Waterproof hardware lacking waterproof firmware

Smart watch with drops of water on it

Designing a smartwatch, making it waterproof is a no brainer. The Qualcomm Toq does an elegant job on the hardware, with only capacitive buttons and inductive charging, there’s no need for any kind of wholes in the body. But I was surprised to discover that the firmware isn’t waterproof. When the watch is immersed or gets many water droplets on it as a pictured above, it interprets each droplet as a touch and the UI goes crazy, paging through menues etc. Crushed under this erroneous touch spam, it crashes and locks up pretty quickly.

Lesson: Always test everything and remember to waterproof your firmware.

100V LED Buck driver

driver board with test LEDs
Here the driver is seen powering a string of 8 white LEDs in series for a total forward voltage of 27.2V from a 30V input at 15mA.

My electric bike is my primary mode of transportation so I need to be able to ride it under all conditions and at night that means I need light, lots of light. It seems silly to me to have a separate battery to power the lights when I have this nice big battery for the motor and it would be one more thing to remember to charge. The hiccup comes from the fact that the bike battery is at 48V (with a soon to come upgrade to 80V) so a switching power supply is needed.

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