Category: Uncategorized

February 18, 2018

Our new Simrad NSS9 EVO3 chartplotters have very quiet alarms, but they do have an alarm-out signal that can be used for an external alarm. To make sure we hear alarms for things like boats entering the radar guard zone and dangerous vessel on AIS, I built an external alarm using, at it’s core, a little Arduino single-board computer.

Here’s a very short video of the alarm in action…

(Note: the black box that says “Hear It” on the front is not part of the alarm. That’s actually a speaker for the SSB radio that has a built in DSP (Digital Signal Processor) to make voices much easier to hear and understand over the radio. Highly recommended.)

Here are the details in case you want to make your own external alarm (some assembly required ;-)…

The schematic for the circuit…

Since both the LED light and the alarm draw more current than the Arduino can safely supply, I’ve used two 2N2222 NPN transistors to switch them on and off. The external alarm signal from our Simrad EVO3 chartplotters is open-collector so when the alarm is activated, the alarm input is pulled low. When it’s not active, it’s tied to +5 volts through the 1K resistor. That resistor is a fairly low value so that the stray EMI from the SSB won’t trigger the alarm.

And a breadboard layout (done in Fritzing)…

Click this link for the Fritzing Files for the Above

I used an Arduino Nano but almost any Arduino will work. I picked the Nano because it has a built in voltage regulator and I can supply the alarm with ships 12 volts (which on Legacy, may run as high as 14.8 volts).

I put the extra bits on a perf-board and soldered the Nano on that same board (yes, I know it would have been better to socket the Nano but it turned out to be a tight squeeze to get the parts in the box).

The piezo is from Jaycar – here. It really isn’t quite loud enough and I may replace it with a louder buzzer.

I found the lamp housing at a local marine store. It’s not easy to find one for a boat that’s all-around red. I’ve been on the lookout for something that would work for this application for a while and finally found it at Steve’s Marine in Tauranga, New Zealand.

The lamp I used inside is also from a marine store and is an all-around white LED bulb similar to this one from West Marine: here. A red LED bulb would have been better, but I made do with what I could find locally.

And here’s the code (or sketch as it’s called in Arduino parlance):

chart_alarm_v1-4

There are some notes at the top of the sketch that I hope explain it pretty well. There, I noted that I should have selected a different digital I/O pin for the alarm in signal that doesn’t interfere with programming the Nano. That should be a very easy change.

-Rich

February 15, 2018

Leaving Phil’s Place restaurant after a wonderful Valentine’s Day dinner last night.

January 30, 2018

We’ve had continuing problems with the mixing elbow on our Yanmar 3YM30 engine: we’re on our forth now and it’s rusted away to the point that it’s leaking.  I was shopping for a new one online this morning when I found this stainless steel after-market replacement from HDI Marine.

I ordered one immediately and it’s on it’s way. The price was unbeatable at $275 US for the entire assembly. I don’t really need the lower part (that attaches to the engine), and they sell the mixing elbow alone, but it wasn’t too much more for the entire assembly. I’ll update this post as I gather experience with it. -Rich

Update: March 15, 2020

Over two years later and it’s still going strong! No sign of plugging up. I can usually tell by the RPM the engine reaches when I run it at wide open throttle. If all is well, it will get to about 3200 RPM. When it’s clogged badly, it doesn’t go above 2400 or so.   I’m very happy with this replacement elbow.

January 21, 2018

Every other year Tauranga hosts a very cool air show right over our boat! All we needed to do to attend was to drag our chairs up on deck, fill the wine glasses, and sit back in the best seats in the house.

Here’s some more of what we saw. Click an image to enlarge and scroll through.

And this guy below wasn’t going to be outdone. It’s a Pier F04 Cormorant – the latest in the fight against evil.

-Rich

January 20, 2018

We’ve just completed a long period of cruising which began with an unusually late departure: August 2016 from Opua, New Zealand. Since then we’ve traveled to New Caledonia, Australia and Tasmania, then back to New Caledonia, up to Vanuatu, and once again back to New Caledonia, all pretty much without a break.

We then returned to Opua (New Zealand) and after a brief stay  we quickly made our way to Tauranga. Now we’re taking a few months off from cruising. We’ll be working on boat projects, work protects, and some personal care projects such as going to a gym. For the next few months we’ll be living “apartment life.”

Now, as I finally finish the post, it’s nearing the end of January. We bought a car, go to the gym three times a week, have reconnected with old friends, completed a few boat projects, gotten our eye exams, and feel settled in. We even have a plant! (OK, it’s just one of those living herb plants they sell at the supermarket—I needed chives and this was the only way I could have them—but still, it’s symbolic.)

The best part is not constantly having to be on top of the weather forecast. Did you hear that wind pick up last night? Impressive! Wow, there’s some thunder; let’s unplug the computer. Torrential rain? Good thing we have new windshield wipers on the car! Heat? The gym has air conditioning—let’s get some exercise. Remnants of a tropical low are due next week; hope the weekly Gourmet Night in the park doesn’t get canceled. Yes, there are plenty of other things worry about, but for the time being, it’s nice to put aside weather concerns.–Cyndi