Data Logger for a Solar System

[[email protected]]

Hi Everybody,

I am looking for a data logger which collects data from my "Solar remote site".
I can visit these sites every 4 to 6 months for maintenance and need to collect data on a memory card or on the internal memory of the device in orderto download them. Better will be if I could get the data over internet on my laptop as I have mobile coverage on Site (but this is not really mandatory).

The data logger should measure and collect following data every 15 or 30 or60 minutes:
- Date & time
- Current: between “0 A” up to “250A” (4 X DC channels in order to be able to measure different sources)
- Voltage: between “0 VDC” up to “60 VDC”
- Temperatures: between “-5°C” up to “55°C” (3 or 4 channels inorder to measure outside, inside, battery temp)

I need also all related sensor. Could anybody support me?

BR,
Amir

 

[Jim Wilkins]

You need a microprocessor to handle the data collection and writing
to probably an SD card to save the data. There are a couple of
options.

PICAXE - developed for education in the UK; programmed in a version
of BASIC; free software available for Windows, OSx, and Linux; has a
very active user forum:
www.picaxeforum.co.uk/forumdisplay.php?2-Active-PICAXE-Forum?

Arduino - very popular; programmed in C (not always easy for a
beginner); many parts available at Radio Shack; lots of support
sites including some projects on instructables.com;
Various sensors available from sparkfun.com although AMP makes some
excellent Hall effect current sensors in various ranges from 25 amps
and up

Both PICAXE and Arduino can monitor voltage via built-in ADC ports.
Both can read temperature using the DS18B20 one-wire temperature
chip.

Arduino C is relatively simple to learn and easy to use. The program
memory in the chip does wear out from too many Writes, though, like a
Solid State Drive.

Here is another isolated current sensor supplier:
http://www.gmw.com/magnetic_sensors/asahi/current-sensors-HA.html

Shunts require very careful design to avoid common-mode interactions
on the sense leads.
http://www.amazon.com/dp/B006Z954QA
Every wire and connection is a resistor that creates a voltage drop.
Yesterday I measured 350mV of drop between the elements of my TV
antenna with only 1A passing between them. Wiggling the rivet joints
while the current flowed reduced that to 20mV, and I gained almost
10dBm of signal strength.

http://www.dataq.com/?source=googledq&gclid=CODez8y1kasCFesLtAodJS-Qtg
Three separate EL-USB loggers may be the simplest and cheapest
approach if you can tolerate unsynchronized readings.

If your electronic technician skill level isn't up to building safe
and reliable circuits from scratch you might consider an old laptop
and a USB DAQ. My Compaq Armada consumes as little as 7W at idle with
the screen off, and can operate from an external 12V battery with the
Auto-Air adapter. Spare batteries are fairly inexpensive for some
common laptops like Dell Latitudes. It needs only a few minutes of
remaining run time to move between chargers.

A quick search for wake timers found:
http://www.raymond.cc/blog/automatically-wake-up-from-windows-stand-by-and-hibernation/

http://www.techrepublic.com/article/automatically-wake-a-hibernating-windows-xp-machine/

jsw

 

[j]

On 7/27/2013 9:09 AM, [email protected] wrote:> Hi Everybody,

I am looking for a data logger which collects data from my "Solar

remote site".

If you go Arduino you can get an SD card/ethernet shield combo. There
are a huge number of available shields including cellphone. Arduino has
limited memory and interface capacity without a "shield".

Arduinos have A/D's for data logging and there are "1 wire" temp sensors
that connect to the digital inputs.

http://www.arduino.cc/

Arduino is easy out of the box:

http://www.ladyada.net/learn/arduino/index.html

It's not the only micro controller out there. But it is widely available
and cheap. You can find "sketches" of data logging and one wire temp
reading that can be altered to suit fairly easily. The learning curve is
easy.

Also available are Raspberry Pi's and Beagle Bone Blacks. Both run Linux
and can be programmed in almost any language. Both also have analog and
digital inputs and outputs similar to the Arduino but are also full
fledged mini computers.

Jeff

I can visit these sites every 4 to 6 months for maintenance and need

to collect data on a memory card or on the internal memory of the device
in order to download them. Better will be if I could get the data over
internet on my laptop as I have mobile coverage on Site (but this is not
really mandatory).

The data logger should measure and collect following data every 15 or 30 or 60 minutes:
- Date & time
- Current: between “0 A” up to “250A” (4 X DC channels in order to be

able to measure different sources)

- Voltage: between “0 VDC” up to “60 VDC”
- Temperatures: between “-5°C” up to “55°C” (3 or 4 channels in order

to measure outside, inside, battery temp)

 

[Neon John]

On 7/27/2013 9:09 AM, [email protected] wrote:> Hi Everybody,
remote site".

