Why a 9-gram vario

Most pilots already carry a smartphone. The phone has GPS, a screen, a map app, a thermal database, a route planner. What it doesn’t have is a fast pressure sensor — phone barometers are slow, smoothed, and tuned for weather apps, not for telling you the difference between “we’re climbing” and “we’re climbing now”.

So a Bluetooth variometer only needs to do one thing well: feed the phone clean, fresh pressure data, and beep when you’re going up.

That’s what the mini BT is.

What we stripped out

• No GPS. The phone has one. Don’t pay twice.
• No screen. The phone has one. Don’t pay twice.
• No rechargeable battery. A CR2032 costs €1, lasts ~250 hours of silent flying, doesn’t degrade after 200 cycles, and works at –30 °C without complaining. Pop a new one in once a season.
• No marketing. This page lists weight, battery life, sensitivity, and what apps it pairs with. If those numbers look right, buy one.

What’s left

A 34 × 28 × 10 mm shell, 9 g with the battery, a pressure sensor sampled 60 times per second, a piezo with three volume levels, four buttons that pair as a wireless HID keyboard, and a BLE 5 radio that pushes pressure at 10 Hz, altitude at 1 Hz, temperature and battery on subscribe. Firmware updates over the air from any Chromium browser at config.flybeeper.com — no driver install, no cable, no app to sign up for.

Who it’s for

Pilots who already trust their phone for navigation and want it to react like a flight computer. Hike-and-fly pilots who count grams. Comp pilots who want a backup sensor that doesn’t add a charging cable to the pack. Pilots flying in the cold who are tired of warming up their main vario in their pocket.

Pilots who want a small thing that does one job and gets out of the way.