bh. Modular Weather Station Project (v1.0 and v2.0)

MODULAR CONCEPT: Click on the schematic to enlarge it

Each measurement unit has a wireless transceiver and a number of sensors. The sensors values are transferred on demand to the base station. The later relies on round robin polling model to collect data from all the measurements units in real time. The data is also available on a PC via USB connection.

There are a number of (home) weather stations on the World's consumer electronics market, but none supports as much functionality as PC USB Projects Modular Weather Station. The weather station is based on a modular concept, which allows one to connect as many wireless external measurement units as needed to the base station that doubles as a hub and has a USB connection to (home) control center or a home PC.

Windows Weather Station application communicaters to a PC via USB 2.0.

BASE STATION DATA DISPLAYED ON GLCD: Click on the photo to enlarge it.

There are three kinds of sensors supported on measurements units: temperature sensors (Advance Devices ADT7410), air pressure sensors and temperature sensors (HopeRF HP03MA) and humidity and temperature sensors (HopeRF TH02).

Modular Weather Station is a developing project. Currently a new BASE STATION v2.0 is available together with PIC32MX270F256B firmware v3.0.0. The software examples and applications available from Downloads section support PIC18 and PIC32 based base stations. They cover various Weather Station hardware functionalities, but not necessarily all of them. Occasionally all the functionalities will be covered as the software is fully developed. All the application software source code is also published on PC USB Projects Downloads section.

NOTE 1: Time and date can be set and displayed on the weather station by PIC18F2xJ50 Digital Clock with LCD application.

NOTE 2: You have to program the appropriate firmware to your microcontroller before you use Weather Station control application. The firmware is available from Downloads section.

Gathering data from remote units is currently supported by a different sample application (Digital thermometer and thermostat (ADT7410) v9 x64 with RFM69CW SPI connection example.zip), but will be soon integrated.

Weather Station control application example v2.6 Weather Station v2.6 x64.zip is still available to demonstrate a way for immediate access to senosors. In fact it enables a PC to gather current temperature, air pressure and humidity values in real time.

Alternatively, you can use PIC.WeatherStationGetRawData() function and make calculations yourself. Both options are included in v3.0 example.

PIC.WeatherStationGetData()

temperature_from_air_pressure_sensor_as_single = PIC.ReadBufferSingle(0)

air_pressure_as_single = PIC.ReadBufferSingle(4)

temperature_from_humidity_sensor_as_single = PIC.ReadBufferSingle(8)

humidity_as_single = PIC.ReadBufferSingle(12)

The current version of Weather Station control application (v3.0) supports all the sensors attached to the base station (Weather Station v3.0 (x64).zip) and remote mearurement units sensors access. The v3.0 example reads buffered sensor values or final temperature, humidity and air pressure values calculated by PIC18F26J50 or PIC32MX270F256B. Now, it is really easy to read the current values into a PC:

BASE STATION v2.0 (PIC32MX270F256B) with the external I2C bus connector: Click on the schematic to enlarge it.

BASE STATION v1.0 (PIC18F26J50) with the external I2C bus connector: Click on the schematic to enlarge it.

NOTE 6: Quality and version of HopeRF RFM69CW transceiver modules are important! A bad module may not be able to reliably communicate to all the other modules. It is though advisable to buy all the modules for the base station and RMUs from the same suppler in a single purchase. If you are buying additional modules later, purchase high quality modules. It is also highly unadvisable to intermix RFM69CW modules that are adapted for different frequencies. A module carrier frequency may be changed programmatically, but it may still perform poorly at non native carrier frequencies.

NOTE 5: Weather information can be displayed on the LCD (see the base station schematic) and the GLCD at the same time, but you may skip implementation of the LCD, if you implement GLCD. It is easy! You just connect the GLCD to I2C bus and you leave LCD pins on PIC18F26J50 unconnected.

NOTE 4: RMU AND THERMOSTAT FIRMWARE: Use PIC32MX270F256 firmware v2.8.81 for all RMUs.

NOTE 3: BASE STATION FIRMWARE: If PIC18F26J50 firmware v2.8 and PIC32MX270F256 firmware v3.0.0 are configured for weather base station operation, the starts displaying room temperature, air pressure and humidity automatically immediately after the weather station is plugged in a USB port, or powered by a USB charger. PIC18F26J50 firmware v2.8.1 and PIC32MX270F256 firmware v3.1.0 (external GLCD only support) also support the external GLCD whitch offers much more space for displaying data.

REMOTE MEASUREMENT UNIT (RMU or SENSOR UNIT) WITH THERMOSTAT: Click on the schematic to enlarge it.

SIMPLE REMOTE MEASUREMENT UNIT (RMU or SENSOR UNIT) WITH UP TO TWO ADT7410 SENSORS: Click on the shematic to enlarge it.