embedwise.com

The embedded engineer's
calculator hub

Interactive calculators for firmware engineers. Instant register values, MCU presets, and real-world tolerances. No sign-up required.

5 live calculators
8 coming soon
4 MCU families
Free always

Protocol & Communication

Serial interfaces, timing, and bus configuration

UART Baud Rate

live

Calculate BRR/UBRR register values for STM32, nRF52, ESP32, and AVR. Shows actual baud rate and error %.

uart serial baud

I2C Pull-up Resistor

live

Calculate minimum and maximum pull-up resistor values for I2C based on VCC, bus speed, and total capacitance.

i2c pullup resistor

SPI Clock Divider

soon

Calculate prescaler values to achieve target SCLK frequency on STM32, nRF52, and ESP32.

CAN Bus Bit Timing

soon

Calculate BTR/NBTP register values, sample point %, and sync jump width for CAN and CAN-FD.

Passive Components

Resistors, capacitors, and fundamental circuits

Voltage Divider

live

Calculate Vout from R1/R2, find nearest E-series values, and see tolerance impact on the output.

voltage-divider resistor e24

RC Filter / Time Constant

soon

Calculate cutoff frequency, −3 dB point, and rise time for RC low-pass and high-pass filters.

LED Current Limiting Resistor

live

Calculate the series resistor for LEDs driven from a GPIO or supply rail, with Vf database for common LEDs.

led resistor gpio

Resistor Color Code

live

Decode 4-band, 5-band, and 6-band resistor color codes including tolerance and temperature coefficient.

resistor color-code 4-band

Power & Energy

Voltage regulators, power budgets, and battery life

LDO Voltage Regulator

soon

Calculate LDO dropout headroom, power dissipation, θJA requirements, and output capacitor stability.

Battery Life Estimator

soon

Estimate run time for IoT devices with sleep/active/TX current profiles. CR2032, LiPo, AA/AAA supported.

Firmware Tools

CRC, timers, watchdogs, and register values

PWM Timer / Prescaler

soon

Calculate prescaler and ARR/period register values for a target PWM frequency on STM32, nRF52, and RP2040.

CRC Calculator

soon

Generate and verify CRC-8, CRC-16, CRC-32 checksums for firmware data packets and flash validation.

Watchdog Timer

soon

Calculate IWDG/WWDG prescaler and reload register values for a target timeout on STM32 and nRF52.