ka1kjz

Constructed this tonight…

Its an infra-red emitter, and visible LED operational indicator to implement the TV-Be-Gone code on the Jeenode.

I’ll be porting Ken’s code over to the Jeenode tomorrow and testing it.  All indications are it should work.

waltham_outbound_t_station_022010

Originally uploaded by ka1kjz

Another test of the Flickr blog-this feature, now with more lines.  It would be nice if they would let me tag!  Perhaps the flickr tags translate over, I have not gotten into that habit over there yet.

Another facet of my many many hobbies is being a railfan. Though not as fanatical as some, who track train consists (the actual numbers of cars in a train, scary I know that term!), I am generally into the infrastructure of railroading. Stations, tracks, spurs to nowhere, old lines no longer extant, if they built it, I am interested.

This is the “outbound” (away from Boston, or west bound) T station in Waltham Massachusetts. Not alot to really see here, its a very small station, only 2 cars or so, where the smallest station on the Metro-North line in Connecticut is 4 cars, or roughly double this length.

I have other plans in Massachusetts this spring, so I hope to cover the T line more soon.

jeenode_temp_control

Originally uploaded by ka1kjz

This post was sent from Flickr, just trying out the Blog This function. Lets see how badly it munges my blog!

While poking around the various Arduino forums, I found some work by Ken Shirriff, a port of the TV-B-Gone code.  Stated simply, a TV-B-Gone runs through all the IR power codes, turning off (or on) most any television.

So couple the Jeenode with the Arduino TV-B-Gone code and the room monitor, turn off the TV after 2-3 hours of motion inactivity (no one in the room or they fell asleep!).

This code can also be used to turn ON the TV, as a security measure.  Add a sensor for current draw, and you will know if the TV is indeed on.

So… to the drawing board!

This is the first post on the new cloud server!   A test really, to make sure everything is working, I can write where I need to write, read where I need to read, and all that happy Linux stuff.

This has been quite an education.  Finding out how shady my old hosts and registrars were, how they refused to help me, offered me “free” months when I cancelled, and how the registrar of ka1kjz.com is delaying my domain transfer.

But, if you arent shy and willing to roll up your sleeves, get dirty, break things, and royally mess up, I strongly recommend you handle all your own system administration on a cloud server.  The nice thing about these, if my site expands, I can expand the server to match.  If I become the next amazon.com, then my server will grow with me, or the host will offer a dedicated package, all with ZERO downtime.

While driving, I came up with a bunch of ideas for use of these Jeenodes, mainly home monitoring and control.  In rough order of implementation:

• Attic fan control & reporting (underway).
• Furnace monitoring.
• Waterheater monitoring.
• Room monitoring (as shown on Jeenodes site).
• Air Conditioner control & reporting.
• Assorted appliance monitoring (refrigerator, stove, etc).
• Kill-A-Watt Reporting (a-la Tweet-A-Watt).
• Outdoor Environment (temp, baro, humid, etc).
• Outdoor monitoring (lights on, trips, driveway activity).
• Profit!

I was recently turned on to the concept of “cloud computing”, where there really isn’t a dedicated computer box, in a rack somewhere, but rather a whole cluster of them sharing resources and the like.  A friend and I have been hosting our internet radio station on one for the past month, and aside from it being incredibly reliable, it has also been an order of magnitude less expensive.  I decided to give it a try, and signed up for similar service through the same provider, Rackspace.

It’s now time to tell my stagnant, unreliable, expensive, webhosts to kiss my shiny metal….

I will be able to handle all my own hosting, down to the operating system level, I will have control over -everything-.  No more being at the mercy of my hosts to keep with the times, any stagnation will be my own fault.  I’ll eventually do e-commerce, again having complete control.  I basically have a scalable Linux computer, or many computers, out there on the internet.

So in the coming days, I hope to move this blog and my other domains, hamopensource.com and ronaldcbarnes.com over to the cloud.  This should be seamless and one day, your DNS server will simply be pointing at the new host.

It was frighteningly easy!!  The code is available here, jee_temp.pde, but will be quoted below, it’s that small.

First, the Modern Devices / Liquidware temperature sensor was not pin compatible with the Jeenode, so I tossed together a quick adaptor as shown in the picture below.

Then it was a simple matter of finding the proper I2C address from the Liquidware Library, writing the register, reading the results, and doing a little math.  As shown below.  Temperature is now stored in a float called “tempC” and ready for manipulation.

// Hooking up a TI TMP421 temp sensor via I2C.
//
// see http://ka1kjz.com/?p=520
// 02/21/2010 Ronald C. Barnes (ka1kjz@ka1kjz.com)
//

#include <Ports.h>
#include <RF12.h>                             // needed to avoid a linker error  

PortI2C myport (2 /*, PortI2C::KHZ400 */);    
DeviceI2C temperature (myport, 0x2A);         // I2C addy of 0X2A

float tempC = 0;

int tempC_hi = 0;
int tempC_lo = 0;

void setup()
{
 Serial.begin(57600);
}

void loop()
{
 temperature.send();
 temperature.write(0x00);        // high byte is on register 0
 temperature.receive();
 tempC_hi = temperature.read(1);
 temperature.stop();

 temperature.send();
 temperature.write(0x10);        // low byte is on register 0x10
 temperature.receive();
 tempC_lo = temperature.read(1);
 temperature.stop();

 tempC = (float)tempC_lo / 256;  // make low byte into remainder
 tempC = tempC + tempC_hi;       // add high byte to make total temp
 Serial.print(tempC);
 Serial.println(" Deg C");
 delay(1000);
}

This should work…

Prototyping and calculation of the LED current limiting resistor starts in a little while.

Jeenodes, small form factor boards with an Arduino core and a built in radio.  Not as functional as a Xbee or The Zigbee System, but for most applications, more than adequate.

I had been doing some work with thermostatic control, as I want to build a new house thermostat, with some features that are not found on commercial programmable thermostats.  Also, I’ve been meaning to add fans to my attic, to vent out some of the summer heat, and these boards are a perfect fit.  The Arduino core will handily perform the thermostat function, and the radio can report the telemetry with no wires.

I’ll devote my old Win98 laptop to the task of displaying house telemetry and will be more than adequate.  I’ll use something like Processing or some other graphics rich development environment, to continually display home conditions.

The Jeenode comes as a big bag of parts, assembly went quickly, about 1/2 hour, but I’m pretty advanced.  The average person, maybe 1 – 2 hours.  Of the two that I’ve built so far, both powered up on the first try!

Next step, to adapt the Modern Device / LiquidWare temperature sensor to the Jeenode.  Shouldnt be too hard, just have to actually LOOK at the source and change a few pin assignments around.

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