If you go Arduino you can get an SD card/ethernet shield combo. There
are a huge number of available shields including cellphone. Arduino has
limited memory and interface capacity without a "shield".

Arduinos have A/D's for data logging and there are "1 wire" temp sensors
that connect to the digital inputs.

This kind of advice invariable comes from someone who's never actually
done it before. As someone who designs this stuff for a living, let's
examine that advice a bit more.

It's true that the Arduino has 8 12 bit A/D converters of the
successive approximation type. But there's more.

* Typically there are 3-4 bits of noise on the converters and/or
reference voltage so 8 bit data is the best that one can RELIABLY get.

* The input is 0-2.54 volts (unless one hacks in his own voltage
reference which brings in its own set of problems.

* The processor starts executing spurious instructions when the input
voltage reached about 2.6 or 2.7 volts.

* that channel is blown when the input reaches 3 volts.

* It has practically no static or transient protection.

* The input impedance varies during the successive approximation so
the input must be driven by a low impedance source (op amp or
instrument amp).

* the input is monopolar. Bipolar (AC) inputs make the processor very
unhappy.

The field signal for each channel must be scaled or amplified as
needed, zero offset, filtered, shaped, perhaps rectified and
conditioned for each input port. This will cost many more dollars
than the Arduino itself and will require a vast amount of time to get
right. Much more money, in fact, than simply buying the proper data
logger to fit the application.

The correct answer to the OP's question should be another question,
"What kind of physical data are you trying to capture? Most likely
volts and amps. What else? Thermocouple input? Sunlight intensity?
Ambient temperature? What range of temperature operation to you
require?

All that has to be known before any meaningful advice can be given.

John
John DeArmond
http://www.neon-john.com
http://www.fluxeon.com
Tellico Plains, Occupied TN
See website for email address

 

[Neon John]

Hi Everybody,

I am looking for a data logger which collects data from my "Solar remote site".
I can visit these sites every 4 to 6 months for maintenance and need to collect data on a memory card or on the internal memory of the device in order to download them. Better will be if I could get the data over internet on my laptop as I have mobile coverage on Site (but this is not really mandatory).

The data logger should measure and collect following data every 15 or 30 or 60 minutes:
- Date & time
- Current: between “0 A” up to “250A” (4 X DC channels in order to be able to measure different sources)
- Voltage: between “0 VDC” up to “60 VDC”
- Temperatures: between “-5°C” up to “55°C” (3 or 4 channels in order to measure outside, inside, battery temp)

With what you've specified, you need 9 channels. That would push you
into the expensive world of 16 channel data loggers. If you drop a
temperature channel (you really don't need battery temperature) then a
much less expensive data logger can be used.

We need some more data before any hard recommendations can be made.
For instance. do the inputs have to be isolated? That is, do they
need separate grounds? If so that pushes the cost up significantly.

If you can arrange your circuitry so that all inputs share a common
ground then you can use a relatively inexpensive common ground system.

Here's a typical relatively low cost unit.

http://www.omega.com/pptst/OM-CP-OCTPROCESS.html

8 channel, current input, lithium battery powered, data collected via
a PC. Enough memory to do 16 samples per hour for 6 months (if I did
my math correctly).

Most any variable can be easily converted into a current with low
noise. That's why 4-20 ma is so common in industry.

In this case, a simple series resistor would convert the 60 volts to
say 1 ma. For current, either a shunt or a hall effect device
measures the current and its output is converted to a current with a
simple resistor.

For temperature you can go simple and use a thermistor scaled and
linearized to output a current. This device allows one to store
per-channel scaling factors so the actual value doesn't matter much.

Or you could go a bit more complicated and use an LM35 temperature to
voltage IC

http://www.ti.com/product/lm35

The voltage output is again converted to current with a resistor. This
(and the thermistor, for that matter) will require a small amount of
power. You can rob that from the 60 volt input using a zener diode in
parallel with the LM35 to keep the supply voltage stable..

The LM35 draws worst case 136uA and needs from 5 to 15 volts to
operate. I'd choose 15 volts to get the maximum range. The resistor
is 60-15 = 45 volts /136uA = 330kohms. That would dissipate 6 watts.
If your typical supply voltage is different than 60 volts then just
substitute the numbers.

This post isn't designed to answer your question directly. It's
designed to get you thinking in the right direction. If you google
"battery powered 8 channel data logger", you'll find hundreds of
varieties. The Omega one was simply one of the first hits.

John
John DeArmond
http://www.neon-john.com
http://www.fluxeon.com
Tellico Plains, Occupied TN
See website for email address

 

[Jim Wilkins]

...>
It's true that the Arduino has 8 12 bit A/D converters of the
successive approximation type. But there's more.

