go.

All together now

The program linked here is the one I’m currently using. It has a 2 sec monitor resolution, and a 5 minute data log resolution. Read through the code and familiarize yourself with it. I have commented it to the best of my ability. I will allow comments on this post so you are free to ask questions or pose improvement ideas.

My program, free to use, modify, share as needed.

I have combined all three of the above examples and necessary code bits into one streamlined program that I feel works well. This is in no way a perfected approach. I’m open to suggestions and pointers. I know much improvement can be made. Good luck!

Prosit! (especially to you guys over at /r/homebrewing!)

Those who know me, know I enjoy beer, and good beer at that. Naturally, a couple years ago I decided to try brewing it on my own for an unmatched experience and quality. Since then, I have brewed many good, and many terrible batches. Learning all along the way.

Debut Brew Stand, Thanksgiving Pumpkin Ale

I built an apartment friendly brewstand that is 100% electric. Being in a one bedroom apartment, this posed a challenge I was gladly ready to accept. So here’s the brew stand built and ready for debut brew, a Thanksgiving Pumpkin Ale. But I quickly learned that a 4500 watt element on 240v very quickly brings wort to a boil, and no way will hold a calm rolling boil. Rather, 4500 watts will throw beer across the room its so hot. So time to figure out how to control my boil other than simply plugging straight in to the wall.

Enter pulse width modulation, or PWM as you’ll typically see it. PWM is not as fancy or scientific as it may sound. What PWM does is limits the time that the element is on following a determined cycle. So in our case, we are looking for a way to put, say 50%, of the power from the element into the boil. The easy way to do so is simply power the element for 1 second, then un-power it 1 second. Now, over the course of 2 seconds, the wort received 50% power. And thats exactly what PWM is, using a cycle of time to turn something on and off to provide a reduced power output.

Pulse Width Modulation and the Arduino

Arduino PWM

I would use an arduino coupled with a solid state relay (ssr) to do this. The arduino will be programmed to provide a 5vdc signal that is controlled by PWM to turn the SSR on and off. For simplicity, I added a potentiometer to control the power percentage. My code uses a 2 second cycle. so 50% power is 1 sec. on, 1 off. 75% power is 1.5 on .5 off… and so on. Now the potentiometer receives full power, and based on where the pot is dialed in, returns a fraction of that. So the code reads what signal it gets back, does some division, and provides a number, 0-9 for the total power. Pot turned all the way closed (or on) is a 9, and 0 being circuit open, or off. Then the arduino easily takes the fraction on and computes a on off cycle appropriately. 0 element is completely off, 9 element is 100% on. I additionally added a simple 7 segment LED digit to relay to me what power I have selected.  I’ve attached the code below for you who are interested in the code to do this. Feel free to use and edit it as you may need. Additionally, check out the youtube video that shows it in action and talks a little bit about it.

Arduino PWM Code

Lets look at some southeast Texas Snowfall History. Winters of 08/09, 09/10, and 10/11 had significant winter weather events. The first two being snow events, and the last event being a bunch of ice. After sifting through much climate data, I can’t find anywhere terribly obvious that three years in row there were significant winter precipitation events. Does that mean it hasnt happened. No. Does it really mean much of anything, I guess not really. But it is interesting. A strike of curiosity. This past summer was record breaking enough. It just seems a little odd all of this record breaking and climate abnormals. If you read this within a couple days of its publishing, you will be able to take notice of the current weather set up… cold front passage with some precip, AND some post frontal precip. This early in December, the fronts just aren’t cold enough to provide freezing precip. But northern Texas will see something a little different. It will be interesting to see what the rest of the season brings. Not to mention were in a La Niña right now, as we have been for the past 2 years or so now I’ll remind you. Statistically, La Niña has its biggest effects on us during winter and moderates us, AKA it warms our winter and reduces precipitation. Interesting that we’ve been in a decent La Niña and been having annual precip events. It should be understood though that La Niña is a very broad and wide influence, you cannon attribute any daily events to something such as ENSO (La Niña and El Niño). Just all food for thought. Remember, the best thing we can do to better understand weather is to take everything with an open, but inquisitive mind. Don’t take anything for certain, you’ve got to question it all yourself. In weather nothing is exact. Just look at the last couple winters…

