Herb and Barbara - our interests and family

Micro Energy System Upgrades—Rev 2.1

The current system is at revision level two (2.0) and with the addition of the temperature sensor, is now at 2.1.

Using  the Arduino micro-computer as the brains of the monitoring and charging system affords me the ability to easily upgrade the system and add new features without the need for tedious circuit board wiring. The addition of a temperature sensor took about 45 minutes to install (no I did not include the time to write the software) and now gives Marie the ability to check and record the temperature about two inches off the ground.

The sensor is an LM-35 from National Semiconductor and is a less than $2.00 part. It has a  linear output scale which makes it very easy to calibrate. (Linear + 10.0 mV/°C scale factor ) .

 

Translated—to calibrate the unit is software requires that you measure the output, using a DVM with a 300 millivolt scale, divide that number by 10 and you have the temperature in Celsius.

 

I mounted the sensor in a piece of PVC and connected it to the Arduino using shielded, twisted pair wire. This is very important as the a wire run of more then a few inches will generate noise that the A to D converter on the Arduino will interpret as a temperature swing.

 

I put a .01 uF cap across the output to ground on the sensor and an additional 25Mf cap as the connecting cable entered the box where the Arduino is located.

The turbine is again flying and will have the prop mounting plate replaced when the new one arrives from Wind Stuff Now.

 

The garden is also growing nicely. The photograph to the left shows Swiss Chard and the irrigation tape.

 

Pumping water through this irrigation tape is what the Micro Renewable Energy System was designed to do. I installed radio telemetry and the Arduino micro-computer to collect information on wind and solar system performance in real world applications. With this system I am able to document how well improvements perform and demonstrate that it is not always necessary to spend a great deal of money to have a small working system.

 

One of the goals of the farm is help others who want to start small CSA farms. The renewable energy system is one of the ways to cut start up costs.