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RESISTORS — and use with DS18B20 September 17, 2011

Posted by rik94566 in 1-wire, aquaponic automation, aquaponics, arduino, CAT 5 Cable, DIY aquaponics, DS18B20, indoor aquaponics, indoor gardens, indoor growing, One-wire, sensor, Sensor Hub, Stainless Steel Temp Probe, Temperature Probe.
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In order to read DS18B20 IC’s or temperature probes a resistor is required. The standard one used in almost all work done on breadboard examples are 4.7K ohm. Upon researching work done with 1-wire temp sensing most people are only working with 1 to 2 DS18B20’s and most of this is with breadboards. In a few cases people are using 3 or 4 only. I have found no cases where anyone is working and in production with 5 or more DS18B20 probes. So I think this is somewhat new ground. That being the case, there is a lot written that as you increase the number of DS18B20’s the power draw becomes greater and you need to decrease the resistor size. The common thought is to go to 2.2K ohm resistor. If that does not work the next size to work with is 1.0K ohm. Well this will be my next testing platform. I will be testing both the 4.7K and 2.2K resistors with up to 10 DS18B20 probes to determine what works and what does not work. Along the way I will determine what happens and how it happens and where the breaking points are in the hardware and the sketches. Will be fun stuff.

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Load them up — 5 (DS18B20) Temp Probes — SKETCH CRASHES September 10, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, CEA, Controlled Environment Agriculture, Crop, DIY aquaponics, DS18B20, indoor aquaponics, indoor gardens, indoor growing, Sensor Hub, Stainless Steel Temp Probe, Temperature Probe.
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Well I got it together now and fired everything up — and the sketch crashed…  Here are the details of what it looked like.

5 probes and connection through harness

I put the 5 probe sketch I was using up on google docs and made it available at this link:

https://docs.google.com/leaf?id=0Bw1rZ4X2iJkmYzQyOWI0YzMtMzNlYy00NWNjLTg1ZWYtYzUxODUyM2VhNjlm&hl=en_US

If  you have a problem with the sketch just email me at rik94566@gmail.com and I will send the sketch to you.

Here is what it looks like as it was coded:

5 probe sketch as it ran

Here is the result when I ran the sketch:

Sketch only went this far

Interesting thing is that I worked my way up from 1 probe to 5 probes.  Before I started I checked all slots on the harness to make sure there would be no problems with the connections. Everything worked fine through 4 probes.  Here is what it looked like running 4 probes.

Now the fun begins..  get to figure out why this does not work with 5 probes. Found out some other things about deviceIndex while I was loading up all the probes.  Will blog about that next and present concepts that help drive the One-wire protocols.

Keeping track of my Probes (DS18B20) September 8, 2011

Posted by rik94566 in aquaponic automation, aquaponics, CAT 5 Cable, CEA, Controlled Environment Agriculture, DIY aquaponics, DS18B20, indoor aquaponics, indoor gardens, indoor growing, Sensor Hub, Stainless Steel Temp Probe, Standards, Temperature Probe.
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As I expand the number of probes that I am installing I need a way to track which probe is which.  When I first started I would wrap white tape around the outside of a probe on the wire lead and use a water proof marker and give the probe a index number.  Since I needed different lengths of wire leads and the fact that the wire is placed in water and under gravel situations the tape idea did not work to well.  So next best thing was to engrave the Stainless Steel probe ends with an index number.  This solved my problem in tracking each probe.

Dremel engraving tool and temp probe

engraved probe - need more practice - but getting better now

SUGRU — makes a harness possible August 21, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, CEA, DIY aquaponics, DS18B20, Hacks, indoor aquaponics, indoor gardens, indoor growing, Rj45 connector, sensor, Sensor Hub, Stainless Steel Temp Probe, Standards, SUGRU, Temperature Probe.
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In order to connect up 5 DS18B20 temp probes and make sure all the wires and connectors work correctly took some effort.  The fact that a pull-up resistor is required to take readings was an issue for me.  I have been using 1/4 watt resistors and in tight spaces my resistor wires kept breaking off.  So I needed a way to connect it all up and be protected.  Sugru saved the day.

Sugru made a strong bond

I showed you the end product as that is what most people are interested in.  But it is important to understand how the end product was created.

Here is the starting point:

pull-up resistor configuration

Spacing of the wires and resistor is a big issue here, as if the spacing is off the connectors will not fit into the holders correctly.

one connection made

Next trick was to get 5 connections completed.

5 connections made

bend it just right to get correct spacing

side view

Front view

end product

Now it is possible to continue testing my DS18B20 temp probes with more than 2 probes.  This creation will allow me to build a temp probe hub using Cat 5 cable and RJ45 connectors.  This harness will also make it possible to stay with my basic premise of being able to replace any component in my systems with in 5 minutes.

NEXT GOAL — Temp probe Hub (DS18B20 & RJ45) August 12, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, CEA, Controlled Environment Agriculture, DIY aquaponics, DS18B20, indoor aquaponics, indoor growing, Instructables, Rj45 connector, Stainless Steel Temp Probe, Temperature Probe.
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4 comments

5 buttons and 5 temp readings

Here we go….  The goal here is to create a DS18B20 hub using RJ45 connections and have results displayed on a computer screen or LCD.  I want to achieve the functionality of a PINPOINT Temp unit I am currently using.  You can check it out here:

http://www.marinedepot.com/thermometers_refractometers_hydrometers_american_marine_pinpoint_wireless_thermometer-ap.html

This unit allows you to see individual readings from each one of the probes you have connected and you also have the option to rotate through all the probes and see their values.  The Pinpoint unit is limited to 4 probes and I know it is wireless, but that will come later.  It is totally possible with arduinos and the things we are learning here.

When I get my hub working it will hold 5 probes and the analog button panel will display the correct temperature for the button pushed.  Button 1 gives reading from probe 1 and so on.  If all goes well,  I will be able to hold down button 1 for about 3 seconds and then all temp probes values will be displayed in order starting with the first temp probe.

MANY THINGS TO WORK OUT:

  • Sketch for analog button panel.
  • Reading individual temp probe values using HEX code.
  • Determine the resistor values needed when working with 5 probes.  ( did a lot of research on this one)
  • Will I need external power supply.
  • Figure out how to connect my power wires and signal wires with the correct resistor and be strong enough to hold up to being bent without breaking the resistor wires ends.

If all goes well I will be able to create an Instructable so others can build their own DS18B20 hub and use them in any location that people want to track and drive control of enviroments with tempeture results.

So stay tuned it should be a fun and exciting fall….

DS18B20 – 2 wire configuration – 2 Temp Probe — inconsistent results June 18, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, DIY aquaponics, DS18B20, Hacks, indoor aquaponics, indoor duckweed growing, indoor gardens, indoor growing, Rj45 connector, sensor, Sensor Hub, Stainless Steel Temp Probe, Standards, Temperature Probe.
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7 comments

Being that I have a testing platform and the fact that I want to learn everything there is to know about how the DS18B20 behaves and performs I decided to test a 2-wire configuration using 2 temp probes.  Results were inconsistent.

Here is how I configured the RJ45 testing hub.  I kept the arduino side the same as in the last blog post and only changed the wire configuration on the hub side.   I configured the hub the same way for both position 1 and 2.

2-wire configuration at hub

The inconsistent results were generated only on position 2 of the hub.  I have no idea why this occurs.  It seems to be at random as to when it occurs in the cycles of the sketch.  With results that are inconsistent it is clear that it is not a good idea to use this for important work.  For 2 or 3 cycles normal temperatures report out and then the 185.00F is reported out.  Strange stuff.

I am using the same Sketch posted earlier for testing 2 Probe DS18B20 sensors.

Resuts from Sketch (inconsistent results Probe 002)

Doing a little research I found that inconsistent results are experienced when adding multiple DS18B20 sensors when using the parasite power mode, which is the 2-wire configuration I have working here. I will test other situations now and try and determine issues with this power modes and configurations

Reading Two Temp Probes — DS18B20 June 14, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, DIY aquaponics, DS18B20, Hacks, indoor aquaponics, indoor gardens, indoor growing, Rj45 connector, sensor, Sensor Hub, Stainless Steel Temp Probe, Standards, Temperature Probe.
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Reading two (2) DS18B20 Temperature Probes requires an added level of complexity.  You need to have a sketch that will accommodate the addition Temp Probe and report out  the readings.  You need to be able to tell each Temp Probe apart and know which probe is being read and when. Using the RJ45 2 jack hub I constructed I added the 4.7K ohm resistors and wired up both sides of the hub. This is the same as the 3-wire configuration test and talked about in prior blog discussions.

Hub wired up for testing

Here is what the connections look like on the arduino side of the test.

Arduino connections for 2 Temperature Probes

Next I need to build out the arduino sketch that I have been using for testing of all my connections.  Miles Burton talks about this in the code he supplies on his wiki regarding “Dallas Temperature Control Library”.  It can be found here:

http://www.milesburton.com/?title=Dallas_Temperature_Control_Library

Knowing this I went to work to creating a sketch that could read 2 probes.  So here is what I came up with.

/*
Testing Sketch to test 2 temp probes using DS18B20 IC for Stainless Steel probes.
Sketch was created by Miles Burton and changed to
display both C and F temperatures and 2 devices using the serial
monitor for display.

created on 06/01/11
by rik kretzinger   version 2.1
*/

#include <OneWire.h>
#include <DallasTemperature.h>

// Data wire is plugged into pin 8 on the Arduino
#define ONE_WIRE_BUS 8

// Setup a oneWire instance to communicate with any OneWire
// devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);

void setup(void)
{
// start serial port
Serial.begin(9600);
Serial.println(“Dallas Temperature IC Control Library Demo”);

// Start up the library
sensors.begin();
}

void loop(void)
{
// call sensors.requestTemperatures() to issue a global temperature
// request to all devices on the bus
Serial.print(“Requesting temperatures…”);
delay(1000);
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println(“DONE”);
delay(1000);

Serial.print(“111111111111111111111111111111111111111111111111”);
Serial.println();
Serial.print(“Temperature for Probe 002 is:              “);
Serial.print(sensors.getTempCByIndex(0)); // Why “byIndex”? You can have more
// than one IC on the same bus.
// 0 refers to the first IC on the wire.

