Vermes
Advanced Member level 4
The main element of the weather register system is Atmega32. The system was written in BASCOM. It takes 42%.
Measurements are made on 3 sensors:
- internal temperature and humidity: SHT10
- external temperature: DS18B20
- atmospheric pressure: MPX4115
The results of measurements are written on SD card into TXT files each time when the minutes are 0, 10, 20, 30, 40 or 50. The measurement is taken each 15 seconds and the current one is displayed on LCD.
Additionally, the system has automatic regulation of the lightness of the display. The purpose is the display doesn't strike on nightlight and is easy to be read on daylight. The measurement of lightness is taken by resistive diviner made of photoresistor and resistor 100kohm. A correction of each PWM signal is made programatically. The correction of lightness is repeated each 25 second of every minute. This frequency of checking helps to prevent the back-light from irritating blinking.
The system is maintenance. There are two switches to set the date and hour in PCF8583 system and two LEDs to signalization of communication with PCF8583 (the green one) and to save the data on SD (the red one). Any problems with saving on SD card are signalized by viewing the full icon of card on the display and continuous LED light. Under normal circumstances, the red LED is out and the card symbol is empty.
As a housing, a piece of plexi bended with a hot air was used.
Way of saving measurements on SD card:
Presentation of results in a spreadsheet:
Link to the original thread where you find useful attachments also - Rejestrator pogodowy