Welcome to the Solar Collector
Brainstorming and Development Page!


 

Home

Hot Air Collector

Hot Water Project 1

Hot Water & Space Heating

Solar Electric

Solar Construction 101

FAQs

Best Collectors

Simply Solar
Sign up Calendar Latest Topics
 
 
 


Reply
  Author   Comment   Page 2 of 46      Prev   1   2   3   4   5   Next   »
Garage_Hermit

Avatar / Picture

Registered:
Posts: 2,240
Reply with quote  #11 
Hi, Jamie,
Great reading !

I am currently plotting a similar T° sensor network, so I look forward to communing on the subject !
=================
Could I suggest that U post a brief note in the ARDUINO section at HERE...
http://www.simplysolar.supporttopics.com/post/arduino-links-and-discussion-6250231?pid=1277247650#post1277247650

that will link back to your current post, in order to enrich the knowledge base ?

Many thanks,

G_H

__________________
(1)  "Heat goes from hot to cold, there is no directional bias"
(2) It's wrote, "voilà" unless talking musical instruments...

jamieF

Registered:
Posts: 269
Reply with quote  #12 
I decided to work on getting my current sensors working with the arduino recording when the electric hot water tank turns on.  The sensors can measure current but without direct measuring the voltage I can't actually tell how many watts are actually being used.  The good news is I don't care.  I have a TED5000 and can read values from there.   What this will tell me is the time that the tank is actually heating the water.   If I log this long enough I'll get a good idea of my daily averages and then be able to compare that to after the solar is installed to know roughly how much I'm actually saving. 

The entire process is actually really easy but I didn't think of something and took 4 hours to get it right... 

the current sensors are Hall Effect current sensor +/-80Amps  from http://www.devicecraft.com  I've had these for a few years now but they were pretty cheap when I bought them off of ebay.  under $10 each.

wiring is simple enough,  5v, ground, data out goes to an analog pin on the arduino, and then an activate pin which you connect to ground to take a reading.  I permanently leave it active.

Programming should also have been really easy but I forgot reading AC the current goes both ways and will be moving in a wave.  I was just grabbing it and printing it and getting a random point on the wave.  It made no sense and I blamed my wiring....  4 hours later I realized the issue.    So now I take a reading every millisecond for 1 second I take the absolute value of that and do a little math then compare it to the maximum value.  If it's larger then it's the new max. In the end I output the max.   The value is not a real current reading but  I now get 0 when it's turned off and 110-120 when it's turned on.   

So I'll likely throw some logic in to the arduino code and have it return ON when it's on and OFF when it's off.  

While discussing arduino code   right now what I'm doing is network inefficient but it doesn't matter as the data is pushed on my local network to my server.  I'm sending every reading roughly every second.    It makes a lot more sense to watch for and send changes to the reading and just assume if you haven't heard about the sensor it's stable.  So I'll likely make those changes to the code soon.

simple test sketch code of the current sensor below

Code:

int sensorPin = A0;    // select the input pin for the potentiometer
int sensorValue = 0;  // variable to store the value coming from the sensor
void setup(void) {
  Serial.begin(9600);
 Serial.println("start ");
}
void loop(void) {
  // read the value from the sensor:
   Serial.println("Reading ");
  int max =0;
  int i = 0;
  while (i < 1000)
  {
  sensorValue = abs(analogRead(sensorPin))-509;    
  delay(1);          
  if (sensorValue > max) 
   { 
    max = sensorValue;
   }
   i++;
  }
  
   Serial.print("Voltage ");
   Serial.println(max);        
}
Garage_Hermit

Avatar / Picture

Registered:
Posts: 2,240
Reply with quote  #13 
PHEW !

I'm a bit surprised by all of that, but quite admirative nonetheless !

I've only ever seen hall-effect sensors used for position-detection... (automobiles...)

Would not a thermistor be a bit easier (although you DO seem to be a programming wizard !)

G_H

__________________
(1)  "Heat goes from hot to cold, there is no directional bias"
(2) It's wrote, "voilà" unless talking musical instruments...
jamieF

Registered:
Posts: 269
Reply with quote  #14 
This is where the fact that I'm  a programmer by trade comes in.   The code is pretty easy for me although I'm not overly familiar with the language that the arduino is programmed in.  

 My electronics on the other hand is entirely what I can learn from google... for instance I had to look up what a thermistor is.   If I'm understanding correctly they're used for temperature measurements.  My guess is they'll output an analog value which is fine but that means 1 per pin in the arduino and I've only got so many pins.  

The reason I went with the ds18b20's was I'm wanting to have close to 20 temp sensors in the end.    The DS18b20's work on something called the one-wire protocol and they're digital and have a unique id built into each sensor.   That allows me to chain up to 64 on one string and connect it to a single pin.  In practice I had issues with really long runs and lots of sensors so my longest is 5 sensors and 60' and that works without any issues.  

As well I just used 3 of the analog pins for 3 current sensors.   And I still have to use 4 more digit pins to all my to control 4 relays.   

