Carry the Arduino World in Your Pocket
Projects, components, electronics tools and new IoT: control ESP32 and Pico W boards from your phone. Start free, go Premium to remove the limits.
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What Can You Do?
Push the boundaries of the electronics world with BlueGrays.
Rich Project Library
Explore Arduino and electronics projects. Learn step by step with circuit diagrams, code, and build videos.
Electronics tools
Color code · LED resistor · Ohm's law
Pinout
Interactive pinouts of 10 boards: analog, PWM, I2C, SPI and UART pins with board-specific code samples and warnings.
Electronic Components Database
Sensors, boards, motors — hundreds of components and the projects they're used in.
What shall we build today?
Find the right project in 3 questions.
Find a projectCommunity Forum
Ask questions, share ideas, solve problems together.
Control your board from your phone
Switch on a lamp, watch the room temperature or water your plants with an ESP32 or Raspberry Pi Pico W. There are 8 ready-made templates, and Ohmi prepares the code.
- Relay lamp
- Temperature and humidity
- Room station
- RGB LED strip
- Door / window
- Soil moisture + pump
- Motion detector
- Servo curtain
Your first device is free
The free plan includes 1 device, 1 chart and 24 hours of history. Premium adds more devices, more charts and longer history.
Arduino library: Open the Library Manager in the Arduino IDE, search for BlueGraysIoT and install it.
Pick your board, find your project
Projects made for the board you have, with circuit diagrams and code.
Discover Arduino Projects
Hundreds of projects from beginner to advanced — schematics, code, and videos.
Electronics tools
The calculations and tables you need most while building circuits, in one place. Runs in your browser and gives the same results as the app.
Electronics guides
Get to know the parts, choose the right board and build your projects with confidence.
ComponentsINMP441 ESP32 I2S Microphone: Read Audio, Measure dB, Plot
Learn to wire the INMP441 digital MEMS microphone to an ESP32, read 24-bit audio over I2S, calculate ambient noise in dB, plot the waveform in Serial Plotter, use it with a Pico, and see how it differs from the KY-038.
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GuidesJingle Bells Arduino Code: 4 Christmas Songs for a Buzzer
Build a music box that plays four Christmas songs with a passive buzzer, two LEDs and a button: accurate note frequencies, tempo maths, a millis-based LED player, an ESP32 touch card and a Pico MicroPython version.
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BasicsResistor Color Code: How to Read 4, 5 and 6 Band Resistors
Learn to read the colored bands on resistors in seconds: the color-value chart, 4, 5 and 6 band reading, which end to start from, common 220 Ω, 1 kΩ and 10 kΩ colors, checking with a multimeter and a simple Arduino ohmmeter.
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Electronic Components Database
Sensors, boards, motors — hundreds of components and the projects they're used in.
Get Started Now
Download the BlueGrays app and bring your Arduino projects to life.
- 01Discover Arduino ProjectsBrowse projects from beginner to advanced. Each project includes step-by-step circuit diagrams, source code, video tutorials, and a full list of required components.
- 02Complete Component DatabaseExplore 100+ electronic components with detailed specifications, pin diagrams, and usage examples. See which components you've used and add them to your workshop.
- 03Workshop & Achievement SystemManage your component inventory, get smart project recommendations based on parts you own, and earn badges as you level up your maker skills.
