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Interactive embedded engineering calculators for firmware developers. Instant register values, MCU presets, and real-world tolerances. No sign-up required.
Calculate prescaler values to achieve target SCLK frequency on STM32, nRF52, and ESP32.
Calculate BTR/NBTP register values, sample point %, and sync jump width for CAN and CAN-FD.
Calculate cutoff frequency, −3 dB point, and rise time for RC low-pass and high-pass filters.
Calculate LDO dropout headroom, power dissipation, θJA requirements, and output capacitor stability.
Estimate run time for IoT devices with sleep/active/TX current profiles. CR2032, LiPo, AA/AAA supported.
Calculate prescaler and ARR/period register values for a target PWM frequency on STM32, nRF52, and RP2040.
Calculate IWDG/WWDG prescaler and reload register values for a target timeout on STM32 and nRF52.
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Designing embedded systems means working within tight constraints — bus speeds, voltage rails, timing budgets, register widths. Every decision has an exact number behind it, and getting it wrong costs debug time you don't have. The wrong pull-up resistor introduces I2C glitches at 400 kHz. An incorrect baud rate register causes UART framing errors under noise. An oversized LED current reduces component lifetime. These aren't guesses — they're math.
Embedwise provides a free, open-source collection of interactive embedded engineering calculators that run entirely in the browser. No account, no server round-trip, no data leaving your machine. Results update instantly as you type.
Protocol & communication: UART baud rate register values (BRR for STM32, UBRR for AVR, prescaler for ESP32), I2C pull-up resistor selection based on bus speed and capacitance, NMEA 0183 checksum validation, and u-blox UBX protocol CK_A/CK_B checksum generation.
Passive components: Voltage divider output with E24/E96 nearest standard values and tolerance analysis, LED current-limiting resistor with forward voltage database, and resistor color code decoder for 4-, 5-, and 6-band resistors.
Firmware tools: CRC-8, CRC-16, and CRC-32 checksum generation for data packet validation, PWM timer prescaler and ARR register values for target frequencies, and watchdog timer configuration for IWDG/WWDG peripherals.
Select a calculator from the grid above. Each tool accepts your circuit parameters and returns the exact value — register hex, resistor ohms, current milliamps — along with an error or accuracy indicator. For MCU-specific tools, choose your target device from the preset dropdown to get the correct register name and formula. You can override the clock frequency for non-standard PLL configurations.
Each calculator page includes a brief technical explainer covering the underlying math, a C code snippet, common mistakes, and a quick reference table for typical configurations. All calculators support mobile — useful when you're at the bench with a phone and a multimeter.
MCU presets currently cover STM32 (F4, F1, L4), nRF52 (nRF52840, nRF52832), ESP32, AVR (ATmega328, ATmega2560), and RP2040. Additional families and peripherals are added regularly.