CoolLED Web Controller, by: Brian Klier

HTML5/JS software based on a port of CoolLedDiy: send text and graphics to a CoolLED LED sign over Bluetooth LE through your browser.

Not connected

Mode Speed 127 Brightness

Web Bluetooth works in Chrome, Edge and Opera (desktop/Android), over HTTPS, localhost or a local file. Firefox and Safari do not support it.

Show all Bluetooth devices (if your sign is not listed)

Panel settings

Family Columns Rows RGB sign: send 3 colour planes (Light1248/536) BLE chunk bytes Serial baud

Panel size is read from the sign’s advertisement when the browser allows it; otherwise enter it manually. The family is guessed from the device name.

Using a Windows COM port instead

CoolLED signs speak Bluetooth Low Energy (GATT service FFF0, characteristic FFF1). Windows does not turn BLE devices into COM ports, so pairing the sign in Windows Settings will not create one. The serial option only helps with a BLE-to-UART bridge (e.g. an ESP32) that forwards raw bytes to FFF1.

Insert colour: Rainbow (ignore tags)

Colours are tags in the text, e.g. {r}Red {b}Blue. Tags: r y g c b m w.

Font Size Bold Letter spacing Default colour

Size and Bold apply to system fonts only. Preview approximates the selected mode and speed.

Drag on the source image to use just a portion of it (optional):

Lock to sign shape Fit Dither Auto-contrast Invert Brightness cut-off

Images are shrunk in several smooth steps, then converted to the sign’s colours (8 colours on RGB signs, one colour otherwise; UX signs keep full colour). Brightness cut-off: lower lights more pixels, higher fewer (it shifts the result brighter or darker, with or without dithering).

Colour Eraser

Live preview with current mode and speed:

Eraser

Frame time 200 ms Animation size ×

Fit to this sign

Align Scale RGB plane layout

Live preview (what the sign receives, at the frame time above):

Save, load and GIFs

Name

Drag on the GIF to use just a portion of it (optional):

Lock to animation shape

Dither Fit Auto-contrast Brightness cut-off

Preview of the first frame as it will be converted:

Pixel size GIF import converts to 8 colours at the animation size above (max 40 frames).

Click an animation to load it into the Animations tab.

Open this page with parameters in the address bar (or after a #) to connect and send automatically. Example:

Parameter	Meaning
`device`	Sign name or the start of it (e.g. `CoolLEDX-8313`). Browsers do not expose MAC addresses.
`deviceid`	Exact id of a remembered sign (see Remembered signs below)
`connect=1` `close=1` `auto=0` `ui=min`	Only connect · disconnect when done · fill in the page but don’t run · hide the interface
`fam` `cols` `rows` `rgb` `chunk`	Panel: 1248, 536, M, U or UX · columns · rows · 1/0 RGB planes · BLE chunk 20, 100 or 180 (remembered for next time)
`text`	Text to send. Colour tags `{r}{y}{g}{c}{b}{m}{w}` work inside it
`color` `font` `size` `bold` `spacing` `rainbow`	Default colour (name or hex) · font name or `unicode` · px size · 1/0 · letter gap · 1/0
`anim`	Library animation (file name or title, e.g. `fire`). Wins over `text`
`ms` `halign` `valign` `scale` `plane`	Frame time · left/center/right · top/middle/bottom · none/fit/stretch · anim/frame
`mode` `speed`	1–8 or static, left, right, up, down, snow, picture, laser · 0–255
`brightness` `power` `mirror` `synctime`	0–255 · on/off · on/off · 1

Link builder

Builds a link from the current Text tab, panel and Mode/Speed/Brightness settings.

Sign Disconnect when done Hide interface

Remembered signs

Signs this browser may reconnect to without the chooser (needs the Chrome flags described in the help text).