Tropical Storm Maria Forecast

Allow me to use the current NHC forecast path for tropical storm Maria. We are all familiar with this little graphic that they put out for the forecast track of a storm. The cone varies with each storm considerably in size, length, etc. Now what does the area inside the cone really mean? The cone defines where the CENTER of the storm could be. Its that simple. The cone does NOT stand for area that will be affected by the storm. You can easily be outside the cone, and if the center of the storm tracks along the edge, still feel the effects. Essentially to build this image, the National Hurricane Center makes their best effort forecast track for the storm, and then account for statistical and model error, expanding from that center line of the forecast track. So here is what you should take away from this post: white area inside cone = possible center of storm. And keep in mind, these cones can change a bunch with new forecasts, so keep an eye. If you read that last post, you already know how unpredictable these guys are.

Lets start off with one aspect most people have a general understanding of, Sea Surface Temperatures (henceforth SSTs). For general reference, 80º F is the commonly accepted minimum SST to allow tropical cyclone formation. Now, with all the heat this summer, especially down along the gulf coast, we may be led to believe that Sea Surface Temperatures (SST’s) are rather high this year. The map to the right displays the SSTs as of July 24, 2011. Still kind of hard to read, but will be good for comparison in a minute. For record though, much, if not almost all of the Gulf is at or above 85º, some regions closing in on 90º. The rest of the tropic zone, extending from the Yucatan out through the Antilles and all the way over to Western Africa, is in the 83º/84º range. This sure seems like it would be a breeding ground, but before we make any conclusions, we need to dig a little deeper. Lets think back to the year 2005. By far the most active tropical season on record. Shattering older records. 15 Hurricanes, 7 Major (Category 3+), 28 total storms (one of which formed in January!). What were the SSTs at this time that year? The map would make it appear that while this year we have pockets of warmer water, 2005 had a larger spread and presence of warm water. Of course, we’re talking within a degree or so of each other. Panning through National Buoy Data Center’s archive though it would appear that at the end of July, average Gulf/Caribbean temperatures were around 85ºF. Lets look at one last case, just again for comparison. Let’s take 2009 for example. An extremely quiet year boasting a measly 9 storms, only 3 of which would obtain hurricane status. Well judging its map, it look about on par with the other two years, and looking at archive bouy data again, it is. Well great, that didn’t clarify a whole lot now did it? Good to know though I guess.

Another big player in hurricane formation is upper level winds. Hurricanes require a very easy going, quiet atmosphere to develop and maintain organization. Strong winds high in the atmosphere can tear a storm apart or inhibit it from ever beginning. A big player in this field is ENSO, or more commonly known as El Niño. While we are almost completely incapable of forecasting ENSO, we are able to record it and learn from the past. El Niño is known to encourage hurricane activity, and likewise, La Niña is known to discourage it. Currently we are leaving a rather strong La Niña, and would like to assume will be entering an El Niño, however that we cannot be sure of, we can only continue to measure it to see where we currently are. For reference though, 2005 (our active season) was a moderate El Niño, and 2009, a transition year (at least the summer was) from La Niña to El Niño, sliding in right between the two. Well once again, not real helpful to our purpose here, but good to know.

In case it isn’t clear yet, forecasting how active a hurricane season will be is extremely tough. There are many, many aspects that will just depend on the atmospheric dynamics at the time and place of a storm if and when it forms. The best bet is to just stay updated on the tropics if you live in a Hurricane prone area. It’s not a bad idea to have a rough plan in place of what you and your family will do should a storm be headed for your hometown. Keep in mind how quickly these storms can form and how quickly they can, and do, shift their travel direction. A rough rule to play it safe is if you are within 200 miles of the forecast cone, not the track, but any of the edges of the cone, you need to be preparing for the possibility of a landfall. Many of the Gulf Coast states could use the rain, I just hope it doesn’t come at too much of a cost.