Skip to main content

it's been a while (but not without updates!)

I did not have much free time to work on this over the last couple of months,

but every once in a while when I did remember (hard not to, I keep the robot hand right in front of the computer), I tried to do something, mostly in the hardware procurement side of things.

some of the things I ended up acquiring:

- Raspberry Pi Zero (also the Raspberry Pi Zero W, which has wifi+bluetooth internally, but I just received it today thanks to Mr. Arjun Rao), for more versatile control (also to make possible to connect to the Leap Motion)
- AA battery power holders, to use AA batteries to power the servos
- A PCA9685 chip, for multiple servo control
- various electronic circuitry (probably won't be necessary for this project anymore)

in addition, I was made aware of a nice project called Cylon.js and its sister project Gobot, which allows users to program microcontrollers using JavaScript and Golang, respectively.

I really wanted to try Gobot and take a dive into the Golang world, but it currently does not have support for the PCA9685, which Cylon.js seems to provide. 

with that said, and with a few lines of code, here is the result:


the control of the servos are done through the PCA9685 connected to a Raspberry Pi Zero (no more Arduino), and the servos are powered through the 4-AA batteries. 

the next step is to read values from the Leap Motion, which Cylon.js claims to provide. 

when that works, we are starting to reach a good place. 


Labels:

Comments

Post a Comment

Popular posts from this blog

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.
Post a Comment
Read more

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...
Post a Comment
Read more

alcohol sensor (and some patience)

Soldered the alcohol sensor into something that is connectable: I tried to connect this to the Arduino, as I had the appropriate circuitry, but I did not get any legitimate output from it. 5V going in, 5V coming out with no variations. Nothing seems to be awry in wiring, as the circuit seems to be grounded properly (and the 5V current is flowing).  There are a couple of potential factors as to why I'm not seeing any results: - I'm using a 10k ohm resistor, while some guides (and the datasheet for the sensor) asks for 100-200k. However, there seems to be a good amount of people using 10k and getting at least some kind of result. A batch of 100k ohm resistors I ordered is on its way, so I guess I can try with them when they come. - This site  claims that these sensors take 24-48 hours for its signals to be stable. It also tells me that I should not be powering the sensor directly from the Arduino, which I have been doing, out of concern that the power draw of ...
Post a Comment
Read more