Key Takeaways
1. The Casio F‑91W and A158W are popular, budget-friendly watches known for their durability and long battery life, with millions sold and over 60,000 positive reviews on Amazon.
2. Ollee Watch is a modification designed for Casio enthusiasts who want smartwatch features without a large display, allowing for a simple 5-minute installation of a new circuit board.
3. The Ollee modification introduces features like Bluetooth syncing, programmable timers, health tracking (step counting, heart-rate monitoring), and a customizable RGB backlight.
4. The installation process for the Ollee PCB is easy and requires no soldering, taking approximately 5–10 minutes with common tools, while maintaining the classic Casio look.
5. Reactions to the Ollee modification are mixed; while some purists disapprove, many enthusiasts appreciate the added functionality that enhances the classic Casio experience.
Casio’s modest F‑91W (along with its metallic A158W counterpart, currently priced at $27 on Amazon) has developed a strong fan base. It’s tough, budget-friendly, and delightfully straightforward—truly a digital workhorse that boasts a 7-year battery life and has sold millions. As one r/casio community member put it, the F‑91W (currently $19.90 on Amazon) is basically the “Honda Civic of watches” for those who like to modify them. Even its page on Amazon features “over 60,000” positive reviews.
The Birth of Ollee Watch
Ollee Watch is the creation of a wearable tech engineer and devoted Casio enthusiast who “didn’t want a smartwatch” on his wrist. He appreciated the simplicity and battery longevity of the Casio but desired some smartphone-like features without needing a large display or daily recharging. Thus, Ollee was born: a small printed circuit board that replaces the standard Casio module. In the founder’s own words, Ollee offers “a 5-minute swap of the circuit board that can transform the watch into something special.” It preserves the classic Casio appearance and battery life while introducing various new functionalities.
Enhanced Features
To begin with, the timepiece can now automatically sync through Bluetooth with your phone, offering world time, five programmable timers, a 1/100-second stopwatch, and even sunrise/sunset times using GPS. The alarm now includes a snooze option and hourly chime, plus it can play custom tunes (one user even included a Star Wars melody). On the health front, Ollee introduces an accelerometer for step counting, a heart-rate “pulsometer,” and an ambient temperature sensor—all tracked on the watch and sent to the Ollee app.
There are lifestyle perks too: a full-color RGB backlight that can be tinted to any color, a digital compass, and an NFC contact tag (for sharing links or IDs) in compatible resin-cased versions. The tiny gadget also features entertaining extras—like a flashlight mode, a digital tally-counter, and simple mini-games such as Pong or Blackjack—all navigable through the Casio buttons.
Technical Specifications
Inside, the Ollee PCB houses a modern microcontroller (ARM Cortex) with Bluetooth LE capabilities. It operates on a standard CR2016 coin cell: with performance ranging from about 10 months of heavy use to up to 3 years in ultra-power-saving mode. In contrast, a regular F‑91W might last over 7 years on one battery, but with fewer functions. When you access the Ollee app on iOS or Android, you can adjust all settings—alarms, time zones, fitness goals, LED colors, and more. The watch and app work together to stay in sync whenever they’re close.
Installation Process
Installing Ollee Watch into your Casio is surprisingly easy—no soldering is necessary. You simply take off the watch’s snap-on case back (a small prying tool or knife works), remove the original module and battery, and insert the Ollee board along with a fresh CR2016 battery. The unit is made as a “drop-in replacement.” In theory, it’s a quick job lasting 5–10 minutes. The kit comes with the Ollee PCB and an optional NFC tag; common tools like a case opener or small screwdriver and a pair of non-magnetic tweezers will be needed. After swapping the board, you just reseal the case (be careful to replace the rubber gasket for splash resistance) and pair the watch with the Ollee mobile app. Some skill is required to handle the tiny board, but early users report that the swap is “smooth and easy.”
Mixed Reactions
As with any third-party modification, opinions differ. A “purist” remarked that “if you want a smartwatch, buy a smartwatch,” dismissing Ollee as “a gold medal in the waste of time Olympics.” However, many enthusiasts enjoy it. A commenter on a Casio forum expressed that the Ollee “took an $18 Casio that’s been cherished forever and added some brains to it—Bluetooth, step tracking, sunrise/sunset, custom alarms, RGB backlight… still maintains that classic look… but now it communicates with your phone.”
The Ollee Watch modification is available directly from the maker’s website. The DIY circuit board kit costs $54.99, while for around $99.99, you can purchase a complete F‑91W/A158W (new watch plus pre-installed Ollee). To be fair, stock watches are widely available globally and can also be bought separately. The Ollee mobile app is free on both iOS and Android, and the developer provides a dedicated subreddit along with video tutorials (see above) to assist new users.
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