Everything your CYGM can do

Quick Start #

Five steps from a box on the table to a glucose number on the screen. You need the device, a USB-C cable, a 2.4 GHz WiFi network, and the login for whichever CGM service you already use.

Total: about 10 minutes

Home Screen #

Two cards. Time and weather on the left, glucose on the right. This is the screen the device sits on all day, and it is designed to be read from across a room.

Reading the glucose card

1. The big number is your most recent reading. Its colour tracks your own alarm thresholds — green in range, yellow approaching a warning, red past an alarm.
2. Under it, the signed delta (for example +17) is the change since the previous reading, and time-ago tells you how fresh it is: “Just now”, “1 min ago”, and so on.
3. The trend arrow glows and rotates smoothly to its new angle whenever the direction changes, so a change catches your eye without you staring at the screen.
4. A rapid rise or fall is drawn differently: two red arrows side by side that slide and pulse. That is a built-in visual alert — it fires on the trend alone, independent of your threshold alarms.
5. The semicircle arc around the arrow is a countdown to the next data pull. It is full right after a reading lands, drains as the minutes pass, sits empty when the next one is due, and turns blue while the device is actually fetching.
6. If a reading goes stale, the number greys out with a strikethrough and the age is shown, so an old value can never be mistaken for a current one.
7. Along the top of the card: battery with percentage, the bulb icon for the display sheet, and the gear icon for settings.

The time & weather card

• Current time and the full date.
• Weather icon and condition, current temperature, and today’s high and low.
• Your location name.
• Sunrise and sunset times along the bottom.

Gestures

Glucose Chart #

Tap the trend arrow on the home screen and the history opens full-screen. This is where a number becomes a pattern.

1. Pick a window with the tabs across the top, or swipe left and right on the chart to move between them. 1h3h6h12h24h
2. Tap any point on the line to inspect that exact reading — value and time.
3. The line is coloured by value, and the shaded band shows your target range as defined by your alarm thresholds.
4. The statistics bar along the bottom summarises the visible window.
5. Tap Close to return to the home screen.

What the statistics mean

Settings Menu #

Tap the gear icon on the home screen. Everything configurable lives behind one of these four rows or the two icons in the title bar.

1. CGM Settings — choose your data source and sign in. Details.
2. WiFi Setup — scan, join, and manage saved networks. Details.
3. Time / Weather — location, timezone, and how often weather refreshes. Details.
4. Alarms — the four glucose alarm tiers and, behind the gear in that screen’s title bar, the alert options.
5. ? in the title bar opens About: firmware version, Check for Updates, the SD logging checkbox, and erase device.
6. The red power icon powers the device off. You hold a confirm button to complete it, so a stray tap can’t shut you down.

CGM Setup #

The device doesn’t read your sensor directly — it reads the sharing service your sensor already publishes to. Pick the one that matches your setup. Each has something to arrange on the phone side first.

WiFi #

The device needs WiFi for glucose data, weather, time sync, and updates. There is no cellular fallback — if the network is down, readings stop until it comes back.

1. Open gear → WiFi Setup. The device scans automatically as soon as the screen opens.
2. Tap the refresh icon in the title bar to scan again if your network hasn’t appeared yet.
3. Tap a network name, then type the password on the on-screen keyboard. The keyboard supports shift (one character) and caps lock (tap shift twice); the eye icon reveals the password.
4. Connect. A progress overlay reports what’s happening, and the network gets a green dot once it’s saved.
5. To forget a saved network, tap the red × next to it.

Time & Weather #

One setting drives most of this screen: your location. Set it and the timezone, forecast, and sunrise/sunset all follow.

1. Open gear → Time / Weather.
2. Tap Search Location and type a city name or postal code. Results narrow as you type; confirm the one you want.
3. The timezone is derived from that location automatically, and the clock syncs over the network. You don’t pick it separately.
4. Choose a weather update interval — 15 min, 30 min, or 1 hr. Longer intervals mean fewer network wake-ups, which matters on battery.

