STM32 Bare-Metal Firmware & Driver Development

Welcome to this repository for bare-metal firmware development on STM32 (Cortex-M) microcontrollers. This project focuses on writing low-level drivers from scratch by directly manipulating registers and utilizing hardware structures without relying on HAL.

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Repository Contents & Features

The project is structured into progressive modules, moving from basic register manipulation to advanced interrupt-driven applications:

Core & Foundations

• chip_headers/CMSIS: Core Cortex-M hardware abstraction and register definitions.
• 0_led_toggle_addr & 1_led_toggle_addr_struct: Introduction to memory-mapped I/O and register structures.

General Purpose I/O (GPIO)

• 2_gpio_output & 3_gpio_bsrr: Configuring pins as outputs using standard registers.
• 4_gpio_input: Reading digital input signals.

Universal Asynchronous Receiver-Transmitter (UART)

• 5_uart_tx & 8_uart_rx: Basic polling-based serial transmission and reception.
• 6_uart_printf: Retargeting the standard printf() function to output over UART for easier debugging.
• 7_uart_modular: Clean, modular driver structure separating UART initialization and logic.
• 16_uart_rx_interrupt: Non-blocking asynchronous data reception using interrupts.

Analog-to-Digital Converter (ADC)

• 9_adc_single_conversion: Sampling an analog signal once on demand.
• 10_adc_continous_conversion: Continuous sampling modes for real-time signals.
• 17_adc_interrupt: Handling ADC conversion completions asynchronously.

Timers & System Tick (SysTick)

• 11_systick_delay & 18_systick_interrupt: ARM Cortex-M internal system tick timer for precise delays.
• 12_timers: Configuring hardware general-purpose timers.
• 13_OutputCompare & 14_InputCapture: Generating waveforms (PWM) and measuring external signal frequencies/pulse widths.
• 19_timers_interrupt & tim2_interrupt: Working with periodic timer-overflow interrupts.

Interrupt Handling (15_InputInterrupt)

• Using the Nested Vectored Interrupt Controller (NVIC) to manage external and internal peripheral triggers.

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Hardware Verification

• docs/: Relevant technical documentation, reference manuals, and datasheets.
• logic analyzer outputs/: Saved waveforms and timing captures verifying that the protocols (UART, Timers, PWM) match physical hardware specifications exactly.

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Tools & Environment

• Language: Embedded C
• Target Architecture: ARM Cortex-M4 (STM32)
• Development Flow: Direct register-level access (No HAL)