SPI and I2C (Bare-Metal)

Purpose

Implement SPI and I2C master drivers for sensor and memory chips: clock configuration, phase/polarity (SPI), START/ACK sequences (I2C), and common register-oriented transaction patterns.

When to Use

• Reading an I2C sensor (WHO_AM_I register)
• SPI flash or display bring-up
• Debugging NACK or stuck SCL
• Replacing HAL_I2C/SPI with minimal code

Workflow

1. SPI master (STM32)