A pocket-sized, open-source display you build yourself. Live readings from Dexcom Share, LibreLinkUp, or Nightscout — with alarms that actually wake you, real trend charts, and updates over WiFi. No subscriptions, no app in the way, about $40 in parts.
Dexcom
G6, G7, ONE via Dexcom Share
Ready to use
FreeStyle Libre
Libre 2, Libre 3 via LibreLinkUp
Ready to use
Nightscout
Any CGM via your Nightscout site
Ready to use
CYGM is a second screen, not your source of truth. It is not a medical device, is not FDA-cleared or clinically validated, and should never be the sole basis for a treatment decision — always confirm the number on your official receiver or app first.
CYGM does one thing exceptionally well — it puts the number where you can already see it, and it makes noise when it matters.
A fresh number every 90 seconds
A countdown arc sweeps around the trend arrow so you always know when the next reading is due. Signed delta and time-since sit right beside it, and a stale reading grays itself out instead of quietly pretending to be current.
Trend arrows you catch from the doorway
Redesigned arrows with a soft edge glow that rotate smoothly between directions. On a rapid rise or fall, two arrows slide out side by side and pulse — a visual alert that lands before you've read a single digit.
Wake up for the number, not the noise
Four threshold tiers, 28 tones including a Random (Loud) roulette for when you've learned to sleep through the last one, and a full-screen takeover with SNOOZE and DISMISS buttons big enough to hit at 3am.
Alarms are a convenience layer. Keep the alerts on your official CGM app or receiver switched on.
Quiet hours, escalation, early warning
Schedule a window where non-urgent alerts go visual-only. Unacknowledged alarms step louder every few minutes. A predictive warning fires up to ~20 minutes ahead of a projected urgent low, and a data-gap alert speaks up when readings simply stop arriving. The urgent-low floor cannot be switched off.
Charts with the numbers worked out
1, 3, 6, 12, and 24-hour views with Low, Average, High, Time-in-Range, GMI, and CV calculated for you. Prefer the headline? Swipe left on the glucose card for a big-number view.
Three CGM sources, all shipping
Dexcom Share, LibreLinkUp, and Nightscout are each fully supported today. Pick yours on-device during setup and switch later without touching a cable.
A night face built for 3am
Scheduled Night Dim drops the brightness on your timetable and hands the whole screen to one huge glucose number, colored by zone — green in range, amber near a warning, red at an alarm. The time shrinks to a small white readout in the top bar, so a sleepy glance can never mistake the clock for a reading. Wakes on a double-tap that never presses anything by accident.
Stays awake while it charges
Plugged in, the screen stays on by default — a nightstand device should behave like one. Dim-when-plugged-in is a single toggle away if you'd rather it settle down.
mg/dL or mmol/L
Switch units on-device in a single tap. Every screen, chart axis, and alarm threshold follows along without a reset.
Weather, clock, 80+ timezones
Local conditions, temperature, sunrise and sunset, date and time. It earns its place on the shelf even in the minutes between readings.
Updates arrive over WiFi
After the first flash, new firmware installs over the air — no cable, no computer, and no re-entering your settings.
Built to pick itself back up
A hardware watchdog recovers the device if anything wedges, and optional microSD logging keeps a CSV of every reading for when you want the receipts.
Gallery
See it in action
Finished builds in real rooms, plus every screen captured straight off a running device.
Swipe for more →
Captured on-device
Swipe for more →
Use Cases
A display for every context
Whether it's your nightstand or a nursing station, CYGM fits right in.
Bedside Monitor
Place it on your nightstand. See glucose readings at a glance without reaching for your phone. Night-time alarms wake you when levels are off.
School Nurse's Office
Give school staff visibility into a student's glucose without needing their phone. A simple, dedicated display that anyone can read.
Clinic or Care Facility
Affordable enough to place at every nursing station. Monitor residents with CGMs from a small, always-on display right at the desk.
Our Story
Built because waiting wasn't an option
CYGM was born out of a simple need: a dedicated glucose display that doesn't depend on a phone. Something you can place on a nightstand, a desk, or a nursing station — and just glance at.
