glucose-display ♥

Build your own Dexcom bedside display: live glucose readings, big and clear, on a ~โ‚ฌ30 ESP32 touchscreen. Large value with trend arrow, graph, speaker alarms, an amber night clock โ€” and it dims itself at night.

English & Dutch firmware 100% open source full setup on the screen itself your login never leaves the device GitHub Nederlandse versie
Not a medical device. This is a hobby project. Readings travel via Dexcom Share and can be delayed, missing or wrong. Base treatment decisions exclusively on your official Dexcom app or a blood glucose meter. This display's alarms are a nicety, never your safety net.

What you need

๐Ÿ“Ÿ The board (~โ‚ฌ30)

Guition JC3248W535C โ€” 3.5" ESP32-S3 touchscreen, 480ร—320. Search AliExpress for the model name. Nothing else required.

๐Ÿ“ˆ Dexcom with Share

A Dexcom CGM (G6/G7/ONE) with Share enabled and at least one follower in the app. The display signs in with your regular Dexcom account.

๐Ÿ”Š Optional

  • Small 8ฮฉ/2W speaker (JST 1.25) for alarms
  • LiPo battery (103450) for cordless use โ€” voltage and percentage are read out

Flash your board โ€” from the browser

Board on USB-C, Chrome or Edge, click Install, pick the serial port. Done in half a minute. The screen walks you through the rest.

  1. Read and accept the disclaimer on the screen
  2. Pick your WiFi from the list and type the password (on-screen keyboard)
  3. Enter your Dexcom login (server defaults to EU; US is one tap)
  4. Done โ€” your first reading shows up within a minute

Updating later? Run the installer again and choose not to erase โ€” all your settings and logins stay.

Everything it does

๐Ÿ“Š Daily overview

Tap the graph: time-in-range bar, average, lowest/highest and the number of lows over 24 hours. Graph window: 3/6/12/24 h.

๐Ÿ”” Alarm-clock-grade alarms

Low, high, falling-fast and no-data. Repeats until you tap (count configurable), three sound styles, high alarm optionally silent at night. A test menu lets you preview everything.

๐ŸŒ™ Night-friendly

Configurable night window: dim or an amber night clock. A good-morning greeting shows your overnight range.

๐ŸŽจ Personal

A name on the display (flowing script with a heart, or bold block letters) and six colour themes that run through everything.

๐Ÿ“ฑ Web interface

Check the value and change every setting from your phone's browser โ€” protected by a password that only exists on the device's own screen.

๐Ÿ”‹ Battery aware

Percentage and charge state on screen; on battery the display automatically dims to a configurable power-saving level.

Privacy & security

๐Ÿ” Your data

Your Dexcom and WiFi credentials are stored on the device only and can never be read or changed over the network. The device talks exclusively to Dexcom over TLS โ€” no other cloud, no telemetry, no account with us.

๐Ÿ›ก๏ธ Web interface

Guarded by a device-generated password (HTTP Basic Auth), hardened against DNS rebinding and cross-site posts. Meant for your own home network; don't expose the device to the internet.

๐Ÿ“– Open source

All code is public on GitHub (MIT). Audit it, build it yourself, improve it โ€” pull requests welcome.