The previous photo shows a view of the Western vista, this data is updated hourly (when connected) and shows sensor data collected from the Southern vista.
The image shows sensor data for the Current flowing into the 12V Deep Cycle battery through the SunForce 7Amp charge controller as detected by the Allegro 5B ACS712 Sensor, the luminescence detected by the Ambient Light Sensor, and the Temperature as measured by a MCP9700 Temperature Sensor. The error bars show the limit of accuracy for each measurement.
Error margins are based on the datasheet values of the current sensor and the temperature sensor. The light sensor error margins are based on the common belief that direct sunlight is from 32,000 to 100,000 lux. The maximum sunlight measurement the sensor provides is set at 66,000 lux and errors are adjusted accordingly. There has been no calibration of the light sensor and its datasheet gives no margin of error for any reading.
The Current is sometimes not flowing during Sunlit conditions when the battery is fully charged as the charge controller is designed to do. Some outliers may be caused by radio transmission errors that were undetected by the cyclic redundancy check algorithm.
The sensors are connected to a remote computer through wires. Data is transmitted back through the remote computer to the local computer at 315MHz. Some radio interference causes erroneous dates and times in the transmissions/receptions, so these values are elimated from the data based on their validity. Also eliminated, presumably for the same reason, are charging Amperes greater than 4.5 A and less than 0 A (a light sensitive relay elminates back currents), as well as illuminance values greater than 200,000 lux.
July 12, 2015