Ollee Watch: The Drop-In Bluetooth Brain That Turns a Vintage Casio Into a Smart Watch
TL;DR: Ollee Watch (https://www.olleewatch.com/) is a $55 drop-in replacement circuit board for vintage Casio watches on the 593 module family, including the F-91W, F-84, A158, and A159. No soldering is needed. You swap the PCB, pair the free phone app, and gain Bluetooth time sync, world time, sunrise and sunset, 5-day weather, step counter, RGB backlight, NFC tag, and wireless firmware updates while keeping the iconic look. A pre-assembled watch costs $99 when in stock. Battery life runs 10 months daily or 3 plus years in power saver mode.
What Is Ollee Watch?
Ollee Watch is a drop-in Bluetooth replacement mainboard that converts a classic Casio F-91W, A158, or other module 593 watch into a connected smart watch without changing its iconic look. Open the case, lift out the original Casio PCB, transfer the battery contact, drop in the Ollee board, close it up, and pair with the free Android or iOS app. The familiar 7-segment LCD stays, but behind it now sits an ARM Cortex-M4/M0+ processor with Bluetooth Low Energy, an accelerometer, a loud buzzer, an RGB backlight, and an optional programmable NTAG213 NFC tag. There are two flavors: Ollee Watch One with RGB LED backlight and NFC support, and Ollee Watch EL with an electroluminescent panel and 4 brightness settings.
Why the Humble F-91W Deserves Superpowers
The Casio F-91W has been in continuous production since 1989, sells for around $20, survives about 3 million units a year, and runs up to 7 years on one coin cell. It’s the watch of presidents and pop culture, a field-work legend, and the default beater for hams, hikers, and makers. Its weakness was never the case or the display. It was the frozen-in-1989 feature set: no sync, plus or minus 30 seconds drift a week, one alarm, green-only backlight, and zero awareness of where on Earth you are.
Ollee Watch keeps everything people love (weight, size, pushers, water resistance of the unmodified case, the honest LCD) and replaces only the brain. The result still looks, wears, and sips power like a Casio, but behaves like a modern connected instrument.
One vs EL: Which Board to Buy
| Feature | Ollee Watch One | Ollee Watch EL |
|---|---|---|
| Backlight | RGB LED, color and duration configurable, 3-mode flashlight | Electroluminescent panel, 4 brightness settings |
| NFC tag (NTAG213, programmable) | Optional, resin F-91W only, not A158W | Not available |
| Processor and radio | ARM Cortex-M4/M0+, Bluetooth LE | ARM Cortex-M4/M0+, Bluetooth LE |
| Accelerometer and gestures | Yes, step counting plus tilt-to-wake auto light | Yes |
| Buzzer | Loud alarm buzzer | Loud alarm buzzer |
| Battery | CR2016 coin cell | CR2016 coin cell |
| Battery life | 10 months daily use, 3 plus years power saver | 10 months daily use, 3 plus years power saver |
| Best for | Tinkerers, NFC experiments, color fun | Readers who want soft even EL glow |
Both boards work through the same phone app with free Android and iOS builds, wireless firmware upgrades, and sync with Apple Health and Google Health for steps. Official compatibility covers the F-91W, A158W, F-105W, and A168, and the community has fitted the F-84W, A159W, A171W, and W-59 since they share similar module 593 layouts.
Features That Matter on the Wrist
- Bluetooth time sync: zero drift per week once paired. The watch follows your phone instead of wandering 30 seconds weekly.
- World time: multiple zones a few button presses away, set from watch or app. Handy for scheds, nets, and DX windows.
- Sun, moon, and tide: sunrise and sunset for your location, moon phase, tide times. Set location once in the app.
- 5-day weather: daily high, low, feels-like, conditions, precipitation, humidity, and UV index on the small screen.
- Step counter: accelerometer-based counting with daily goal and alert, stored 30 days in the app.
- Alarms, timers, stopwatch: configurable day alarms with chime, snooze, and hourly beep, up to 10 programmable timer presets with interval and fast modes, and a 1/100-second stopwatch with logging up to 24 hours.
- Tally counter, temperature display, databank: everyday utilities that suit field logging and contest counting.
- Flashlight and games: 3-mode backlight flashlight plus character-based BlackJack and Ping tech-demo games.
- Customization: watch faces, app order in the mode cycle, backlight color and afterglow, battery saver, tilt-to-wake auto light.
- Heart rate helper: no optical sensor. This is a pulsometer face. Count 20 beats on your wrist, stop the timer, and the watch computes BPM from the elapsed time.
The app holds steps and timed events for up to 30 days, pushes alarms and time zone settings to the watch, and handles firmware updates over the air.
Installation: No Soldering, Just Patience
StrapHabit reviewer Nick Lehner documented the full swap into an A158, and Ollee publishes step-by-step instructions plus a YouTube video at https://www.olleewatch.com/get-started-one. The honest summary: if you can change an A158 battery, you can do this mod.
- Gather a small Philips screwdriver, a flathead screwdriver, and tweezers. No tools ship in the box, which holds the module, NFC chip, and a sticker.