Commercial options are expensive, proprietary, and often require subscriptions. CYGM is the opposite: open-source, ~$40 in parts, and built by the community that needs it most.
This project is part of the #WeAreNotWaiting movement — a global community of people with diabetes and their families who build their own tools because the market moves too slowly.
#WeAreNotWaiting
Specifications
What's actually inside
Off-the-shelf parts, nothing exotic — and an honest account of what this hardware can and can't do.
Processor
ESP32 dual-core microcontroller with built-in 2.4GHz WiFi
Capacitive touchscreen — tap, swipe, and double-tap to wake
Audio
Piezo buzzer driving 28 selectable alarm tones, plus an optional mini speaker
Status light
RGB LED for a glanceable in-range, high, or low state from across a dark room
Power
USB powered, with an optional LiPo battery for portable and backup use
Storage
microSD slot for optional CSV logging of every reading
Refresh
A new reading roughly every 90 seconds
Data sources
Dexcom Share, LibreLinkUp, or Nightscout — selected on-device
Units
mg/dL or mmol/L, switchable at any time
Updates
Over-the-air firmware updates over WiFi after the first flash
Cost
Around $40 in parts, plus a free 3D-printable case
Honest limits
The radio is 2.4GHz only — it will not join a 5GHz-only network. Readings arrive through your CGM provider's cloud service rather than straight from the sensor, so the device is only ever as current and as available as that service is. And the sensors themselves publish a new value about every five minutes, which is the real ceiling on freshness no matter how often the device asks.
Build Your Own
Ready to build in minutes
Everything you need is available off the shelf. Order the parts, set up the firmware, and you're done — no soldering, no coding, no complicated setup.
📟
ESP32 Display Board
2.8" touchscreen development board with WiFi, USB-C, and microSD slot. The heart of CYGM.
🔊
Mini Speaker
1W 8Ω full-range speaker with JST-PH 1.25mm connector. Plugs right in for alarm sounds.
🔋
3000mAh Battery
Rechargeable LiPo battery for portable use. Our 3D-printed case is designed to fit this exact size.
Flashing firmware requires a desktop or laptop computer. Visit this page on your computer to flash your device.
Google Chrome or Microsoft Edge USB data cable (not charge-only) Device connected via USB
Flash CYGM firmware directly from your browser. Requires Google Chrome or Edge, a USB data cable (not charge-only), and your device plugged in via USB.
v0.16.0Beta
Enter Boot Mode First
Press and hold both BOOT and RESET buttons at the same time
Release RESET while continuing to hold BOOT
Click “Install Firmware” below and select your COM port
Keep holding BOOT until the progress reaches ~5%, then release
Wait for the flash to complete (~60 seconds)
If you don't see a COM port, install the CH340 driver linked below.
Flashing will erase all saved settings (WiFi credentials, alarms, preferences). You will need to re-enter them after flashing.
You're on a desktop or laptop running Chrome or Edge — Web Serial doesn't exist in Safari or Firefox
You're using a data USB cable. A charge-only cable will never show a COM port, and it's the single most common reason this fails
The CH340 USB driver is installed if no port appears in the picker — the download link is just above
You're ready to hold the BOOT button if prompted, following the five steps above
What happens next: the device is erased and rewritten, which clears everything stored on it — WiFi credentials, your CGM login, alarm thresholds, and preferences. The whole thing takes about two minutes, and the device reboots into the setup wizard when it finishes.
CYGM is not a medical device and is not FDA-cleared. Keep using your official receiver or app for treatment decisions.
Flash complete! Unplug USB and power on your device — it will boot into the setup wizard.
An error occurred. Check your USB cable, enter boot mode, and try again.
Your browser doesn't support Web Serial.
Use Google Chrome or Microsoft Edge on desktop to flash directly from the browser, or download the firmware and flash manually:
Sound engineer, lighting tech, and stage manager in the live entertainment industry by trade — hobbyist developer by passion. When my step-daughter was diagnosed with Type 1 Diabetes, I knew I had to do something. With the incredible support of my wife Stefanie, CYGM was born: an affordable, open-source tool to make life a little easier for the families who need it most.
