Quasi-Logarithmic Kitchen Timer
Frustrated by clunky digital and imprecise mechanical kitchen timers, an engineer custom-builds a "quasi-logarithmic" timer featuring an elegant analog display and intuitive knob control. This DIY project, showcasing clever UI/UX design and microcontroller wizardry, resonated with HN's love for solving everyday annoyances with bespoke engineering and a dash of retro flair.
The Lowdown
The author, lcamtuf, shares a common frustration: modern kitchen timers are either fiddly digital monstrosities or inaccurate mechanical wind-ups. Rejecting subpar options, they embarked on a personal quest to engineer a superior solution: a digital timer with the tactile satisfaction of an analog display and the precision of modern electronics.
- The Problem: Existing kitchen timers suffer from poor usability, either being clunky digital interfaces prone to getting dirty or imprecise, single-ring mechanical devices.
- The Solution: A custom-built digital timer featuring an analog meter display and an adjustment knob, prioritizing user experience and cleanability.
- Quasi-Logarithmic Scale: To balance precision and readability, the dial is divided into four linear sections (0-1 min, 1-5 min, 5-30 min, 30 min-3 hours), with 'self-documenting' labels indicating tick increments.
- Hardware & Aesthetics: A vintage switchboard-style ammeter (Crompton 244-05VG-LS) was repurposed for the display, given a custom face, and housed in a simple, easy-to-clean maple enclosure.
- Intuitive UI/UX: The timer activates with a tap of an illuminated button, and time is set with a knurled knob. It allows seamless adjustment during countdown and features a distinct alarm that can be canceled or extended.
- Electronics Core: An 8-bit AVR microcontroller ($1.50) handles timing and display via single-bit PWM, with an inexpensive op-amp driving the speaker for audio cues. The source code is provided.
- A Nod to Craft: The author playfully dismisses the idea of using LLMs for such a project, emphasizing the hands-on, no-AI approach, and promotes their electronics book.
This project stands as a testament to the idea that thoughtful engineering can elevate even the simplest household appliances, delivering a blend of vintage charm and modern functionality that off-the-shelf products often miss.
The Gossip
Dialing In User Experience
The primary discussion revolved around the 'quasi-logarithmic' dial design. While some commenters praised the approach as a smart way to manage time setting, others questioned the practicality of dedicating a quarter of the dial to 0-60 seconds, suggesting less precision is needed for typical cooking tasks. The author's rationale for equidistant ticks and self-documenting labels was highlighted as a design choice, with some users even finding the granular control useful for tasks like egg timing, contrasting with the general preference for broader increments for general cooking.
Analog Appeal vs. Digital Utility
Many commenters shared the author's frustration with existing kitchen timers, from clunky oven interfaces to imprecise mechanical ones. There was a strong appreciation for the 'dial-based' user interface, drawing parallels to the superior UX of older or Japanese appliances that prioritize physical controls over touchscreens and keypads. Some also offered alternative commercial solutions, like the "Thermoworks Extra Big & Loud Timer," acknowledging that while the DIY project is impressive, functional alternatives do exist for those not looking to build their own.
The Devil's in the Details: Nits & Niceties
Commenters delved into specific implementation choices, offering minor suggestions and expressing appreciation for the finer points of the design. Suggestions included tweaking the dial labels, such as replacing the '0' mark with a '10-second' label for consistency. There was also curiosity about the necessity of the 'wakeup' feature. On the positive side, many users enjoyed the tactile feedback and auditory cues, specifically praising the satisfying 'clicks and sounds' demonstrated in the project's video.