- Remove the 4 caseback screws and lift the back. Work on a clean tray so tiny parts can’t roll away.
- Separate the LCD from the original circuit board, exactly as during a battery change.
- Transfer the battery contact to the Ollee board. This is the fiddliest step. A small screwdriver and tweezers make it easy.
- Drop in the Ollee board, skip the original Casio PCB entirely, and reassemble in reverse. Skip the NFC chip if you have no use for it, since it complicates the stack.
- Install the phone app, pair over Bluetooth, set location and preferences, and sync time.
Total hands-on time is well under an hour on a first attempt. Take a phone photo of the original stack before lifting anything so the contact orientation is on record.
Battery Life: The Number That Sells It
Smartwatches that demand a charger every night trained everyone to expect power anxiety. Ollee Watch instead runs a CR2016 coin cell for about 10 months of daily connected use with default settings, stretching past 3 years in power saver mode. That is shorter than the stock 7-year Casio cell, but it is in a different universe from rechargeable smartwatches. For EDC, field days, and travel, a watch that you never plug in wins.
Ollee Watch vs the Alternatives
| Option | Price | Display | Sync | Standout | Catch |
|---|---|---|---|---|---|
| Stock Casio F-91W or A158 | About 20 to 30 dollars | Original LCD | None, drifts weekly | 7-year battery, iconic, cheap | Frozen 1989 feature set |
| Casio F-91W plus Ollee Watch DIY kit | About 85 dollars total | Original LCD | Bluetooth phone sync | RGB or EL light, weather, sun times, steps, OTA updates | Install it yourself, 10-month battery |
| Pre-assembled Ollee Watch | $99 | Original LCD | Bluetooth phone sync | Zero surgery | Frequently out of stock |
| Sensor Watch and Sensor Watch Pro | From $35 board | Original or upgraded display | None by design | Fully programmable faces, open firmware | No phone sync, you write the code |
| Casio ABL1000WE | About $95 | Similar steel look | Bluetooth | Factory warranty, no install | Larger 41.6 mm case, fewer smart extras |
StrapHabit concluded the kit costs nearly double the donor A158 and lands near watches with native step counting, but none of those preserve the small classic case plus the mod community fun. If you want factory polish, buy the ABL1000WE. If you want the vintage silhouette with modern brains and you enjoy the install, Ollee wins.
A Ham Radio Field Watch?
This is hamradio.my, so here is the field angle. Sunrise and sunset on the wrist helps plan greyline DX without pulling out a phone. World time tracks UTC plus the DXpedition zone. The interval timer paces antenna tests, satellite pass drills, and contest exchanges. The tally counter logs contacts at a demo table. The loud buzzer actually wakes you for a 4 AM sched. And 10-month battery means the watch is alive when the Field Day box opens, unlike the dead smartwatch in the same tote. Pair it with a NATO or FKM rubber strap for sweat and rain, and it becomes a proper SOTA and POTA companion.
Honest Limitations Before You Buy
- Supply is limited and the $99 pre-assembled version sells out. The DIY kit can take weeks to arrive.
- NFC works on resin F-91W builds only, not on A158W metal-case models.
- The heart rate face is manual pulse math, not a sensor. Fun, not medical.
- No third-party app store. Games are character tech demos, not Apple Watch apps.
- Language purists should note the 7-segment LCD can’t show rich text, and some commenters wish for a 16-segment upgrade.
- Battery swaps mean reopening the case, so keep spare CR2016 cells and respect the gasket if you care about water resistance.
Frequently Asked Questions
What is Ollee Watch in one sentence?
Ollee Watch is a $55 drop-in Bluetooth mainboard that adds phone sync and smart features to classic Casio watches.
Which Casio models fit the Ollee Watch?
F-91W, A158W, F-105W, and A168 officially, plus F-84W, A159W, A171W, and W-59 by community testing.
Do I need to solder anything?
No. The swap uses screwdrivers and tweezers only, with no soldering required at any step.
How long does the battery last?
About 10 months with daily connected use, or more than 3 years in power saver mode on CR2016.
Is a pre-assembled Ollee Watch available?
Yes, a $99 pre-installed F-91W is sold on the store page, but it is frequently out of stock.
Sources and Further Reading
- Ollee Watch official store: https://www.olleewatch.com/
- Ollee Watch get started and installation guide: https://www.olleewatch.com/get-started-one
- Liliputing coverage: https://liliputing.com/ollee-watch-brings-smartwatch-features-to-the-casio-f-91w-with-a-mainboard-replacement/
- StrapHabit review and installation in Casio A158: https://straphabit.com/blogs/straphabit-reviews/ollee-watch-review-and-installation-in-casio-a158
- Ollee Watch companion app on Google Play: https://play.google.com/store/apps/
- TechEnclave owner discussion: https://techenclave.com/t/ollee-watch-vintage-casio-f91-a158-mod/401496
- Sensor Watch open programmable board: https://www.tindie.com/products/joeycastillo/sensor-watch/
- Casio F-91W product page: https://www.casio.com/us/watches/casio/product.F-91W-1/
73
Post Comment