Based in Auburn, WA. Driven by a simple belief: if I can help make someone's life easier, I should.
Medical disclaimer — CYGM is an open-source hobby project and is not a medical device. It is not FDA-cleared, not clinically validated, and carries no regulatory approval of any kind. It must never be the sole basis for a treatment decision: always confirm the number on your official CGM receiver or app before you dose, treat, or act on what you see here. Readings reach the device through your CGM provider's cloud service, so they can be delayed, incomplete, or unavailable without warning, and the alarms depend on WiFi, on that service, and on the device staying powered. Treat every alert as a convenience layered on top of your official ones, never as a replacement for them. CYGM is provided as-is, with no warranty, and you use it at your own risk. The developer is not responsible for any adverse outcome arising from its use.
Shop
Get your CYGM device
Shop
The CYGM Store
Get a pocket-sized CGM display — assembled and ready to go, or as a kit you build yourself. Open-source firmware, no subscriptions, yours forever.
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US Shipping
Open Source
Product
Complete Device
Assembled, tested, and firmware-flashed. Plug in and go.
CYGM Complete
Everything you need in one box. Hand-assembled with care, fully tested, firmware pre-loaded. Just connect to WiFi and enter your CGM credentials.
What's Included
JC2432W328 Board
1W Speaker
3000mAh Battery
3D-Printed Case
USB-C Cable
4x M3x10 Screws
Black
Select your case color above before pressing Buy. Default is Black. More colors coming soon as the project grows.
$50
+ $4.95 flat rate shipping
Product
DIY Kit
All the electronics — you print the case and assemble it yourself.
CYGM DIY Kit
For makers and tinkerers. All electronic components included — just 3D-print a case (STL files provided) and put it together. Flash firmware via the web flasher on this site.
What's Included
JC2432W328 Board
1W Speaker
Li-Po Battery
USB-C Cable
4x M3x10 Screws
Note: 2mm Allen Key required for assembly (not provided)
$40
+ $4.95 flat rate shipping
Support
Support the Project
CYGM is open-source and built by a family. Donations help fund components, hosting, and development time. Every dollar makes a difference.
Donate to CYGM
Your support keeps this project alive. No amount is too small — it all goes directly toward building and improving CYGM devices for the diabetes community.
$
$25One-time donation
Info
Shipping & FAQ
Shipping
Every CYGM is hand-assembled and tested by our family. Most orders ship within 7 business days, though occasionally we may need a bit longer if we're waiting on components. We'll keep you updated via email with tracking once your device is on its way.
Returns
30-day return policy for unopened items. Defective devices replaced at no cost. Contact us at support@cygm.me for any issues.
Warranty
30-day hardware warranty. Firmware updates are free forever via OTA. Open-source means you can always fix, modify, or improve it yourself.
Support
Setup help via the Device Guide on this site. Community support via GitHub Discussions. Direct email: support@cygm.me.
CYGM currently supports Dexcom (G6, G7, ONE via Dexcom Share) and FreeStyle Libre (Libre 2, Libre 3 via LibreLinkUp). Both are included in the firmware — you choose your provider during setup. Nightscout support is in beta testing, which will allow any CGM to work via the Nightscout API.
No. CYGM is a one-time purchase. Firmware updates are delivered free over-the-air (OTA). The device pulls data directly from your existing CGM provider account — no additional services or fees.
The Complete Device arrives fully assembled with a 3D-printed case and firmware pre-installed — plug in and go. The DIY Kit includes all electronic components; you 3D-print the case yourself (STL files provided) and flash firmware using the web flasher on this site.
Currently US only. International shipping is coming soon — follow us on GitHub for updates.
No. CYGM is a display accessory — it shows data from your existing CGM system. It is not FDA-approved and should not be used to make medical decisions. Always refer to your official CGM receiver or app.
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