- Hacker Embedded STM32: How to use SPI Communication

STM32 HAL Tutorial: Interfacing SPI via polling and interrupt

Abstract

Learn how to configure SPI communication on STM32 using CubeMX and HAL drivers. Step-by-step guide to use SPI in polling, IT and DMA modes.

1. Introduction

In previous episodes, we explored I²C communication with sensors.
Now we’ll learn about SPI (Serial Peripheral Interface), a high-speed protocol often used for:

OLED or TFT displays
External EEPROM and flash memory
Sensors requiring fast data transfer

By the end of this episode, you’ll be able to:

Configure STM32 SPI peripheral using CubeMX.

2. Prerequisites

STM32 board with SPI pins exposed (SCK, MOSI, MISO, CS).
SPI device (e.g., OLED display SSD1306, or EEPROM like 25LC256).
STM32CubeIDE installed.

3. Configuring SPI in CubeMX

Step 1 – Open Project

Create a new project in STM32CubeMX.

Step 2 – Enable SPI Peripheral

Go to Pinout & Configuration.
Select SPI1 (or available SPI peripheral).
Assign pins for:
- SCK – Clock / PB3
- MOSI – Master Out, Slave In / PB5
- MISO – Master In, Slave Out / PB4
- CS – No pin will be used on the loop back demo.

Tip: For a simple demo, in case you don’t have external components, you can create a hardware loopback by connecting MOSI and MISO together:

Step 3 – Configure Parameters

Click SPI1 → Parameter Settings:
- Mode: Full-Duplex Master
- Data Size: 8 bits
- Clock Polarity/Phase: Check device datasheet (often CPOL = 0, CPHA = 0)
- Baud Rate Prescaler: Choose suitable speed – the Clock Configuration will impact the settings here, make sure to adjust your MCU’s frequency first

Step 4 – Enable NVIC Interrupt and DMA (Optional)

For the hands on, only SPI NVIC will be used

Step 5 – Generate Code

Click Project → Generate Code to initialize HAL SPI structures.

4. Sending/Receiving Data via SPI by polling

Example: Sending Multiple Byte

				
					/* USER CODE BEGIN PV */
uint8_t tx_buffer[10]={0,1,2,3,4,5,6,7,8,9};
uint8_t rx_buffer[10];
/* USER CODE END PV */

/* USER CODE BEGIN 2 */
HAL_SPI_TransmitReceive(&hspi1,tx_buffer,rx_buffer,10,100);
 /* USER CODE END 2 */

5. Sending/Receiving Data via SPI via IT

				
					/* USER CODE BEGIN PV */
uint8_t tx_buff[]={0,1,2,3,4,5,6,7,8,9};
uint8_t rx_buff[10];
/* USER CODE END PV*/

  /* USER CODE BEGIN 2 */
  HAL_SPI_TransmitReceive_IT(&hspi1,tx_buff,rx_buff,10);
  /* USER CODE END 2 */

/* USER CODE BEGIN 4 */
void HAL_SPI_TxRxCpltCallback(SPI_HandleTypeDef *hspi)
{
  HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_5);
}
/* USER CODE END 4 */

Full Source Code: hackerembedded/STM32_EP8

6. Compiling and Running

Build Project → Click hammer icon or press [Ctrl+B].
Flash Project → Connect STM32 and run or enter in Debug Mode.
Test SPI Communication:
1. Place a breakpoint on the callback or monitor the LED

7. Hands-On Lab Recap

You learned:

How to configure SPI peripheral in CubeMX.
How to send and receive data with SPI using HAL.
Basic HAL functions for full-duplex SPI communication.

SPI allows fast, reliable communication in embedded systems and is often used for displays, memory, and high-speed sensors.

8. Common Issues & Fixes

Issue	Cause	Solution
SPI device not responding	Wrong SCK/MOSI/MISO pins	Verify CubeMX pinout
Display garbled	Wrong clock polarity/phase	Check device datasheet
Transmission error	CS pin not handled	Set CS LOW before transmit, HIGH after
Compilation error	HAL_SPI functions missing	Regenerate CubeMX code

STM32: How to use SPI Communication