Free Maker Tools

Pinouts and calculators for ESP32, Arduino, Raspberry Pi and robot builders, straight from the TechsPassion workbench. Free, no sign-up, and they work on your phone.

Pinouts

A tap-able pin diagram for every board, what each pin does, and the gotchas that stop beginner projects.

ESP32 DevKit V1

3.3 V logic — NOT 5 V tolerant

ESP32-S3

3.3 V logic — NOT 5 V tolerant

Arduino Uno R3

5 V logic

Arduino Nano

5 V logic

NodeMCU ESP8266

3.3 V logic

ESP32-C3 SuperMini

3.3 V logic — NOT 5 V tolerant

Raspberry Pi Pico / Pico W

3.3 V logic — NOT 5 V tolerant

Raspberry Pi 40-pin GPIO

3.3 V logic — NOT 5 V tolerant, no analog inputs

Designer

Arduino UNO R4 WiFi

LED Matrix Designer

Draw on the 12×8 LED matrix with your mouse or finger, pick a preset or invert it, then copy a ready-to-upload Arduino sketch.

Open the designer

Calculators

Ohm's Law

Voltage, current, resistance and power.

LED Resistor

Series resistor, standard value and color bands.

Resistor Color Code

Decode 4 and 5 band resistors.

Capacitor Code

104 = 100 nF, plus RC timing.

Voltage Divider

Vout, or solve for R1 (5 V to 3.3 V).

Battery Life

Runtime, incl. ESP32 deep sleep.

ADC to Voltage

Raw analogRead() to volts.

Servo & PCA9685

Angle to pulse, PCA9685 ticks, power.

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Educational use only. All tools are provided "as is" without warranty. Always check your part's datasheet. See the full disclaimer.