• Let's do this backwards

    juancubillo • 08/24/2014 at 07:44 • 0 comments

    O

    k.. Let's say my planning stages are complete. Not really.. but it's time to start building. My project involves wireles slave modules.. that talk to a master... that displays data on a webpage. So what am I going to start building first? The webpage!
    Apparently if I want to use python to develop my interface the best option is to use Django 

    No... not that Django... This Django: https://www.djangoproject.com/

    I've been reading about it and.. well... me like it.

    I'll try to build an interface with randomly generated data in the next days.

    Wish me luck!

  • Just in time

    juancubillo • 08/21/2014 at 06:32 • 0 comments

    I just posted the video description for this prize entry. Here's the link!

  • Website

    juancubillo • 08/21/2014 at 05:32 • 0 comments

    The website will be programmed in python... why? Cause i've never used it before. I want to use this project to learn.

    Anyways... thought I might write the web interface in python and save the data in a mysql database. There are probably better options... but I don't know them. I can always port to a better code if required. Let me know if you think tI should use something else... 

    HTML5? I've no idea...

  • Powah!

    juancubillo • 08/20/2014 at 08:31 • 0 comments

    Haven't thought about power... I don't really want to use batteries because.. well.. 2or3 AA batts per module x 60 modules starts to get expensive/annoying battery-wise.

    If the modules are going to be contained inside datacenter racks... then why no use USB power? They will only use a small amount of current (much less than the 500mA limit for USB) and USB ports will be wide available. External PSU jack can also be added.

     - "Security" might be a concern with USB-attached devices so the modules will only use the USB power lines. D+ D- won't be wired at all. This will isolate any "interference" between the arduino and the server/computer.

  • Sensors

    juancubillo • 08/20/2014 at 05:33 • 0 comments

     - Humidity: HIH-4030

    - Temperature: Thermistor inside a metal case?

     - Open/close doors: Reed switch + magnet?, Microswitch?, 

    **NOTE: Could it be possible to add a gas detector to detect fire? Trigger an alarm maybe?

  • Brains

    juancubillo • 08/20/2014 at 05:28 • 0 comments

    Central unit: 

     - Will be a raspberry pi. That's decided. No tech considerations given. I want to use a raspi. Period.

    Modules:

     - Arduino of some sort. Needs to be small. Digispark maybe? Microudino? Any other options? 

     - In later stages of development may be changed to a custom board.

  • Communications

    juancubillo • 08/20/2014 at 05:26 • 0 comments

    Options to transmitt data?

     - IR? Requires line of sight (kindoff..). One way only...

     - 433MHz modules? Need two per modules... RX and TX. Bulky.

     - NRF type transceivers? Two way communication. Small. 

     - Bluetooth? Never used it. Seems ... complicated.

     - Zigbee. Never used it. Don't like it's name.

  • "Front Image" uploaded!

    juancubillo • 08/20/2014 at 05:13 • 0 comments

    Ok... I had the idea of what I wanted... I just couldn't visualize it. A few minutes googling images, some MSPaint (anyone know a nice simple linux alternative?) and now I can see it:

     - Each rack has a small arduino conencted to sensors and an RF link (NRF24L01?)

     - Central unit will be a raspberry pi. Why? Because I have never used one and this gives me a nice excuse.

     - RasPi will gather data via another rf link and present it on a custom website. A "heatmap" would be a nice addition. Not just plain sensor data numbers...