Bob Harbour Taps Industrial Design for This Slick Two-Box Weather Station
Having been disappointed with commercial offerings, Harbour set about building his own weather station with an industrial twist.
Electrical engineer Bob Harbour has built a two-box solution to the problem of logging detailed weather information and displaying it without having to pull out a smartphone or fire up a PC — and it's powered by a pair of Microchip SAM D21 microcontrollers.
"Being able to measure and record outdoor weather data is something that I have wanted to do for quite a while," Harbour explains. "Initially, I thought about building a "headless" system that would just record the data to my PC. After thinking about it more, I decided that displaying the data without having to power up the PC would be nice. This grew into the idea of a small indoor display and an outdoor sensor box."
Harbour already had experience with building display systems around dot-matrix LED display modules, including an indoor weather display — but his previous efforts were a little too bulky and obtrusive, leading to the decision to design a new version on a smaller scale. Powered by a Microchip SAM D21 microcontroller, the display unit connects to a sensor unit positioned outdoors using RS422 over a run of CAT5 network cable handily already run to a suitable spot.
"The Remote Sensor Box interface board has an RS422 transceiver chip, a clock/calendar chip with battery backup, and connectors," Harbour explains. "The RJ45 connector is a 'Rugged' [design] with IP68 rated sealing to keep moisture out of the sensor box. On the mounting face of the connector, an O ring seals the face to the inside of the sensor box to complete the seal."
A sensor board, fitted with an NXP barometric pressure and temperature sensor and a Honeywell temperature and humidity sensor, feeds weather data into the remote sensor box that handles all the calculations required — part of an original plan to run the sensor box headless.
Data are stored in RAM, with enough to hold 15 days of readings at 15 minute intervals, with software running on a PC host able to download the readings for long-term storage. The display unit, meanwhile, offers an at-a-glance look at the most recent readings without having to load up the PC.
Harbour's project is documented in full on Hackaday.io.