* Typically there are 3-4 bits of noise on the converters and/or
reference voltage so 8 bit data is the best that one can RELIABLY
get.

John
John DeArmond

What do you suggest as an alternative?

I just discovered BatteryInfoView from NirSoft for logging the battery
discharge on a laptop too old to have sensors that HWiNFO32
recognizes. Some of his other programs like Produkey dig deep enough
to trigger antivirus warnings.
http://www.nirsoft.net/

Several full discharge and recharge cycles have restored the capacity
of the original battery in my 1999 Compaq from a few minutes to about
an hour.
jsw.

 

[Martin Riddle]

With what you've specified, you need 9 channels. That would push you
into the expensive world of 16 channel data loggers. If you drop a
temperature channel (you really don't need battery temperature) then a
much less expensive data logger can be used.

We need some more data before any hard recommendations can be made.
For instance. do the inputs have to be isolated? That is, do they
need separate grounds? If so that pushes the cost up significantly.

If you can arrange your circuitry so that all inputs share a common
ground then you can use a relatively inexpensive common ground system.

Here's a typical relatively low cost unit.

http://www.omega.com/pptst/OM-CP-OCTPROCESS.html

8 channel, current input, lithium battery powered, data collected via
a PC. Enough memory to do 16 samples per hour for 6 months (if I did
my math correctly).

Most any variable can be easily converted into a current with low
noise. That's why 4-20 ma is so common in industry.

In this case, a simple series resistor would convert the 60 volts to
say 1 ma. For current, either a shunt or a hall effect device
measures the current and its output is converted to a current with a
simple resistor.

For temperature you can go simple and use a thermistor scaled and
linearized to output a current. This device allows one to store
per-channel scaling factors so the actual value doesn't matter much.

Or you could go a bit more complicated and use an LM35 temperature to
voltage IC

http://www.ti.com/product/lm35

The voltage output is again converted to current with a resistor. This
(and the thermistor, for that matter) will require a small amount of
power. You can rob that from the 60 volt input using a zener diode in
parallel with the LM35 to keep the supply voltage stable..

The LM35 draws worst case 136uA and needs from 5 to 15 volts to
operate. I'd choose 15 volts to get the maximum range. The resistor
is 60-15 = 45 volts /136uA = 330kohms. That would dissipate 6 watts.
If your typical supply voltage is different than 60 volts then just
substitute the numbers.

This post isn't designed to answer your question directly. It's
designed to get you thinking in the right direction. If you google
"battery powered 8 channel data logger", you'll find hundreds of
varieties. The Omega one was simply one of the first hits.

John
John DeArmond
http://www.neon-john.com
http://www.fluxeon.com
Tellico Plains, Occupied TN
See website for email address

Labjack looks good too. I havent personally used them, but I've heard
good things...
<http://labjack.com/>

Cheers

 

[Mr Clarke]

Labjack looks good too. I havent personally used them, but I've heard
good things...
<http://labjack.com/>

Cheers

You make it and I`ll make a better one and sell millions of them!

 

[Jim Wilkins]

Labjack looks good too. I havent personally used them, but I've
heard
good things...
<http://labjack.com/>

Cheers

Thanks. The U3 looks interesting.
jsw

 

[Martin Riddle]

Thanks. The U3 looks interesting.
jsw

Just a note:

FW Bell Current sensors....
<http://www.alliedelec.com/sensors-switches-relays/sensors/?dsNav=N:4294886853-4294811111>

In case that was a search session <http://www.alliedelec.com/fw-bell/>


Cheers

 

[No Body]

This kind of advice invariable comes from someone who's never actually
done it before. As someone who designs this stuff for a living, let's
examine that advice a bit more.

It's true that the Arduino has 8 12 bit A/D converters of the
successive approximation type. But there's more.

* Typically there are 3-4 bits of noise on the converters and/or
reference voltage so 8 bit data is the best that one can RELIABLY get.

* The input is 0-2.54 volts (unless one hacks in his own voltage
reference which brings in its own set of problems.

* The processor starts executing spurious instructions when the input
voltage reached about 2.6 or 2.7 volts.

* that channel is blown when the input reaches 3 volts.

* It has practically no static or transient protection.

* The input impedance varies during the successive approximation so
the input must be driven by a low impedance source (op amp or
instrument amp).

* the input is monopolar. Bipolar (AC) inputs make the processor very
unhappy.

The field signal for each channel must be scaled or amplified as
needed, zero offset, filtered, shaped, perhaps rectified and
conditioned for each input port. This will cost many more dollars
than the Arduino itself and will require a vast amount of time to get
right. Much more money, in fact, than simply buying the proper data
logger to fit the application.

