teardown

By aaron.axvig, Fri, 05/02/2025 - 16:12

Our Hatch Rest+ 2nd gen lost all battery functionality.  If lifted off of the wireless charging base for a fraction of a second it would die.  It was replaced under warranty, and customer support even saw the second one on the same account and said it would eventually develop the same issue.  So they replaced that one too!  Great customer service, which is really what is necessary to make the best out of what I'm sure is a bad situation for them.

Most exciting for me about the whole situation was the opportunity to tear apart the old one!

Tearing off the rubber pad on the bottom reveals some screws, and then the wireless charging module comes out.  Also found here are the barrel jack, and the power and sync buttons.

Here is the component side of the wireless charging board:

With the removal of the two middle screws shown in the first picture, the top of the cone comes off.  There are some tight wires.  The battery and speaker ones each have three wires and seemed to pop off easily.  The single wire is for the metal touch ring and I think I stretched that one to a damaging extent.  I didn't plan to put it back together though.

Access through the top is by prying off the speaker grill:

The speaker is held on by a few screws:

And within there is the battery:

The battery is a single 18650 cell:

It has a BMS.  The voltage directly on the battery was effectively 0V.

Now the main board.  This picture is after I had pried the SD Card out.  You can see that I damaged the card holder, but the card itself was fine.  Like many of the cable plugs within, it had a small dab of glue on it.

The SD card is 16GB and has a FAT32 filesystem.  I found about 7GB of mostly files on there.  Curiously, it seems to have all of the files for several Hatch products.  Folders include:

  • Rest_Sounds
  • RestMini_Sounds
  • Restore_Sounds
  • Sleep_Sounds

Another folder is named Downloaded and contains two interesting files.  BeRIOTGameMusicTTR_20220607.mp3 is an hour-long rendition of what I think is the Peaceful Flute music.  And RIOT_BrownNoise_CGV3_20240115.wav is a short clip of white noise.

Removed the plastic ring:

Here is the 7 segment display.  It appears to be individual LEDs behind 7 slots.

Here is the flip side of that main board:

Espressif ESP32-WROVER-E processor:

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