Multipurpose Weather Station

Overview

A PIC18F452 microcontroller is the basis of the project as it runs at 4MHz while displaying auto-memory in all high and low values without any predicament.

Explanation

This weather station is capable of several tasks including reading the pressure, relative humidity, indoor & remote outdoor temperature display. The units of measurement can be Fahrenheit or Celsius and mbar/hPa or mmHg. It also features an easy 3-button user menu, power saving sleep mode, 42-hour history display curve, and calendar & clock. The sensors on this device can be turned ON when needed thereby reducing consumption.

A small 9V battery can be used to power the circuit but a couple of AA batteries can be used. For several months of use, a 6-pack is advisable since the consumption for the base station is about 8-9mA when active  and 2-3mA only when in sleep mode but the LCD remains ON. Less consumption is being taken by the transmitter which takes a nap every 30 seconds or more. Every 5 seconds, the receiver or base station is active then goes to sleep for 45 seconds.

The most expensive part is the MPX4115A pressure sensor along with TC77 SPI temperature sensor.