Category: Sailing

  • Breakfast at Dalkey Island

    Breakfast at Dalkey Island

    Up before 6 AM today, and with a forecast of reasonably light winds out of the south, I decided to anchor off of Dalkey Island for breakfast and to see what it’s like to sit through a tide swing here – it could be a very nice place for the night with the right wind…

  • Sparks fly, broken alternator

    Sparks fly, broken alternator

    A suggestion from Dad was to take the wiring off the back of the alternator, clean the contacts, and reconnect them. Grime/corrosion there might be a reason for the voltage drop I’m seeing at the battery side of the circuit when the alternator is charging the batteries. I duly turned the engine starter battery switch…

  • Battery investigations

    Battery investigations

    Iโ€™ve been suspicious for a while about how hard my batteries for house are losing voltage over a ~ 12 hour day. I know the fridge compressor comes on periodically at 3 amps to keep the coolant moving around, but that doesnโ€™t add up to taking a battery from fully charged to near fully discharged…

  • Sending engine RPMs to the network, 3/x

    Sending engine RPMs to the network, 3/x

    A small re-write of the sender into a Click driven CLI, making hard-codes into CLI arguments.

  • Sending engine RPMs to the NMEA bus, 2/x

    Sending engine RPMs to the NMEA bus, 2/x

    It turns out that iNavX doesn’t support rendering ERRPM; it only supports the NMEA 2000 variant, PGN 127488. This led me down the path of trying to work out if I could send PGNs to the MiniPlex3 via the WiFi interface. The answer is sort of yes – you can send a specially crafted 0183…

  • Sending engine RPMs to the NMEA bus, 1/x

    Whilst Dad was visiting, we put his portable oscilloscope across the two terminals on the back of the tachometer, and found a very nice mV signal that changes frequency with engine revolutions. This means that a bit of circuitry plus a microcontroller will enable me to push the rev count to the boat data network.…