Proje Defteri Tools
Free online tools for Arduino, electronics, software and AI.
Everything runs in your browser, your data never leaves the page.
Calculators
Ohm's Law Calculator
Solve voltage, current, resistance and power from any two.
LED Resistor Calculator
Find the series resistor and power rating for any LED.
Voltage Divider Calculator
Compute output voltage (Vout), current and power from Vin, R1 and R2.
555 Timer Calculator
Astable/monostable frequency, period and duty cycle.
Capacitor Code Calculator
Decode ceramic capacitor codes (104 = 100nF) to pF/nF/µF.
Series/Parallel Resistor
Compute series and parallel equivalents of several resistors.
Resistor Color Code
Read 4, 5 and 6 band resistor values from color codes.
Battery Life Calculator
Estimate runtime from battery capacity (mAh) and current draw.
RC / LC Filter Calculator
Compute the cutoff or resonant frequency of RC and LC filters.
Displays
LCD Assistant - image2cpp
Convert images to byte arrays for monochrome displays.
LCD Character Generator
Design your own custom characters for LCD screens.
I2C LCD Code Generator
Generate ready LiquidCrystal_I2C code for Arduino I2C LCDs.
7-Segment Encoder
Generate 7-segment display byte codes (cathode/anode) for Arduino.
Sensors & Arduino
HC-SR04 Code Generator
Generate ready code for the Arduino ultrasonic distance sensor.
DHT11/DHT22 Code Generator
Generate ready DHT code for the Arduino temperature/humidity sensor.
Arduino Pinout
Uno, Nano, Mega and ESP32 pin maps in a searchable table.
ESP32 Pinout
Clickable GPIO map for DevKit v1, 38-pin, C3 SuperMini, S3, C3, S2, C6 with ADC, touch, I2C, SPI filters.
Developer
JSON Formatter & Validator
Beautify, minify and validate JSON with error locations.
Base64 Encode / Decode
Encode or decode text to Base64 (UTF-8 safe, URL-safe option).
JWT Decoder
Decode JWT header and payload entirely in your browser.
Two Text Diff
Compare two texts and highlight the differences.
Markdown Live Preview
Instantly see your Markdown rendered as HTML.
Number Base Converter
Convert between binary, octal, decimal and hex instantly.
Color Converter
Convert between HEX, RGB and HSL color codes.
Unix Timestamp Converter
Convert Unix timestamps to dates and back, both directions.
Regex Tester
Test regular expressions live with match and group highlighting.
Cron Expression Generator
Explain a cron expression and see the next run times.
AI
Generators
Which tool is missing?