Future Watch Designs Rely on Flexible PCB Bases
In the realm of DIY tech projects, a new Youtuber named Sahko has captured attention with his latest creation - a retrofuturistic watch that exudes a unique blend of old-school charm and modern innovation.
The watch's centrepiece is a band encircled by HCMS3901 amber LED dot-matrix display modules. These modules, known for their warm, retro look and dot-matrix design, allow for the display of alphanumeric and symbolic characters in a retro style. Sahko recommends the HCMS3901 over the HCMS2901 for this project, indicating a close technical similarity between the two.
Each full brightness display on the watch draws one amp, similar to LED watches from the 1970s. However, due to power consumption concerns, the default state of the displays is "OFF", and the runtime with a LiPo pouch is only half an hour at full brightness without periodicity.
The modular LED matrix design of the HCMS3901 modules is controlled by a microcontroller, in this case, the STM32, to create the watch’s unique glowing band. The band is a flex PCB with no backing, aside from its own stiffeners, and is closed by a 4-pin connector that serves as both charge and USB programmer for the stm32u08 microcontroller.
Sahko has also included buttons on the band of the watch to activate it and control the brightness, preventing it from always blasting at full. The video of the watch's design and construction can be found on YouTube, where Sahko showcases different modes available, including a waterfall effect.
The challenge in mounting so many displays was the voltage on the supply rail dropping below the logic level. It's unclear if the newer version of the watch addresses this issue. A potential alternative for power efficiency could be using Nixie tubes.
The stm32u08 microcontroller runs the displays on the watch and has an RTC, allowing it to keep time. The watch's design embodies minimalism, contrasting with the maximalism of wrapping the wrist in displays.
If you have any tips or ideas for wrist-mounted clock projects, feel free to share them! Let's continue to explore the fascinating world of DIY tech and vintage electronics together.
The DIY tech enthusiast, Sahko, has also ventured into the realm of gadgets, creating a retrofuturistic watch with a band adorned with HCMS3901 amber LED dot-matrix display modules. In addition to this watch, he might contemplate projects involving wearables, powered by efficient alternatives such as Nixie tubes, to further delve into the intriguing world of technology.