Clock format, date format, and glucose units

The device supports both 12-hour and 24-hour clocks, alternate date formats, and both mg/dL and mmol/L for glucose. These follow your regional settings rather than needing to be picked one at a time — set the region correctly and the whole interface, including the alarm thresholds and the chart, speaks in your units.

Display & Night Dim #

Tap the bulb icon on the home screen. A two-page sheet slides up: brightness on page one, the night schedule on page two. It closes itself after about 30 seconds if you walk away.

Brightness & charging behaviour

1. Drag the brightness slider. The screen responds immediately, so you can set it by eye in the room you’re actually in.
2. “Dim when plugged in” is off by default — meaning that on USB power the screen simply stays on. That’s the intended way to run the device: plugged in, always readable, no waking it up to check a number.
3. Turn that toggle on if you want the screen to dim on charge too — useful in a bedroom where the device is plugged in overnight.

Night Dim and the night face

1. Turn on Night Dim and set a start and end time.
2. Pick a night level: 5%, 15%, or 30%.
3. Inside that window the screen drops to the level you chose and hands the whole display to one huge glucose number, colored by zone — green in range, amber near a warning, red at an alarm — with the trend arrow beside it.
4. The time moves to a small white readout in the top bar. That’s deliberate: at a sleepy 3am glance, a big clock and a big glucose value look alike. At night only one number is big, and it’s always the one that matters.
5. The dimmed bulb icon stays in the top corner all night, so the display settings are always one tap away.
6. Outside the window everything returns to the layout and brightness you had before.

Dimming and waking

• On battery, the screen dims on its own after roughly two minutes of no touches.
• Double-tap anywhere to wake it. The first tap only wakes the screen — it never activates whatever button happened to be under your finger, so you can’t snooze an alarm or open a menu by accident.
• The BOOT button on the board also wakes the device, which is handy in the dark.

Alarms #

Four tiers, each configured independently: High Alarm, High Warning, Low Warning, and Low Alarm. Warnings are the early nudge; alarms are the ones that mean now.

Configuring a tier

1. Open gear → Alarms and tap the tier you want to change.
2. Drag the threshold slider to the value that should trigger it.
3. Audio Alert turns sound on, and exposes the tone and a volume slider.
4. Repeat keeps the tone looping until you deal with it, instead of playing once.
5. Screen Flash flashes the display, and LED Flash flashes the on-board LED. Either works on its own if you need a silent alert.
6. Back on the Alarms list, the range bar across the bottom shows all four thresholds together — a fast way to catch an overlap or a gap you didn’t intend.

Choosing a tone

• 28 tones spread across seven pages, grouped from gentle chimes through to genuinely alarming sirens.
• Tap the green play button to preview any tone without selecting it.
• Random (Loud) is the interesting one: instead of a fixed melody it plays a fresh, unpredictable loud sequence every time. Familiar alarms fade into the background after a few weeks — this one can’t, because you have never heard it before.

When an alarm fires

The device takes over the whole screen: the glucose value at full size, a plain statement of why it fired, and two buttons.

• SNOOZE silences it for your configured snooze length. If glucose is still out of range when that expires, it fires again.
• DISMISS is a hold, not a tap — deliberately harder, so a half-asleep swipe can’t clear a genuine low.
• The BOOT button snoozes without needing to find the right part of the screen. Useful in the dark.
• Nobody home? If the alarm goes completely untouched for 30 minutes, it stands down on its own — tone included — and the display returns to the home screen. It counts as a snooze, never a dismiss: if the reading is still out of range when the snooze window ends, the alarm fires again. You can turn this off on the Unattended page of Alert Options; the control takes a three-second hold, so it can never flip by accident. (v0.15.2+)

Alert Options #

Tap the gear icon in the Alarms title bar for six pages of behaviour settings that apply across all four tiers. This is where alarms stop being a threshold and start being a system you can live with.

