Tag: Blue Opal
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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…
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Battery investigations
I’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 doesn’t add up to taking a battery from fully charged to near fully discharged…
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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.
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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…
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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.…
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Finding the right cable size for the water pump
Given the voltage drop at the pump, yesterday evening’s project was to wire the pump with 8 AWG (10mm sq) for the positive feed, and a bit of 2 AWG (35mm sq) for the negative feed. Unsurprisingly, the pump worked very happily, and the clamp ammeter gave me glimpse of ~10 – 11 amps of…