MMM-Blynk

A module for MagicMirror² that displays Blynk IoT virtual pin (datastream) values from one or more devices.

Each Blynk device has its own auth token, so this module reads from every device you list and shows their pins together. Values are fetched server-side by the node helper through the Blynk HTTPS API, which avoids browser CORS issues and keeps your tokens out of the front-end.

Blynk version: This module targets Blynk IoT (Blynk 2.0 / blynk.cloud). The legacy Blynk 0.1 cloud (blynk-cloud.com) is shut down and is not supported. If you self-host the legacy server its API differs and will not work here.

Screenshot

Installation

Clone (or copy) this folder into your MagicMirror modules directory. The folder must be named MMM-Blynk:

cd ~/MagicMirror/modules
git clone kritch83/MMM-Blynk

No runtime dependencies are required (the module uses Node's built-in fetch, available in Node 18+, which MagicMirror already requires).

Developer commands

• npm install — install devDependencies (ESLint).
• npm run lint — run lint / formatter checks.
• npm run lint:fix — auto-fix lint / formatting issues.

Update

cd ~/MagicMirror/modules/MMM-Blynk
git pull

Prerequisites

For each device you want to show, from the Blynk Console:

1. Create the datastreams (virtual pins, e.g. V0, V1) your firmware writes to.
2. Open the device → Device Info and copy its AuthToken.
3. Note your server region (top-left of the console, e.g. fra1.blynk.cloud, ny3.blynk.cloud, sgp1.blynk.cloud, lon1.blynk.cloud). The generic blynk.cloud also works but a regional host is slightly faster.

Configuration

Add a configuration block to the modules array in config/config.js.

Example configuration

{
  module: "MMM-Blynk",
  position: "top_right",
  header: "Blynk",
  config: {
    server: "blynk.cloud",
    updateInterval: 60 * 1000,  // seconds
    devices: [
      {
        name: "Greenhouse", // name of device for header, doesn't need to match blynk.cloud name
        token: "YourDeviceAuthToken",  // auth token of device
        pins: [
          { pin: "V0", label: "Temperature", unit: "°C", decimals: 1, icon: "fa-temperature-half" },
          { pin: "V1", label: "Humidity", unit: "%", decimals: 0, icon: "fa-droplet" }
        ]
      },
      {
        name: "Garage",
        token: "AnotherDeviceAuthToken",
        // server: "ny3.blynk.cloud", // optional per-device override
        pins: [
          { pin: "V5", label: "Door", icon: "fa-warehouse", map: { "0": "Closed", "1": "Open" } }
        ]
      }
    ]
  }
}

Module options

Option	Type	Default	Description
server	string	"blynk.cloud"	Default Blynk server host. Can be overridden per device.
title	string	""	Optional header text. If empty, the standard header config field is used.
updateInterval	number	60000	How often to poll Blynk, in ms.
animationSpeed	number	500	DOM fade speed on update, in ms.
initialLoadDelay	number	0	Delay before the first poll, in ms.
fontSize	string	"small"	One of MagicMirror's sizes: xsmall, small, medium, large, xlarge.
showDeviceName	boolean	true	Show a header row with each device's name.
showDeviceStatus	boolean	true	Show an online/offline dot. Adds one extra request per device per poll.
showIcons	boolean	true	Render per-pin Font Awesome icons when a pin defines icon.
naText	string	"N/A"	Text shown when a pin has no stored value.
rotate	boolean	false	Show one slide at a time (Compliments-style) instead of the full table.
rotateInterval	number	10000	ms each slide stays on screen. Only used when rotate: true.
rotateBy	string	"pin"	"pin" = one reading per slide; "device" = one device (all pins) per slide.
rotateRandom	boolean	false	Pick the next slide at random instead of in order.
devices	array	[]	The list of devices to read. See below.

Device options (each entry in devices)

Option	Type	Required	Description
name	string	no	Label shown above the device's pins. Defaults to "Device".
token	string	yes	The device AuthToken from Blynk → Device Info.
server	string	no	Per-device server host override (defaults to the module server).
pins	array	yes	The datastreams to display. See below.

Pin options (each entry in a device's pins)

Option	Type	Required	Description
pin	string	yes	Virtual pin / datastream, e.g. "V0" (case-insensitive).
label	string	no	Display label. Defaults to the pin name.
unit	string	no	Appended verbatim after the value. Include a leading space if you want one (" W").
decimals	number	no	Round numeric values to this many decimal places.
icon	string	no	A Font Awesome class, e.g. "fa-temperature-half".
map	object	no	Map raw values to text, e.g. { "0": "Closed", "1": "Open" }. Matched as strings.

Rotating display

By default every device and pin is shown together in a table. Set rotate: true to instead cycle through one item at a time, fading between them like the default Compliments module — handy for a small or center region. Each slide shows for rotateInterval ms and fades using animationSpeed.

{
  module: "MMM-Blynk",
  position: "top_center",
  config: {
    rotate: true,
    rotateInterval: 10 * 1000,
    rotateBy: "pin", // or "device"
    devices: [ /* … same as above … */ ]
  }
}

• rotateBy: "pin" (default) shows the device name, the value (enlarged), and the label, one reading per slide.
• rotateBy: "device" shows one device and all of its pins per slide.
• rotateRandom: true picks the next slide at random instead of cycling in order.

How it works

• For each device, the node helper makes one request for all of that device's pins (/external/api/get?token=…&V0&V1) and, if showDeviceStatus is on, one request to /external/api/isHardwareConnected.
• A failing device (bad token, network error) shows an inline error and does not blank the others.
• Keep updateInterval reasonable (the default 60s is plenty for a wall display) to stay within Blynk's HTTP API rate limits.