stm32h7-freqcounter

A frequency counter for the NUCLEO-STM32H743

Usage details

• UART: 8N1, 115200 baud/s
• Processor frequency: 400 MHz
• Measurement resolution (theoretical): 2.5ns

Pinout

• PD8 --> USART3_TX (default for Nucleo)
• PC10 (opposite of NRST) --> counter input

OLED pinout (optional)

Tested OLED: SSD1306 (4-wire SPI)

• 3.3V --> VCC
• GND --> GND
• PB3 (opposite of D10) --> SCK/D0
• PB5 (opposite of D11) --> MOSI/D1
• PF12 (D8) --> RESET
• PD15 (D9) --> DC (Data/Command)
• PB12 (opposite of GND) --> CS/NSS (Negative Slave Select)

Sample output

• PC9 (opposite of IOREF) --> 200 MHz (MCO - Master Clock Output)

Nucleo pinout

https://www.st.com/content/ccc/resource/technical/document/user_manual/group0/26/49/90/2e/33/0d/4a/da/DM00244518/files/DM00244518.pdf/jcr:content/translations/en.DM00244518.pdf, page 33