At the moment I'm really liking the use of the screw shield and phone jacks to connect everything.  My small box is getting busy but the arduino still has 2 more analog and 2 more digital input/outputs so I'm likely done adding to it just as soon as the relay is hooked up.   

I have 6 phone jacks for individual one wire sensors to run on.  in my case these will all be temperatures but there are other sensor types available.  I have 3 jacks for current sensors only 1 currently in use.   And I'll have 2 jacks that control relay modules which have 2 relays on each.  One of those will be used for controlling the pump/pumps and one spare.   And it's completely stand alone just needing a network connection on my router allowing me to power down my PC but continue to run everything.  Wireless is possible but I cheaped out years ago when I bought the network shield. Total parts to do all of it is under $100.  Probably way cheaper if you buy the knock off boards. I wouldn't be shocked if it's possible to do for under $50 these days.

Anyway It's a beautiful sunny day so I'm going to dig the trench for the conduit that the temp sensors for the collector panel will connect through.  I need to track down an inexpensive water proof 4 wire connector so that the collector can easily be disconnected.  I'm thinking something automotive should exist and work.    I'd say I'm making progress but really I'm avoiding gutting the laundry room and finally deciding what to do for the storage tank.    I hate being space limited...

Garage_Hermit

Avatar / Picture

Registered:
Posts: 2,240
Reply with quote  #15 
OK, thanks for the explanations !

I thought I was going for a lot, with 8 temperature sensors on my dream-list [rolleyes]

==============
Waterproof connectors - Couple of links here ...

http://www.camerasunderwater.co.uk/articles/uw-connectors

http://www.ebay.com/bhp/4-pin-waterproof-connector

http://www.hellamarine.com/en/products/accessories/plugs/plastic-waterproof-plugs-and-sockets.html

G_H

__________________
(1)  "Heat goes from hot to cold, there is no directional bias"
(2) It's wrote, "voilà" unless talking musical instruments...
jamieF

Registered:
Posts: 269
Reply with quote  #16 
the temperature sensor list is

string #1
cold room (installed)
workshop (installed)
laundry area (installed)
kid 1 bedroom (installed)
kid 2 bedroom (installed)
master bedroom (installed)

string #2
office (installed)
rec room (installed)
master bedroom (installed)
living room (installed)

string #3
outside front yard (installed)
outside back yard (installed)

string #4
solar collector incoming fluid
solar collector outgoing fluid
solar collector panel left
solar collector panel center
solar collector panel right

string #5  
storage tank incoming domestic water
storage tank outgoing domestic water
storage tank return fluid from collector
storage tank fluid top
storage tank fluid bottom

That will use every one of my current temp sensors that I have on hand.  I'll likely order more one day as I want to do some wireless arduino installs to monitor humidity and temperature in my greenhouse and if that works well I'll build a couple of more to cover the kitchen and bathroom in the house as those areas are a nightmare to run wiring to.  I've seen a few examples on line and they're getting over a year on a single 9v battery.

I like lots of data [wink]

In the meantime the trench is done and conduit in place.  I found 4 bin connectors meant for hooking up trailers  cheap at a local store so I'll solder that on the end and pull through one night.   Rest of my afternoon I think I'll get the collector out of storage finish the soldering and see if I can pressure test it.  After that I can wire the sensors for it and start on the frame.   I've collected so many pieces over the years and they've just been sitting around.  It's nice to be making progress.   Of course the amazingly unseasonal warm sunny weather has me motivated at the moment.
stmbtwle

Avatar / Picture

Registered:
Posts: 2,804
Reply with quote  #17 
What's neat are the "one wire" digital sensors, you can put a whole bunch of them on ONE digital pin, the arduino addresses them and sorts out the replies...

The temp sensor is the DS18B20; it can return temps directly in Celsius or Fahrenheit depending on how it's addressed. Cheap, too.

http://www.amazon.com/gp/product/B00CHEZ250/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=1944687722&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B004G53D54&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=17BFTE2GE38E8VTTWMMA

http://bildr.org/2011/07/ds18b20-arduino/

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Garage_Hermit

Avatar / Picture

Registered:
Posts: 2,240
Reply with quote  #18 
Thanks, Willie, that is neat !

Can the sensor leads be extended, say by adding speaker wire, as some of my runs are pretty longish... 

G_H

__________________
(1)  "Heat goes from hot to cold, there is no directional bias"
(2) It's wrote, "voilà" unless talking musical instruments...
jamieF

Registered:
Posts: 269
Reply with quote  #19 
Yeah  I've been soldering the leads of mine to regular 4 wire phone wire and then just daisy chaining them.   Longest run is at the moment 60ish feet.   longest in the end will be 80 I'd guess. you'll want at least 3 wires as the 2 wire parasitic power mode gave me lots of issues on the longer run.   Hook up all 3 and they work just fine.
stmbtwle

Avatar / Picture

Registered:
Posts: 2,804
Reply with quote  #20 
Got it from Paolo... inventor of the Aretha.

Thanks Jamie I was wondering if the two-lead setup actually worked that well. 

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

 

web statistics