LED Matrix Watch Is The Smart Watch We Didn’t Know We Wanted

[Mile] put together this stunning LED matrix watch, on which the stars of this show are the 256 monochrome 0603 LEDs arranged in a grid on its face. The matrix is only 1.4in in the diagonal and is driven by a combination of an LED driver and some shift registers. The brain is an ATmega328p. We appreciate the extra effort taken to add a USB to UART adapter so the mega can be programmed over USB. It also contains all the necessary circuitry to charge and maintain the lithium battery inside safely.

Input into the device is done with a hall effect sensor which keeps the build from having any moving parts. The body is a combination of 3D printed parts and really fetching brass details connecting to the band.

If it weren’t over the top enough the build even has an ambient light sensor so the display can dim or brighten depending. We bet [Mile] is pretty proud to wear this on their wrist.

17 thoughts on “LED Matrix Watch Is The Smart Watch We Didn’t Know We Wanted

    1. Hmm. Maybe it’s a good idea to read first and only then comment.

      “Battery is charged via single-cell charge management montroller MCP73831. Lithium-Polymer cell is charged to 4.2 with set current of 300mA. Depending on the version MCP73831 supports variuos preconditioning and end of charge modes of operation. Maximum charging current can be set to 500mA. Load sharing circuit is not implemented since the circuit while inactive enters low power mode.”

    2. It seems to have been made clear that you’re wrong, but I don’t even understand what you said.
      “I doubt there’s a lithium battery, it’s probably a lithium battery instead” is… confusing.

  1. I like the idea of (re?)using the wrist strap holders.

    But I misread the first line,
    I thought the “the stars of this show” were going to bit monochrome photos of Keanu Reeves, Carrie-Anne Moss, Laurence Fishburne, et al… shown on the face of the watch.
    B^)

  2. I’m glad HAD doesn’t discriminate against older projects as not everyone has seen them before.

    Very cool watch, and that’s a hefty battery fit inside. I always struggle with battery size, always ending up smaller than I’d like to maintain a minimal case size.

    I don’t understand why more people don’t opt for a 32u4 though, as it’s >= the 328p on almost every measure and it doesn’t require the external usb/uart components. Although there’s now a Micronucleus bootloader for the 328p, the 32u4 is still dead simple.

    1. The 32u4 is great if you flash it ince and leave it alone. But if you have to do anh debugging over serial, it sucks. This mught not be the dault of the 32u4 itself, it could be the PC getting “confused” by the appearance of one device (the 32u4″s bootloader) which then diappears to be replaced by a COM port…. Then later you improve the cose and try to upload it to the 32u4, and half the time the Arduino software can’t see the microcontroller.

      If it works for you, great. All I know is that my problems went away when i went back to an ATmega + discrete USB IC. FTDI or CH340 both seemed to work for that.

      1. Yea, I know that issue. I suspect it’s more a fault of Windows, not assigning it the same com port when it reconnects. But to me, changing the port occasionally and resetting the project is a small price to pay for the advantage of built in USB. But I’ll acknowledge that most of my projects are severely space constrained, so being able to eliminate a number of components is of significant value.

      2. I’ve met that issue too. Really annoying. In the end the only way I could persuade anything to flash was to copy the avrdude commandline, and have my finger hovering over the enter key. Reset the micro then hit enter. None of the other tooling worked out.

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