Solar Power for the Pi/Arduino – Six Days In The Sun

October 17, 2014 Arduino, Arduino Software, MouseAir, Pi Camera, Project Curacao, Python Raspberry Pi Software, Raspberry Pi, RasPiConnect, Real Time Clocks, Solar Power, SwitchDoc Dual WatchDog Timer, WeatherPiArduino
Solar Power
Raspberry Pi Power Subsystem

Solar Power for the Pi/Arduino – Six Days In The Sun

Last week the full set of upgrades were applied to the Project Curacao project down in the Caribbean.   I added the following:

  • New Wind Turbine
  • Hardware WatchDog Timer (the SwitchDoc Dual WatchDog timer) added for reliability
  • Weather Station – Wind direction, wind speed and Rain using WeatherArduino
  • FRAM storage on Battery Watchdog Arduino on WeatherArduino Board for night time log storage when the Raspberry Pi is off
  • New Solar Panels – one for the Raspberry Pi and one for the Battery Watchdog Arduino
  • New Real Time Clock – DS3231 on the WeatherPiArduino board

I have been monitoring the system in the Caribbean (I am now back in the Pacific Northwest – 3500 miles away from the Box) closely using my RasPiConnect control panels and Matplotlib graphs displayed by RasPiConnect.  After six full days in the hot sun, I am pleased to report good news.  Both the Raspberry Pi and the Arduino Battery Watchdog are fully charging each day.  Even in the cloudy skies of the rainy season on Curacao.

Here is the Raspberry Pi Power subsystem RasPiConnect screen:

Solar Power
Raspberry Pi Power Subsystem

The graph shows that the Raspberry Pi batteries are being fully charged every day.  You can tell that because the Solar Power voltage goes above 5V during the middle of each day. Note that when this graph was taken, it was 5:30PM (17:30) and the sun was getting low in the sky and there wasn’t very much solar power coming in (0.7W).  The latest picture from the Project Curacao Pi Camera system is shown below.

Pi Camera
The Caribbean at 17:30 in the Evening

 

The Arduino Battery WatchDog

The Arduino Battery WatchDog is in equally good shape.  The additional solar panel is keeping the battery charged, even during the rainy season.  The RasPiConnect screen for the Arduino Battery WatchDog power subsystem is below.

IMG_0752

You can see that the Arduino’s batteries are charged up early in each day (look at the Solar Power Voltage peaks above 5V on the graph above).  Excellent results.  This new solar panel and the WatchDog DeadMan hardware timer will dramatically improve the reliability of the Battery WatchDog. You can buy the WatchDog board here.  The Reliability will also improve with the removal of the evil DS1307 RTC and the replacement with the DS3231 RTC.

More Reliablity. More Reliablity. More Reliability.

The initial design of Project Curacao required the Arduino to be on 24/7 every day and never quit.  That turned out to be a problem as the Arduino would run out of battery power every 8 weeks or so (the Solar didn’t QUITE keep up) and worse yet, the flaky DS1307 would hang the Arduino about every 4 weeks.   So much for reliability.   I fixed this by

DS1307
Removing the Evil DS1307 RTC from the Arduino

adding the SwitchDoc Labs Dual Watchdog hardware timer to reboot the Arduino if it stops “patting the dog” every 60 seconds.  I also replaced the DS1307 (by literally ripping out the DS1307 with my hand by removing the Evil DS1307 RTC from the Arduino by flexing the pins until the broke off via metal fatigue – it had to go because it shared the I2C addresses of the replacement DS3231 – even with the DS1307 battery pulled out).  I put the new DS3231 on the WeatherArduino board I2C socket.

DS3231
DS3231 on WeatherArduino Board (right and upside down)

 

 

 

 

 

 

 

Wind Power for The Pi and Arduino

New data is flowing into the MySQL database on the Raspberry Pi on the wind speed, currents, etc.  More on the Wind Power System next week.