Personal weather stations

The following describes a few weather stations that have been constructed over the last 10 years. Time has passed and things have progressed but the main focus here is on the weather stations based on Fine Offset WH1030 which were current in 2015. The recorded output from the latest ecowitt weather station can be veiwed here.

Click on any image to display in large detail.

The very first prototype unit was constructed using an Atmel 328 processor connected to an aurel rx4mm5 433 mhz am receiver. This was programmed in assembler using the Atmel studio compiler. It was realised that there were limited libraries available for the Atmel compiler so the regime was changed to arduino, where there were many libraries for the anticipated peripheral support. These peripherals included a real-time clock, an atmospheric pressure recorder, and a light intensity recorder. The coding is now done completely in C or C++

The inital requirement was for a weather station to operate in a location with no access to mains electricity or WiFi connection. The decision was taken to use a mobile modem connection(sim900 GPRS modem) to access the internet and upload the information to weather underground. This set-up was powered by a 12v leisure battery which was maintained by a 100w solar panel and charge controller.

A time consuming task in adopting this approach required that the transmission protocal from the Fine Offset radio mast has to be decoded. The transmission protocol was a burst of 8 bytes of data transmitted every 47 seconds. This task was made a lot easier with publication of the work done by Kevin Sangeelee and Luc Small. Respect and thanks.

The first arduino unit, the Arduino uno. This mated very easily to a sim900 board providing the link to the internet.

A progression to the Arduino mega board which used a more powerful processor with more memory, and consumed less power than it's predecessor.

The final version using Arduino boards, in this case the nano. A tidier set-up and encapsulated to prevent any interference, usually perpetrated by spiders.

the location of this station was always problematic because the mast head was at the very limit of transmission range from the base unit. This situation resulted in many modifications, trying to improve the 433mhz radio reception. Most effective changes involved the adoption of ground plane sheets for the antenna.

Testing the esp32 board with integrated sim800 modem.

Esp32 unit showing the socket for the radio, which is moved off board to allow the inclusion of a ground plane.

Aurel receiver antenna on ground plane.

Image of a standard esp32 unit without the gprs modem.

This unit connects to a local wifi network and uploads information to a personal website.

The more modern weather stations can be supplied with a gateway unit which performs this function and which can be configured to send data to any web location

ESP32 unit with only wifi capability

The move to esp32 was very positive as this processor has a lot more memory than the Atmel based predecessors, and is a good deal faster.

Unfortunately the Fine Offset equipment has suffered a few failures in the last 10 years and It's now come to the point where replacement parts are no longer available.

Work is now in progress to introduce more recent hardware(Ecowitt) which looks like it will have WiFi capability in order to quickly upload information to the internet. Remote stations will still require modem access to the internet so decoding of the radio transmission will still be necessary. All the modems used here have so far communicated on the 2G network. At this time it's not clear what the future holds for 2G, but more recent modems are now starting to appear which use the 3G and 4G networks.