The correct answer to the OP's question should be another question,
"What kind of physical data are you trying to capture? Most likely
volts and amps. What else? Thermocouple input? Sunlight intensity?
Ambient temperature? What range of temperature operation to you
require?

All that has to be known before any meaningful advice can be given.

John
John DeArmond
http://www.neon-john.com
http://www.fluxeon.com
Tellico Plains, Occupied TN
See website for email address

John...

Some of the concernes you raise are addressed by this system:

<https://shop.ruggedcircuits.com/index.php?main_page=product_info&products_id=23>


I will often used Dallas/Maxim One-wire devices, if the temps are in a
range that they will deal with..

Then again.. a data logger for an entire Solar System.. That's one big
honkin machine!

 

[Jim Wilkins]

Some of the concernes you raise are addressed by this system:

<https://shop.ruggedcircuits.com/index.php?main_page=product_info&products_id=23>


I will often used Dallas/Maxim One-wire devices, if the temps are in
a
range that they will deal with..

Then again.. a data logger for an entire Solar System.. That's one
big
honkin machine!

Neon John's comments seem to apply more to a LabJack than an Arduino.
http://labjack.com/u3

I've been using an older Radio Shack PC-interfaced multimeter to log
solar panel output. It's only one slow channel, but it's opto-isolated
for safety and ground-loop immunity and can read AC or DC voltage and
current, up to 20A. The newer model also reads temperature. There are
several less expensive versions on-line.

This decodes the serial data stream:
http://www.franksteinberg.de/SOURCE/DT9062.BAS

and here are the bit assignments in English:
http://www.multimeterwarehouse.com/TP4000ZC/TP4000ZC_serial_protocol.pdf

I've ordered one of the cheaper ones to see if I can put together a
3-channel laptop datalogger using the included software or a Basic
program and a Cardbus dual serial port.

When I was building electric vehicles I used a Campbell Scientific
datalogger to record test runs.
http://www.campbellsci.com/

jsw

 

[Jim Wilkins]

I've ordered one of the cheaper ones to see if I can put together a
3-channel laptop datalogger using the included software or a Basic
program and a Cardbus dual serial port.

jsw

Scratch off the clunky included software which is for one meter only.
My QBasic test code that reads the older RS meter runs slowly in XP,
so this will be a DOS project, maybe using the two multimeters as
opto-isolated current sensors and my DI-194RS datalogger for DC
voltages.
http://www.dataq.com/products/obsolete/di194.html

Windows 7 includes a 6.22-style DOS that handles NTFS and long
filenames. I found it while exploring POWERCFG options and piped the

HELP output to a file to start a manual for it.

jsw

 

[[email protected]]

Hi Everybody,



I am looking for a data logger which collects data from my "Solar remote site".

I can visit these sites every 4 to 6 months for maintenance and need to collect data on a memory card or on the internal memory of the device in order to download them. Better will be if I could get the data over internet on my laptop as I have mobile coverage on Site (but this is not really mandatory).



The data logger should measure and collect following data every 15 or 30 or 60 minutes:

- Date & time

- Current: between “0 A” up to “250A” (4 X DC channels in order to be able to measure different sources)

- Voltage: between “0 VDC” up to “60 VDC”

- Temperatures: between “-5°C” up to “55°C” (3 or 4 channels in order to measure outside, inside, battery temp)



I need also all related sensor. Could anybody support me?



BR,

Amir

[deleted]

https://docs.google.com/document/d/...2evhKNDPldk/edit?usp=sharing&authkey=CKuE3KoF



Dinnnnnng ... they are ready, Joe ...

All matter is simply energy condensed into a slow vibration. We are all one conscientiousness experiencing itself subjectively. There is no such thing as death. Life is a dream and we are the imagination of ourselves.

I like to think that if anything made it past the big bangs, black holes and "over the rainbow".. to create life, it was the life force of all life throughout the Universe... the place we all go back to, no matter where we come from.

I don't think I'm in Kansas anymore. Money is simply the devils sex tools without Viagra.

WOMP WOMP

Tom

 

[Bob F]

On Saturday, September 21, 2013 6:41:10 PM UTC-7, Hägar wrote:

All matter is simply energy condensed into a slow vibration. We are
all one conscientiousness experiencing itself subjectively. There is
no such thing as death. Life is a dream and we are the imagination of
ourselves.

I like to think that if anything made it past the big bangs, black
holes and "over the rainbow".. to create life, it was the life force
of all life throughout the Universe... the place we all go back to,
no matter where we come from.

I don't think I'm in Kansas anymore. Money is simply the devils sex
tools without Viagra.

You had to include interminable SPAM to say THIS????