Solar Power – Project Curacao Update

Project Curacao is back from the Caribbean and is back in the Frozen

North(tm).

Project Curacao is a solar powered sensor filled project designed to hang on a radio tower on the island nation of Curacao. Curacao is a desert island 12 degrees north of the equator in the Caribbean. It is a harsh environment with strong tropical sun, salt spray from the ocean and unremitting heat. But it is a beautiful place to visit and a real challenge to build and install a Raspberry Pi based environmental monitoring system.

Want to build your own Solar Power System?  Check out the SunAir Solar Controller.

Project Curacao consists of four subsystems. A Raspberry Pi Model A is the brains and the overall controller. The

Power Subsystem consists of LiPo batteries and charge management. The Environment Sensor Subsystem has in-box temperature, outside temperature, luminosity, barometric pressure and humidity sensors. The Raspberry Pi Camera Subsystem contains a Raspberry Pi Camera and a servo motor controlling the cap (made from a Kitty Litter Container!) over the camera to keep salt spray off the camera lens.

It quit back on November 23, 2014 during a ham radio contest that was barraging Project Curacao with RFI (Radio Frequency Interference).   We expected from the data in late November that the front end of the Arduino processors was ruined by the RF interference during a late November 2014 Ham Radio Contest (not their fault – we should have put a choke on the long sensor lines headed to the WeatherRack weather sensors – which we will do before we send the box back down to the tropics.  Basically,  the RFI caused the Arduino to reboot periodically during the weekend before during another radio contest, but recovered.  However during the next weekend, it now looks like that the Raspberry Pi SD Card was corrupted, possibly by too many reboots because of the RF issues.

When we got the box back in our lab and opened it up, the interior looked very clean and the solar cells were perfect (thank you Voltaicsystems.com).  However, the batteries had not been removed before shipment.  The mounts were never designed for transport and the batteries came off the velcro strips and flopped around pulling wires off and generally causing issues.  This damage was not hard to fix.

 

 

 

 

The SwitchDoc Labs Dual WatchDog Timer and the WeatherPiArduino board were in great shape.  First thing we did was replace the PiCamera mount.  In the picture to the left, you can see the

improvement in our technology from the old mount to the new 3D printed mount.  How things have changed in the year the project was in the Caribbean.

Next, the batteries were reinstalled and some additional wires were repaired.  The two sensors that failed during last summer (the DHT-22 internal humidity sensor and the outside AM2315 I2C Humidity sensor – we baked the humidity sensor in the direct sun for two months, which killed the humidity sensor).  Both of these sensors are being replaced.  The rest of the project is in good shape.

We plan to ship it back to Curacao in late March.  For testing we have it outside in the back of a house nearby and it is suffering through below freezing temperatures.  We are seeing significant A/D issues from the Arduino in the colder temperatures.  30% error in voltage measurements.  We will have to investigate this phenomena.