Proje Defteri Tools
Free online tools for Arduino, electronics, software and AI.
Everything runs in your browser, your data never leaves the page.
Electronics
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.
7-Segment Encoder
Generate 7-segment display byte codes (cathode/anode) for Arduino.
Arduino Pinout
Uno, Nano, Mega and ESP32 pin maps in a searchable table.
Resistor Color Code
Read 4, 5 and 6 band resistor values from color codes.
LCD Assistant — image2cpp
Convert images to byte arrays for monochrome displays.
LCD Character Generator
Design your own custom characters for LCD screens.
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.
AI
Generators
Which tool is missing?