With some inspiration from the potential snow storm last week, I endeavored to test my emergency preparedness for heating my apartment when the power is out. I never did lose power, but the test was successful and I am happy to know that if I did lose power in the winter, I can keep warm at home.
I attached an inverter to a marine battery, then plugged in my Rinnai heater and it ran just fine. The Rinnai does buzz a bit loudly, but that's because the inverter does not produce a "true-sine-wave" signal. I tested the setup with a box-fan attached to the inverter as well and it worked fine.
With the fan and the heater both running on LOW the draw was 115W. Some quick and super dirty math approximations tell me that the battery (if fully charged) will run this about 11 hours. This would be longer if the box-fan isn’t running (less power would be used).
105 Amp hours (sticker value, full charge)
105 Amp hours x 12v = 1260 watt hours (approximate average voltage)
1260 watt hours / 115 watts = ~11 hours
Of course, the inverter can be run from any 12V source. My Honda Civic has an alternator with a faceplate rating of 70Amps. Some quick math tells me how much power this can potentially provide.
70 Amps x 12 Vdc = 840 Wattsdc
I believe the inverter is well within the ability for the alternator to run. So the car could potentially run the inverter as a generator as long as there is gasoline in the tank.
Check out the rest of the info and pictures at my blog.
Since my previous post I have added a couple additional temperature sensors to my piHouse project. One is an outdoor temperature sensor that I previously programmed but never installed outside, and the other is a new sensor in my bedroom. This involved some hardware planning and effort installing because I had to run a cable through the house and outside, but once I tested the new cable run, it was relatively simple to duplicate the software for the sensors I already had.
The part of this that took the most time was pulling the cable and then soldering the connections. The biggest problem I have is placement of the outdoor sensor. I am having issues with direct Sunlight.
Here are some highlights, you can find the whole story here. This time I also include some examples of the commands I use on the raspberry pi to obtain the data.
When testing my hardware connections, I use this command to ask the pi to take a reading and then display the result to the command line:
house@raspberrypi ~ $ cat /sys/bus/w1/devices/28-00000512f401/w1_slave 2>&1
The Laboratory B crew had a great time at this year's two day Champlain Mini Maker Faire! This year we had additional support from FairPoint Communications to allow us to teach kids & adults how to solder. We had really impressive students this year, many of whom have seen us before at the previous events. Many people were coming back for their second or even third time. Good work everybody and thanks for coming out to see us! As usual, if you had trouble with your kit or ran out of time please feel free to swing by the Lab, but let us know your coming (Info@labotatoryb.org) Awesome!
Laboratory B is all set up and ready to see you at Champlain Mini Maker Faire this weekend! The event is on Sat. October 4th 10am - 5pm, and Sun. October 5th 11am-4pm at Shelburne Farms in Shelburne Vermont.
Lab B has been at the Maker Faire since it started 3 years ago, and like last year and the year before, we'll be teaching kids & adults how to solder! FairPoint Communications made a donation to help provide kits, and we have four kits from SparkFun in the mix this year; Weevil Eye, Big Time Watch, Simon Says & Mr. Roboto.
From our excerpt in the schedule:
"Join the folks at Laboratory B for a self-paced soldering workshop. We bring the soldering irons and the kits, you bring the desire to learn. We will have kits from SparkFun and all the required supplies and safety gear for you to sit down and learn how to solder, and when you finish you take the kit home! Have you soldered in the past but are not familiar with some of the newer techniques such as surface-mount soldering? No problem! There will be beginner kits, intermediate kits, and advanced level kits to fit all skill levels."
In March I posted about using my Raspberry Pi to monitor my furnace and the temperature of my apartment. I moved over the summer and the new apartment does not have the same type of heating that the last apartment did. So I had to make some changes.
The Pi now interfaces with a Rinnai heater, which was slightly more complicated than the furnace thermostat.
Here are some highlights, you can find the whole story here.
I get asked about being a hacker, what's a hacker, isn't hacking bad etc etc, all the time. Thanks Nova Labs for putting together this video which says everything I would have!
Keep up with some of the Laboratory B open source code by joining us on GitHub!
Last weekend Doug whipped together a toy steganography device called "Stegosaurus" [github] -- it will take a PNG image, and using a (very very basic) steganography [wikipedia] algorithm stores a payload in the least significant bits of the color definition of pixels in an image. It's a node.js module, and you can even install it with NPM.
It could use a little improvement if anyone is interested in forking it! It needs some testing with binary files. It needs a way to store the length of the message. And ideally, it'd use a pre-shared key (maybe?) to allow you both: A. define where the payload is hidden in the image, and B. actually encrypt the payload (which is, as of now, unencrypted). Which makes it so it doesn't follow Kerckhoff's Principle [wikipedia].
...Unfortunately every single message is decoded as "Drink more ovaltine" [youtube] (...just kidding. it'll do whatever payload you want)
When Laboratory B got started we were excited about the possibility of other hacker/maker/community workshop spaces starting up and sustaining in Vermont. That's why we created Vermont Hackerspaces Inc as non non-profit designed to help others do great things. The Foundry is a community workshop getting started in the Northeast Kingdom. Building on the grit, and hard work they are going to bring together a community of creators, tinkers, crafter, artist and entrepreneurs. This great community is going to build a great new space for creation and innovation!
On July 7th, Vermont Hackerspaces Inc, agreed to become the Foundry's fiscal sponsor while they get started. The Foundry is looking to develop it's own 501(c)3 but it's a long when from getting going to handling your own books. Check out the website or Foundry's facebook page and Foundry Info Pack for more info.
I made an upgrade to my Lego key ring. Now With USB! Basically, I put a 16G flash drive into some Legos and put them on the key ring.
Here are a couple shots, you can find the whole story here.