alcohol sensor (it's working!)

Built a voltage-regulation circuit that was shown here (seems like this layout is uncommon, as other resources seem to agree on using a circuit with a 10uF and a 1uF capacitor. I already ordered a 1000uF shown here, so I'll go with this). Seems to work like a charm. I connected it to the alcohol sensor circuit using a 9V battery as input, but it still did not seem to work:

Output voltage was constant @ ~5V. Expected behavior is 5V = maximum alcohol level.

After some thought, I just decided to try wiring the alcohol sensor circuit again. I was almost sure I had the wiring right before, but once I connected it after the re-wiring, output voltage started dropping:

Voltage dropping. As stated in the previous post, the sensor requires a 24-48 hour calibration time (to reach 0V state)

Two key functionalities are now usable. Time to start putting them together.

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nodejs migration

Having been playing around with NodeJS recently, I (naturally?) started re-writing some of the OpenSesame code using Node last night. I think I've only worked on it around 2 hours so far, but I've already set up a basic client interface (a socket.io chat tutorial rip) with a server that the Raspberry Pi can connect to and receive requests to open the door. This is probably due to socket.io's socket management (socket.io is the WebSocket module for Node); for my first implementation, I had to manually write up a structure that managed sockets, but that is pretty much handled by socket.io. Also, the servo control logic is pretty much recycled (and the Raspberry Pi code is still Python), and I do remember spending some good time figuring that out. Cool neverthelss. I'll probably keep both versions around.

quick recollection on setting things up

If I can swear that the password is correct, then it's possible that I'm getting the ID wrong. Hadn't logged into the web server in a couple of months and was unable to SSH into it. After an hour or so, I ended up deleting the instance and recreating a clean instance (read: erasing everything). I then realized I'd been putting the wrong ID. apt-get install sudo apt-get install Anyways, some links I visited when setting things up (pretty much a dump of whatever I copy-pasted to notes) : Raspberry Pi http://www.makeuseof.com/tag/optimize-the-power-of-your-raspberry-pi-with-raspbian/ Logging http://docs.python.org/2/howto/logging-cookbook.html Tornado - Python webserver that supports Websocket http://stackoverflow.com/questions/2924991/what-popular-webservers-have-support-for-html5-websocket http://lowpowerlab.com/blog/2013/01/17/raspberrypi-websockets-with-python-tornado/ http://stackoverflow.com/questions/11695375/tornado-identify-tra...

how the fingers work

the fingers are moved using wires and tension. each finger is looped through with a wire/string/line in a top-bottom fashion. when the top wire is loosened/bottom wire is tightened, the finger curls in its joints, resulting in a "bent finger". you don't have precise control of each joint movement, but it is simple enough to be controlled by a single actuator (in this case a servo). here is me just using my own hands as an actuator: here it is hooked up to as servo and controlled by a potentiometer: the movement is not smooth because 1) it's controlled by a potentiometer that I am controlling, as seen in the background, and I was unable to move it all the way with one smooth finer motion. 2) the tension in the line was not entirely tight. I need to learn how to tie these well. now I have a get a bunch of servos. much credit and thanks to Inmoov once again.

the quest for robots

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