Frequently Unasked Questions
What on earth is that thing?
BeachDisplay (for lack of originality in picking names) is a solar powered, outdoor display system. The intended use is to provide beach goers an easy method to receive notification of current and future beach conditions, and perhaps a few other tidbits that would be handy to know, without having to fumble around on the web to find the information. It provides an extremely low maintenance method to automatically update the data as conditions change.
What was the inspiration?
Laziness was the principal motivator, but once I got the idea stuck in my head, I had to make it a reality. We (my wife, actually) were asked if we could post (as in a piece of paper) the beach water bacterial count so that people would know that it was safe to swim. Knowing that we were likely to be away for extended periods of time (in early 2020 PC (pre-covid), when we thought we could travel), I knew that it was only a matter of time before that system broke down. Much less the problem of dealing with wet paper, yuck!
How's it work?
BeachDisplay (well, the prototype) is based on an Arduino MKR1000. It uses WiFi to connect to a server to obtain the current data, and to post a small amount of telemetry from the hardware. The server handles all the data collection and processing. Data is pulled from the server as a JSON formatted string, once an hour (configurable, but that seems good enough). Battery draw is higher than I like, about 5mA average (which is mostly driven by the display refresh time and the time it takes to connect and transfer data, but it has a 100mA-hr battery. I'll leave the math to you. The display updates roughly about every 6-8 seconds (also configurable).
The system spends most of its time in a deep sleep state. When awake it handles communications to the server, the display and battery. Since this is meant to be outdoors year round, the temperature is monitored to determine if it is okay to charge the battery. The case and all connectors are environmentally sealed.
Oh, and by the way, the total hardware cost was less than $100. My time on the other hand...
Who's a good dog?
Dresden is, of course ;) Can you find him? The rest of the crew are Atticus, Beatrix, and Menolly.
They're good too when they want...
Version 2 has been started! Spending some time cleaning up the design repos, but I'm adding a few new features, a larger display, and a new comms architecture. Stay tuned, same bat time, same bat channel.