Quiet Hours & snooze

• Quiet Hours defines a window in which non-urgent alerts go visual-only — screen and LED still tell you, the buzzer stays silent. Set a start and an end.
• Snooze default sets how long the SNOOZE button buys you when an alarm fires.

Escalating volume

An alarm that is ignored gets louder over time instead of droning at one level. Starts polite, ends impossible to sleep through.

Data-gap alert

Warns you when readings stop arriving — the silent failure that a threshold alarm can never catch, because a device with no data has nothing to compare against a threshold. When it fires it also names the likely cause, so you know whether to look at the WiFi, the sensor, or the sharing service.

Predictive low warning

Projects the current rate of change forward and warns you roughly 20 minutes before you would otherwise cross your low threshold. Twenty minutes is usually the difference between eating something and needing help.

Rate-of-change alert

Fires on how fast glucose is moving rather than where it currently sits. A steep fall from a perfectly normal number is worth knowing about before it becomes a low.

Urgent-low safety floor

Unattended auto-snooze (v0.15.3+)

The last page controls what happens when an alarm rings into an empty room. With auto-snooze ON (the default), an alarm nobody touches for 30 minutes snoozes itself — screen and tone both — and re-fires if glucose is still out of range when the snooze ends. With it OFF, an unattended alarm keeps sounding until someone responds.

• Changing it takes a three-second hold on the ON/OFF control, with a progress fill so you can see the hold registering. A tap does nothing — deliberately. This is a safety behavior, not a preference to toggle in passing.
• Which setting is safer depends on your household: auto-snooze keeps a bedside device from flashing and buzzing all night at nobody, while OFF is the right choice if a ringing alarm should summon someone from another room.

Updates #

The device updates itself over WiFi. No cable, no computer, and your settings survive the process.

1. The device checks for updates automatically once a day in the background. If one is waiting, it tells you.
2. To check by hand: gear → ? (About) → Check for Updates. The check runs in the background with a progress overlay, so the screen stays usable.
3. If an update is available you’ll see the new version and an install option.
4. The device downloads and installs over WiFi, then reboots into the new firmware.
5. Your settings are preserved — WiFi, CGM login, alarms, location, display preferences. An update replaces the firmware, not your configuration.
6. After the reboot, the home screen shows a one-time “What’s New” card with the new version number and a short list of what changed. Tap OK and it’s gone; it never interrupts an alarm or the night face. (v0.16.0+)

Battery & Power #

The battery is optional. Plenty of people run the device permanently plugged in on a desk or a mantle — that is the intended setup, and the screen stays on for it.

• With an optional LiPo battery fitted, the top of the glucose card shows a battery icon and percentage. Tap the battery to show or hide the percentage; the choice is remembered.
• While charging, the battery icon animates so you can tell at a glance that the cable is actually delivering power.
• At 10% the device beeps to warn you.
• If it keeps draining, the device shuts itself down rather than running the cell flat — deep discharge is what kills a LiPo permanently.
• On USB power the screen stays on by default. Change that under Display if you’d rather it dimmed while charging.
• To power off deliberately: gear → red power icon, then hold the confirm button.

SD Card Logging #

Optional, and off unless you ask for it. With a microSD card in the slot, the device can keep its own copy of every reading it receives.

1. Insert a microSD card and restart the device so it is detected.
2. Open gear → ? (About). The “Save CGM data to SD” checkbox appears there once a card is present.
3. Tick it. From then on every reading is appended to a CSV file on the card.
4. Pull the card and open the CSV in any spreadsheet program — it’s plain text, no special software involved.

Tips & Tricks #

The things that aren’t obvious from the screens themselves — mostly learned by living with the device rather than by designing it.

Troubleshooting #

Find the symptom, read the likely cause, apply the fix. Work down each list — they’re ordered by how often each cause turns out to be the real one.

FAQ #