The main system board, just slightly bigger than a business card, is based on a PIC24FJ256 device. A 16-bit MCU running at 32 Mhz . The chip has 256Kb of flash and lots of IO pins and built in peripherals. A 512Kb EE-PROM serves as the permanent storage for the embedded webpages.
The rear side of the board holds a CAT5 connector which is used for the cabling up to the outlaying sensors. The 5 pin white connector on the bottom is for the Baro/Hygro/Temp board. One of the 3 pin connectors is for a 5V power supply feed, and one is a 5V connection for an enclosure fan. The top of the board has connectors for an USB / UART bridge , rain bucket and solar sensor.
Power consumption with the air-data sensors attached is between 0.675 and 0.75 Watt depending on the frequency of WiFi traffic. A complete station with air data and wind sensors, but without an aspiration fan runs on 7/8 of a Watt.
The row of pins extending on both sides allow for two add-on expansion boards.
Since setting up a WiFi based device can be somewhat of a catch 22, a USB/UART COMn device allows for a Windows PC application to setup the WiFi connection parameters in order to bootstrap the WiFi connection. A device driver needs to be installed to recognize the Silicon-Labs USB device. If no PC is available, the system can be configured entirely through it’s web interface, a prescribed procedure needs to be followed and requires you to temporarily set the SSID and encryption of your router to the default values of the station to be configured.