How to migrate from STM32 to ESP32?

Migrating from STM32 (typically ARM Cortex-M) to ESP32 (Xtensa or RISC-V) involves transitioning between two powerful yet different microcontroller ecosystems. Here’s a tailored, step-by-step guide:

STM32 to ESP32 Migration Guide
1. Define Your Project Requirements
Ask yourself:

• Are you using Wi-Fi/Bluetooth? (ESP32 has built-in)
• What peripherals are critical? (ADC, PWM, UART, etc.)
• What are your real-time constraints?
• Will you use RTOS (e.g., FreeRTOS)?

2. Compare Hardware Features

3. Development Tools

4. Porting Code
GPIO Example
STM32:

c

HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5, GPIO_PIN_SET);

ESP32 (ESP-IDF):

c

gpio_set_level(GPIO_NUM_5, 1);

UART Example
STM32:

c

HAL_UART_Transmit(&huart1, buffer, len, HAL_MAX_DELAY);

ESP32:

c

uart_write_bytes(UART_NUM_1, buffer, len);

Timers / Delay

• STM32: HAL_Delay(1000);
• ESP32: vTaskDelay(pdMS_TO_TICKS(1000)); (FreeRTOS)

5. Hardware Adjustments

• Power: ESP32 operates at 3.3V; ensure level shifting if needed.
• Pinout: Map new GPIO numbers accordingly.
• Clock source: ESP32 has built-in oscillator; external crystal often optional.
• Flash boot mode: Remember ESP32 bootstrapping pins (e.g., GPIO0).

6. Wi-Fi/Bluetooth (if needed)
ESP32 brings wireless capabilities. Use:

c

#include "esp_wifi.h"
#include "esp_bt.h"

Set up via esp_wifi_init() and similar APIs.

7. Test and Debug

• Use UART for logging: esp_log_level_set(TAG, ESP_LOG_INFO);
• Use built-in debugger (JTAG via ESP-Prog) or serial console for debugging.

Summary Table

Suggested Next Steps

1. Install ESP-IDF or try Arduino IDE for easier transition.
2. Start with simple GPIO/UART examples.
3. Gradually port and test each module (timers, communication, etc.).
4. Use idf.py menuconfig to configure hardware like Wi-Fi, UARTs, and flash.