Open Source · v1.5.5 Beta

Your glucose.
At a glance.

A pocket-sized, open-source CGM display that puts real-time glucose data where you need it. Built for the diabetes community, by the diabetes community. No subscriptions. Just ~$40.

~$40
Total hardware cost
3
CGM sources supported
0
Subscriptions required
CYGM device showing glucose reading and weather on a yellow 3D-printed case

Everything you need.
Nothing you don't.

Designed from the ground up for one purpose — making glucose data visible, accessible, and actionable.

📊

Real-Time Glucose

Live readings from Dexcom Share, Nightscout, or LibreLinkUp. Large, clear numbers with trend arrows you can read across a room.

📈

6-Hour Trend Graph

Interactive touchscreen graph with target range markers. Tap any point to see the exact reading and timestamp.

🔔

Customizable Alarms

Set high/low thresholds with audio tones, visual LED alerts, and repeat-until-dismissed mode. Choose from 12+ 8-bit alarm sounds.

🌤️

Weather & Clock

Integrated weather display with automatic timezone detection, sunrise/sunset times, and location search — all on the home screen.

🔋

Battery Powered

Built-in battery monitoring with percentage display. Charge via USB-C and take it anywhere — nightstand, desk, or on the go.

📱

Touchscreen UI

2.8" capacitive touchscreen with full on-device keyboard for setup. No phone or computer needed after initial firmware flash.

CYGM device in purple case on a mantle

Built because it
needed to exist.

CYGM was born from a simple frustration: why does seeing your glucose data have to be expensive? Commercial CGM displays cost hundreds of dollars, require subscriptions, and lock you into ecosystems.

I'm Carl — a self-taught developer, a member of the diabetes community, and someone who believes technology should serve people, not profit margins. I started with a $20 ESP32 development board, a 2.8-inch touchscreen, and a lot of late nights learning embedded programming through trial and error.

CYGM is fully open source. No subscriptions, no accounts, no cloud dependency. Just a small device that does one thing really well — putting your glucose reading where you can see it. Every line of code, every schematic, every 3D-print file will be available for the community to use, improve, and share.

#WeAreNotWaiting

Small device.
Big capability.

Built on the JC2432W328 development board with ESP32-D0WD.

2.8"
Touchscreen
320×240
Resolution
WiFi
Connectivity
USB-C
Charging
ESP32
Processor
4MB
Flash Storage
RGB
LED Alerts
8-Bit
Speaker Audio

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.

Ready to build in minutes

Everything you need is available off the shelf. Order the parts, flash the firmware from your browser, 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.

~$20
View on Amazon →
🔊

Mini Speaker

1W 8Ω full-range speaker with JST-PH 1.25mm connector. Plugs right in for alarm sounds.

~$8
View on Amazon →
🔋

3000mAh Battery

Rechargeable LiPo battery for portable use. Our 3D-printed case is designed to fit this exact size.

~$12
View on Amazon →

Flash your device

Install or update CYGM firmware directly from your browser. No software to download — just plug in and go.

cygm-flasher

Requires Chrome or Edge on desktop · Uses Web Serial API

🖥️

Desktop required

The firmware flasher uses Web Serial, which requires Chrome or Edge on a desktop computer. Connect your CYGM device via USB to flash.

A CYGM device (JC2432W328 board), a USB-C cable, and a desktop computer running Chrome or Edge. No drivers or software installation needed — everything happens in the browser.
A full flash (merged binary) will reset all settings to defaults. After flashing, you'll go through the on-device setup wizard to configure your WiFi, CGM source, location, and alarm preferences.
Make sure your USB cable supports data transfer (not charge-only). Try a different USB port. On some boards, you may need to hold the BOOT button while plugging in. If the browser still doesn't see the device, try the CP210x USB driver from Silicon Labs.
Not currently. The Web Serial API is only supported in desktop browsers (Chrome and Edge). We're working on an SD-card based update method that won't require a computer at all.