French summary: Cet article liste quelques idées que j'ai en tête, plus ou moins concrètes, pour surveiller et automatiser divers systèmes sur le bateau (essentiellement la production d'électricité et d'eau). Comme il s'adresse à un public d'informaticiens et d'électroniciens, très majoritairement anglophones, il est en Anglais.
Introduction
So I live aboard a 100ft Belgian barge, on the Canal du Midi. It has quite a few specialized systems, including an on-board oil electric generator, 12kWh worth of lead batteries, a converter from/to 230VAC and the batteries' 24VDC, solar panels, a shore electricity limiter, a water purifier and its tank, Internet through a 4G modem... This page describes what I've done and what I intend to do to monitor and control those system through software.
Victron gear
Most of my electricty gear comes from Victron. They have a good reputation, are one of the two mainstream brands for boats, and produce very good documentations--including the specs of the protocols needed to communicate with their systems.
I have 3 devices I want to monitor:
a battery monitor, which counts what goes in and out of the batteries. It has a 3.3V TTL serial line readily available, on which it publishes easy-to-parse ASCII text.
an MPPT, which stores solar energy into the batteries.
a charger-inverter, which pushes electricity from the shore or the genset into the batteries, and converts battery power back into 230VAC as needed. It also has a couple of nice features, such as shore power limitation and assistance, load smoothing to save the genset from sudden surges, etc. It talks MK2, a proprietary binary protocol, whose specs have been kindly sent to me by Victron.
I plan to do a bit more than just monitor the charger-inverter, actually: it can be remote-controlled by a dedicated panel, which can be emulated in software with a serial line. I'd like to make a simple Android app acting as such a panel. I could also decide to switch the charger on and off programmatically, or limit its intake current, depending on solar production, to use a mixed shore + solar electricity.
The control panel I look forward to emulate on my phone.
There are a couple of other things, either interesting or fun to monitor:
230VAC input. My meter has an impulsion output, so that's fairly easy.
Whether the genset is running. It allows to keep separate accounts of shore electricity consumption vs. that produced from fuel by the genset.
GPS position: the 4G router has a GPS chip in it, so it would be fun to correlate with solar panels' production. I'd like to also have orientation, but I don't think it has a compass, and I don't think a compass would be very accurate in a 60 tons steel hull.
3G and 4G signal strength, also correlated with GPS, and public positions of BTS antennas.
I'd probably like to check the individual consumption of some systems. Can be done with an amperemetric clamp on the main panel, or with some meter plug. For instance, if I knew how much the electric water heater costs, I could decide whether I'm in a hurry to install a solar / wood pellet heater. Beware, affordable clamps only monitor AC, not DC (they're based on AC transformers, not Hall-effect probes).
Finally, some non-electric things might also be worth logging:
Temperature: inside, outside, in the water. I wonder what's the net impact of water on the boat's temperature, compared to a house.
Maybe inside hygrometry, just because many air temperature sensors provide the information for free.
Water: production, and consumption (there's a 1.5 tons tank in between, which we fill with purified canal water in about 10-15h depending on turbidity). I wonder whether I can correlate the production, in liters per hour, to the weather, the GPS position, the age of the filters. Also worth investigating is the pressure loss between the beginning and the end of the tank filling process, due to filters clogging.