Serial.println(”  C”);
Serial.print(“FAHRENHEIT CONVERSION                      “);
Serial.print(((sensors.getTempCByIndex(0)*1.8)+32));  // test this line
Serial.println(”  F”);
Serial.println();

Serial.print(“22222222222222222222222222222222222222222222222”);
Serial.println();
Serial.print(“Temperature for Probe 003 is:              “);
Serial.print(sensors.getTempCByIndex(1)); // Why “byIndex”? You can have more
// than one IC on the same bus.
// 0 refers to the first IC on the wire.

Serial.println(”  C”);
Serial.print(“FAHRENHEIT CONVERSION                      “);
Serial.print(((sensors.getTempCByIndex(1)*1.8)+32));  // test this line
Serial.println(”  F”);
Serial.println();
Serial.println();
Serial.print(“END OF TEMP PRBOE READINGS THIS CYCLE”);
Serial.println();

}

I have my probes indexed as P002 and P003.  Knowing this the sketch calls out device (0) first probe (P_002) read and device (1) being the second device (P_003) being read.  So you need to know which is which.  This is because the library starts the device at “0” and build up from there, so the next one read will be “1”, the next one is “2” and so on.  I think you get the idea.

Here are my results from running the above sketch:

2 - Temp Probe readings

10,000 views surpassed on Instructables June 11, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, Crop, DIY aquaponics, DS18B20, Float Sensor, Float Switch, general, Glow Panel 45, Gravity feed valves, Hacks, indoor aquaponics, indoor gardens, indoor growing, Instructables, LED growing, LED lights, plumbing, POW-Rduino, Rj45 connector, sensor, Sensor Hub, Stainless Steel Temp Probe, Standards, sunshine systems, Suppliers, Temperature Probe, Yield Results.
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I have written 3 instructables  over the last 2 years.  I have just gone over 10,000 views.  Never thought I would every have had that many views with only 3 instructions.  Always good to know people are interested in what I am interested in.

Passed 10,000 views

SUGRU – fills in the holes June 7, 2011

Posted by rik94566 in aquaponic automation, aquaponics, CAT 5 Cable, DIY aquaponics, DS18B20, Float Sensor, Float Switch, Hacks, Home Depot, indoor aquaponics, indoor gardens, indoor growing, Rj45 connector, sensor, Sensor Hub, Stainless Steel Temp Probe, Standards, SUGRU, Suppliers, Temperature Probe.
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Now that I have working Sensors on a standardized connection platform (CAT 5 & RJ45).  I need to figure out how to use off the shelf housings that will be plug-n-play for my aquaponic units.  The problem is that nothing is water resistant and they all have lots of openings.  That is because most if not all are for indoor use.  All the outdoor options are to large for my applications.  So I went with a standard indoor 2-Port QuickPort I purchased at Home Depot.

Leviton 2-Port Surface Mount Housing

With a little help from SUGRU I was able to fill in the holes and can now mount the completed unit on my aquatubes.  This will allow me to cover all my sensor connections and transition over to RJ45 connectors.

Here is what I started with:

Starting Housing

Here is what it looked like before assembly:

Openings filled before assembly - Inside look

Bottom View

Here is the completed assembly:

Back View of Completed Assembly

Front View of Completed Assembly

How the openings match-up:

Opening that match-up

Now I am ready to connect up the sensors and mount the completed assembly on the aquatubes hook-up my CAT 5 and I am ready to sense all inputs.  O yes, I need some White SUGRU to make it look better.  I am placing my order today!

RJ45 Sensor Hub June 7, 2011

Posted by rik94566 in aquaponic automation, aquaponics, arduino, CAT 5 Cable, DIY aquaponics, DS18B20, Float Switch, Hacks, indoor aquaponics, indoor gardens, indoor growing, sensor, Sensor Hub, Standards, Temperature Probe.
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2 comments

Now that I have established my standard for sensor connections I will need build the hub to hook up the sensors.  So I build a 2 connector RJ45 jack hub to test the sensors that I build.  This hub will allow me to test different sensor configurations and arduino sketches for test sensors  as I develop them.

Here is what it looks like.

RJ45 Sensor Hub Connector

End view of terminals

I have marked the terminals on both ends so there can be no confusion as to what connections are being used.  Make sure you have test all the connections with your multimeter.  That way you know for sure everything is working before you start testing situations with sensors.