Anywhere I can read any more about this?
The main loop was just the standard socket server you'd find in a Ethernet module example and I wrote a Jenkins plugin that would connect on break and send the offending username over the socket.
There were at the time a number of examples showing how to control the USB launcher from Geekwire w/ an Arduino that I pretty much just copied.
Then again, you might work in one of those weird offices where trying to measure the distance from your desk to theirs is more awkward than repeatedly attempting to shoot your coworkers while you fine-tuned the numbers.
Neat project!
I tried some basic calculations, but as you could guess with a nerf dart, building HVAC, and all the other things going on it wound up being faster and easier (and again, more fun) just shooting until I was on target a couple of times.
After the first few desks it was pretty easy to get close on the first shot because you could generally know that 4ft left or right was about an adjustment value of +/- whatever from the last coordinate you had dialed in.
I was thinking a flat thermistor. Then I started thinking - what if it's not the power, but the freezer itself?
Now I'm getting into a battery to log when power is out, save that state, continue logging temps, then transmit after the wifi (assuming loss of power - although I have a UPS for the modem/wifi that will last a few hours) is available again. This obviously adds complexity.
Would love to hear your approach to that project....
Pretty sure it was my great-grandpa who taught me that.
The 2 biggest constraints I found were power and communication from within the freezer.
One promising approach was - a BLE enabled temp. sensor beacon with a coin lion battery - a nearby externally mounted unit (RaspberryPi) plugged into a wall socket as a relay - a small central 'black box' SSD/Wifi/router ground-station to collect, store and push the data to the internet
The biggest question was whether the beacon signal could get through the freezer walls. If not then I was going to look into the idea of some super flat cable to enable a wired sensor connection without compromising the freezer seal (like a meat thermometer in an oven)
That being said, I didn't exactly exhaustively detail the before and after performance of the freezer either. I used the smallest drill bit possible that would let me get a probe in there and everything else is external of the freezer down by the compressor motor where there is a lot of extra room- and input power to tap in to.
Side note: Is it just me or does it seem like you get asked this question frequently?
I have the 'button' circuit wired into an Arduino I/O pin just like you would an old normally open button. When the 'button' circuit closes the Arduino triggers a VERY audible siren I cut out of an old water leak detector. If I have 5 minutes above my temp threshold the siren goes off. I upgraded it over time to use a small LiOn battery and got a circuit to switch to it when incoming power is cut for whatever reason, and basically when in battery mode it's also siren time. I got through 10 minutes of siren battery testing before deciding it was good enough and I was tired of hearing it.
We've talked about doing something similar for the propane fridge and an activity sensor in my friend's cabin in remote central Oregon using a 3G breakout for communications but we've run into the issue that the 3G there is really spotty and we just couldn't reliably get a data connection out there. Also debugging electronics with no internet, running off generator and batteries, and in the dark because we were fishing all day doesn't lend itself to really getting the job done.
Since you have WiFi you may have what you need to do it more simply, although the 3G might be a safety net for the safety net once you get your solution done. My biggest problem at the cabin, besides the lack of cell coverage, is the lack of constant power. There's barely any solar power, and it's used to keep the batteries conditioned, and it's often weeks or months between people getting out there. I would think at your place you could pretty much just use my approach and add WiFi, or just use an ESP8266 instead of an Arduino and do everything else the same. The battery switchover stuff was the biggest pain in my butt, mostly just because I've not got a ton of LiOn experience.
EDIT: On the RTC and temp logging, it's really not necessary. I just did it to do it. You can use the oscillation ticks and a counter to get close enough. Hell, you can just bump the threshold up a little and raise the alarm as soon as you see it without logging anything and get a drastically simpler circuit.
http://davenewson.com/posts/2013/ambilight-with-teensy-2.htm...
Also works with e.g. XBMC. I'm hoping to get mine working with my FireTV.
Now- I'm DEFINITELY not an expert, probably barely mediocre with the EE fundamentals, but I did take a lot of EE and some robotics at Uni to get my degree in Computer Engineering. I am nothing more than a hobbyist but some of my cooler projects have been:
- Autonomous 4WD robot
- Quadcopter
- A USB nerf gun that shoots at the developer who broke the Jenkins build
- Used an electronic photo frame as a display to show happy birthday tweets and Facebook posts to my wife from all the friends and family on her birthday
- WiFi/Proximity garage door opener (before they were cool)
- Garage freezer monitor (after an accidental unplug that spoiled a season's worth of salmon and elk)
- A vending machine that let you pay with your work badge from 'points' you earned (this involved a Raspbery Pi and a surface tablet as well, but the Arduino was what actually controlled the vending machine)
I've done a ton of random home automation IoT gizmos, mostly just for the fun of it, and a lot of robot builds for the boys. But the reason I use a lot of Arduino is that they are pretty friendly to use, there's a lot of help when I'm stuck, and I often don't need more. When I do, sometimes I just add another Arduino (or 4) and use serial or SPI communications between them. I've got some PIC chips for stuff, and some other random chips laying around, but I get more done quickly with the Arduino.
Now, if I ever got on to an idea I wanted to make more permanent I would look elsewhere, but for a hobby, everything else provides more friction and ramp up in the few hours a month I can free up to work on stuff.
EDIT: I'll add I've gotten some ESP8266 chips/breakouts that I've gotten more used to and I may start using them in a lot of places I've previously used Arduino + WiFi because the WiFi breakouts use a LOT of the available I/O and are usually the most expensive part of a build. I think I have 2 or 3 that I reuse.