Home energy data logging project

[strider3700]

The current sensors are still a bit of an issue for me. They work great for knowing when the unit is running but on the 220V stuff I haven't been able to calibrate it. In a different post back a suggestion of doing V*V* the resistance or something like that was made to work out actual C.

Part of the issue I'm having is I don't get a direct reading of V so actual wattage used is estimated. In the case of a fan at 1 speed and the hotwater heater on or off is good enough for me. For my washing machine or dryer I want to know actual consumption though so more work will be needed.

[strider3700]

More ds18b20 temp sensors arrived so I put 1 in the front yard and one in the back. The interesting thing, at least to me, was to make them survive the elements I took 3 or 4 inch long pieces of 3/8" copper tubing and slid the sensors into that. I then used big blobs of silicone to close both ends up hopefully making it water tight. The only issue could be where the wires go in getting jiggled making small gaps. We'll see if they hold up or not.

I had to change the code a big to get the sensors working. Basically add s3 and s4 since the arduino sensors arrays don't automatically grow. also I had a bug in the java code where sensors not already in the sensorlist where incorrectly reporting back as the last sensor that was in the list. Minor fixes but annoying to do while in the middle of datalogging.

[AC_Hacker]

strider3700,

I just got a post on my DIY datalogger thread suggesting I look into this open-source data-logging software.

I thought you'd be interested to know about this...

-AC_Hacker

[strider3700]

interesting. I'll have to dig into it a bit sometime and see what I can find. I'm starting to get tired of the csv file, manually calculate everything and create the graphs each morning method. I did take the time to do a rough floor plan of my house so that I can start adding temperatures to it for some realtime displaying. that would be very cool to have over the web.

[strider3700]

here's a step by step thread on getting arduino data flowing to mango. Looks simple enough
Arduino and Mango Step by step working example

[strider3700]

Ran into an interesting problem while getting temperature sensors to the two kids bedrooms and the workshop. Apparently too much wire connected to 1 pin on the arduino causes it to not read correctly. The one wire bus can handle something like 64 sensors. I was trying to get 7 and it just refused to work, everything returned as having an address of 00000000000. So now I'm going to figure out how to get two one wire buses running in the code. that hopefully fixes the issue. If not I'm in trouble since I still need to run at least another 200 feet of wire for the solar setup.

[AC_Hacker]

Originally Posted by strider3700

Ran into an interesting problem while getting temperature sensors to the two kids bedrooms...

If it's not something obvious like an open connection, you might be picking up noise from the AC wiring in your house.

Long low-voltage audio runs have to contend with this all the time. Microphones that have long lines use a "balanced" cable that has twin conductors inside a ground shield. Regular balanced microphone cable can get pretty expensive, but I have seen a version of it that is about 1/8" in diameter.

Might help you out.

-AC_Hacker

[strider3700]

ok the code was relatively simple to fix but my quick and dirty hack is ugly as sin. I just had to create a second instance of everything...

// Data wire is plugged into port 22 on the Arduino
#define ONE_WIRE_BUS 22
#define ONE_WIRE_BUS2 23
#define TEMPERATURE_PRECISION 9
#define delayTime 2000     // the delay before restarting the loop


// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);
OneWire oneWire2(ONE_WIRE_BUS2);
int woodStoveCurrent = 0;
int hotWaterCurrent1 =1;
int hotWaterCurrent2 =2;
int baseline =0;

// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);
DallasTemperature sensors2(&oneWire2);
// arrays to hold device addresses
DeviceAddress s1, s2, s3,s4, s5, s6, s7, s8, s9, s10;

void setup(void)
{
  // start serial port
  Serial.begin(9600);
  delay(1000);
  // Start up the library
  sensors.begin();
  sensors2.begin();

this of course messes everything up further down since printTemperatures wants sensors not sensors2... I'll have to write something smart one day for now it works kinda.

The current issue is the sensors on the end of the long wire both report back their address's but they give a temperature of 85 which is the default for the sensor. It's 1 in the morning so I'll have to figure it out tomorrow.

Also on the screwed up front after 15 years of service my $10 crap soldering iron from radioshack gave up tonight. If nicely electrocuted me to tell me it was going and now doesn't heat up at all.

<edit> OK I found the issue on the 85 from the sensor It was because of my crap hack and having sensors and sensors2. I forgot to tell sensor2 to request the temperatures... some serious thought will be required and then I'll refactor the entire arudino code to make it far less horrible to use. It should be doing a bunch more things like automatically knowing how many sensors are on the bus and handling them all rather then hardcoded calls to each and so on. One day... </edit>

[Jazzoo]

Quick note on electronics and silicone. If you like to use silicone as a water-proof agent and or encasement, make darn sure you use either "food-safe" or "aquarium" silicone for direct contact with any wires, PCB traces, component leads, etc.. Most gelling catalysts in Silicons are corrosive and over time may (read will) cause you sensors to degrade and or fail. Wally-word and Pet-Smart are two good sources. Personally I prefer Epoxy (much more durable).

[AC_Hacker]

Strider,

There's a guy named Travis, here in Portland who is making an Arduino data-logger board with time-stamp & on-board SD card for writing data to (tested to 16 GB).

One pin is already set up for 1-wire.

Default data logging every minute

He's a very friendly and capable guy.

...thought you'd be interested.

-AC_Hacker