I thought I'd start a new thread after reading posts from Shaggy and Lazzz on the VSR thread. Who else is using microcontrollers or RPis for boating applications?

I did some work with PICs onboard a few years back, but now mostly use Arduino Nanos. They're dirt cheap (about $7 from Ebay) and very easy to use. But in one of my recent projects I used a Particle Photon - a bit like a Nano but with a wifi system onboard. You don't even need a USB connection to update firmware - it's all done by wifi. I have the Photon monitoring the NMEA bus, saving all NMEA data (wind, GPS data, depth, etc) locally every minute, and keeping data for the last hour. This in turn communicates with an Android app that I've written, that allows me to chart any of the NMEA variables. There's an example output below (not underway, just 40 minutes tied up).

I find this very useful when cruising. For example:
- when motoring in the calm of the morning, and waiting for a forecast sailing breeze to come in, watching the chart of True Wind can help you determine whether it's "really started".
- When tacking downwind, or heading up above the lay line to get better apparent wind, watching the chart of CLV (closing velocity on waypoint) tells you whether your actions had a useful effect.
- If offshore on the east coast, watching the temperature chart helps you understand whether you're in the EAC.

Having the display on the phone means it's easy while underway and on deck to noodle around the various charts - both me and my wife have it installed.

So - anyone else for show and tell?