Pages: [1]   Go Down
Author Topic: temperature logger using a solar powered arduino  (Read 2433 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Project: Solar Dryer Temperature profiler

Concept: we are building a low cost solar dryer and wanted to study the temperature profiles during operation. for this purpose, we decided to connect to LM35 temperature sensors to the analog inputs of the arduino. We will write the captured values onto a microSD card so that we can analyze the data later.

We have also decided to make the arduino run on a 12v solar panel with a 9v battery backup. Cicruit diagram is shown below.

Would love to get your feedback and suggestions. Also, we plan to add a computer heat sink fan to the unit that can be controlled through the PWM output of the arduino. but am not sure of how to connect the fan motor to the arduino. inputs will be appreciated!



regards,
Siddharth
Logged

Massachusetts, USA
Offline Offline
Tesla Member
***
Karma: 208
Posts: 8860
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If you run the Arduino at 3.3V and 8 MHz you'll save power so you won't need as large a solar panel or battery.  You will also be able to connect the SD card directly to the Arduino pins without level shifters.  You can use a Micro-to-Standard SD adapter as a Micro-SD socket.
Logged

Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

Santa Fe
Offline Offline
Full Member
***
Karma: 1
Posts: 201
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Why would you need a fan and heat sink? I don't think any of the components get that hot, and it would require a lot more power to drive the fan.

here is a link that you might look at before you go too far. The link also references another link specific to temp logging with the shield.

http://www.planetarduino.org/?cat=343
Logged

Switzerland
Offline Offline
Faraday Member
**
Karma: 108
Posts: 5152
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If you don't insist in building it yourself, here you have most of what you wanna have in one package, optimised to use as low energy as possible:

http://www.seeedstudio.com/depot/seeeduino-stalker-atmega-328-p-600.html

You can directly attach the battery and the solar panel, the necessary charging components are on the board.
Logged

Dallas, Texas
Offline Offline
God Member
*****
Karma: 31
Posts: 887
Old, decrepit curmugeon
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Take a look at the lady ada design; http://ladyada.net/products/usbdcsolarlipo/

She uses a 6V panel, a quasi mppt charging circuit, and a lipo.  The design allows for your circuit to be connected to the charger at the same time as the battery and solar panel.  When the panel is producing an excess of power over powering your circuit, the excess is used to charge the lipo... 
Logged

New true random number library available at: http://code.google.com/p/avr-hardware-random-number-generation/

Current version 1.0.1

Dallas, Texas
Offline Offline
God Member
*****
Karma: 31
Posts: 887
Old, decrepit curmugeon
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Why would you need a fan and heat sink? I don't think any of the components get that hot, and it would require a lot more power to drive the fan.

The fan is not likely for the Arduino circuit, but for the solar dryer function.  I am assuming what he is talking about is something like a solar food dehydrator, where airflow is critical to removing the moisture from the food being dehydrated.  And he probably want to add temperature control to allow the device to maintain the appropriate temperature range for the specific type of food being dried.
Logged

New true random number library available at: http://code.google.com/p/avr-hardware-random-number-generation/

Current version 1.0.1

Santa Fe
Offline Offline
Full Member
***
Karma: 1
Posts: 201
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If that is the case he will probably need something a little more beefy than a heat sink fan, unless it is a pretty small dryer. A convection stack might work better and requires no power.

http://solarcooking.wikia.com/wiki/Solar_food_drying
« Last Edit: July 30, 2012, 10:43:02 am by RPCoyle » Logged

Dallas, Texas
Offline Offline
God Member
*****
Karma: 31
Posts: 887
Old, decrepit curmugeon
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

If that is the case he will probably need something a little more beefy than a heat sink fan, unless it is a pretty small dryer. A convection stack might work better and requires no power.

http://solarcooking.wikia.com/wiki/Solar_food_drying


I don't think so, I have an excaliber food dehydrator on my counter and the fan on it looks very much like a standard PC case fan.
Logged

New true random number library available at: http://code.google.com/p/avr-hardware-random-number-generation/

Current version 1.0.1

Santa Fe
Offline Offline
Full Member
***
Karma: 1
Posts: 201
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I don't think so, I have an excaliber food dehydrator on my counter and the fan on it looks very much like a standard PC case fan.

Probably true... but it sounds like  strangeloop is talking about a bigger unit otherwise it would be kind of an overkill to have four temperature sensors in something you could put on your counter. Since it is solar, I still think it is a good idea to look into convection airflow. That way the only thing consuming power would be the data logger.
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Why would you need a fan and heat sink? I don't think any of the components get that hot, and it would require a lot more power to drive the fan.

here is a link that you might look at before you go too far. The link also references another link specific to temp logging with the shield.

http://www.planetarduino.org/?cat=343


We are using the fan to facilitate air movement along the solar dryer column.
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If that is the case he will probably need something a little more beefy than a heat sink fan, unless it is a pretty small dryer. A convection stack might work better and requires no power.

http://solarcooking.wikia.com/wiki/Solar_food_drying


Thanks.. will have a look at this idea as well.
Logged

Pages: [1]   Go Up
Jump to: