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Melissa & Dave - Adventures at Sea

The ice maker rises again

There are moments.  Moments where you think to yourself – “No!  It shall not be!”.  Moments when you refuse to accept fate.  Moments when you resist the natural entropy of the universe which dictates that all things must come to an end.

Dave vs the Ice Maker is one of these things.

For those with good memories, Dave has been battling the Ice Maker for a long time.  While we were in Mexico, he found a critical design flaw that caused the motor to wrench on the internal assembly till it broke.  He reinforced the internal mechanism so in theory this couldn’t happen anymore.  And we installed a cooling fan to ensure the thing did not overheat in the small space in which it was installed.

But in the end, it still died a sad death.  Its controller board burned up.  So it no longer even powers up.  Bummer because there is no unit on the market small enough to fit in the cabinet in which we have it installed.  And seriously.  Ice.  Need it for a plethora of things including Sangria and Martinis.  We do have our priorities after all.

And well, good thing there just isn’t that much good TV to watch because apparently that gives MacGyver time on his hands.  In his own words: “I just now realized that the tray motor is a CW/CCW synchronous AC motor with 2 wires. How in the world does an AC motor reverse with only two wires? Something must be built into the motor to reverse the direction each time it is powered up. This changes the design flaw I originally speculated to they used a cheap motor with ambiguous start up direction. This revelation means the algorithm needs to be reworked to determine the motor direction at initial start (and hope it stays in sync).”

Yeah.  Welcome to the world of being married to MacGyver.

So what does he decide to do?  Well, what any self-respecting engineer would do.  Program up an Arduino (minicomputer about the size of a deck of cards) to replace the controller board of course.  Here’s the design specification document.  Um yeah.  The TV version of MacGyver might have been known for doing things by the seat of his pants.  My MacGyver is known for being not only good in a crisis but also methodical when time allows.  “This project replaces the power supply, display and control logic with M5stack, a couple relay boards, some switches, LEDs and a power supply. The new assembly will connect to existing inputs and outputs of the ice maker. The software is written in Arduino using a familiar round robin state machine.”

And just in case he gets bored, there’s a list of future improvements planned (and documented in the specification):

  • WiFi control
  • WiFi software upload
  • IOT control/status
  • Scheduling - turn off and on at certain times
  • External water supply/reservoir - if water low and ice not full, get some water
  • Can make noises with M5stack - e.g. water low
  • Variable length freeze cycles depending on temperature

So what was the end result?  We may never know.  Dave needed to take some voltage measurements to ensure his new electronics would interface correctly.  He powered the unit back up so he could take his measurements, and Voila!  It started working again all on its own.

Apparently, it just needed more love and attention.  Its back in its happy home aboard Apsaras.

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