1. PRJ2UC: Microcontrollers
workshop 3
Std. Periph.
Driver Lib.

2. Today
Standard Peripheral Driver Library
Blinky with STM32F0-Discovery LED & PB functions
USART with Std. Periph. Driver Lib.

3. Standard Peripheral Drivers Library
Today
Standard Peripheral Drivers Library
Blinky with STM32F0-Discovery LED & PB functions
USART with Std. Periph. Driver Lib.

4. Cortex Microcontroller Software Interface Standard (CMSIS)
SRAM
main application
USART
GPIO
???
drivers
CMSIS
STM32F05x Processor & Peripherals

5. Standard Peripheral Drivers Library
SRAM
main application
STM32F0-Discovery
LED & PB functions
STM Std Periph Lib
GPIO
STM Std Periph Lib
MISC
STM Std Periph Lib
RCC
STM Std Periph Lib
SYSCFG
STM Std Periph Lib EXTI
CMSIS
STM32F05x Processor & Peripherals

6. Today
Standard Peripheral Drivers Library
Blinky with STM32F0-Discovery LED & PB functions
USART with Std. Periph. Driver Lib.

7. Two files: STM32F0 LED & PB functions stm32f0-discovery.c
stm32f0-discovery.h

8. STM32F0 LED & PB functions typedef enum { LED3 = 0, LED4 = 1
STM32F0_DISCOVERY_LOW_LEVEL_Exported_Types */
typedef enum {
LED3 = 0,
LED4 = 1
} Led_TypeDef;
STM32F0_DISCOVERY_LOW_LEVEL_Exported_Functions
void STM_EVAL_LEDInit(Led_TypeDef Led);
void STM_EVAL_LEDOn(Led_TypeDef Led);
void STM_EVAL_LEDOff(Led_TypeDef Led);
void STM_EVAL_LEDToggle(Led_TypeDef Led);
void STM_EVAL_PBInit(Button_TypeDef Button,
ButtonMode_TypeDef Button_Mode);
uint32_t STM_EVAL_PBGetState(Button_TypeDef Button);

9. STM32F0 LED & PB functions - example
#include "stm32f0xx.h" #include "stm32f0_discovery.h" int main(void) { // Configure LED3 on STM32F0-Discovery STM_EVAL_LEDInit(LED3); while(1) STM_EVAL_LEDToggle(LED3); delay(SystemCoreClock/8); // Delay 1 sec. }

10. Standard Peripheral Drivers Library
SRAM
main application
STM32F0
LED & PB functions
STM Std Periph Lib
GPIO
STM Std Periph Lib
MISC
STM Std Periph Lib
RCC
STM Std Periph Lib
SYSCFG
STM Std Periph Lib EXTI
CMSIS
STM32F05x Processor & Peripherals

11. StdLib. is used in stm32f0_discovery.c
/* Configures LED GPIO */ void STM_EVAL_LEDInit( Led_TypeDef Led ) { GPIO_InitTypeDef GPIO_InitStructure; /* Enable the GPIO_LED Clock */ RCC_AHBPeriphClockCmd( GPIO_CLK[Led], ENABLE ); /* Configure the GPIO_LED pin */ GPIO_InitStructure.GPIO_Pin = GPIO_PIN[Led]; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIO_PORT[Led], &GPIO_InitStructure); }
General use of StdLib.:
1. Declare peripheral
specific struct(s)
2. Fill the struct(s)
with parameters
3. Call function(s)
with struct(s) as
a parameter

12. GPIO stm32f0xx_gpio.c
stm32f0xx_gpio.c ================================================================= ##### How to use this driver ##### ================================================================= [..] (#) Enable the GPIO AHB clock using RCC_AHBPeriphClockCmd() (#) Configure the GPIO pin(s) using GPIO_Init() Four possible configuration are available for each pin: (++) Input: Floating, Pull-up, Pull-down. (++) Output: Push-Pull (Pull-up, Pull-down or no Pull) Open Drain (Pull-up, Pull-down or no Pull). In output mode, the speed is configurable: Low, Medium, Fast orHigh. (++) Alternate Function: Push-Pull (Pull-up, Pull-down or no Pull) (++) Analog: required mode when a pin is to be used as ADC channel, DAC output or comparator input. (#) Peripherals alternate function: …

13. Assignment
Use STM_EVAL_PBGetState() to toggle the blue LED each time the blue Push Button is pressed. Remember to first initialize the pushbutton.
Change the 'STM32F0Discovery LED & PB functions' so that besides using LED3 and LED4 (see Led_TypeDef in stm32f0_discovery.h) to select a LED, you can also use LED_GREEN and LED_BLUE. E.g.: STM_EVAL_LEDToggle(LED_GREEN);

14. Assignment – extra
Add a new red LED to the 'STM32F0Discovery LED & PB functions' (see files stm32f0_discovery.h and stm32f0_discovery.c):
The LED is connected to PB0.
The LED is defined as LED5 (and/or as LED_RED).
The LED is on with a logic 1.
Test your implementation (remember to use a resistor in series) using the following function calls:
STM_EVAL_LEDInit(LED5);
STM_EVAL_LEDOn(LED5);
STM_EVAL_LEDOff(LED5);
STM_EVAL_LEDToggle(LED5);

15. Today
Standard Peripheral Drivers Library
Blinky with STM32F0-Discovery LED & PB functions
USART with Std. Periph. Driver Lib.

16. USART stm32f0xx_usart.c
stm32f0xx_usart.c ================================================================= ##### How to use this driver ##### ================================================================= [..] (#) Enable peripheral clock using RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE) function for USART1 or using RCC_APB1PeriphClockCmd(RCC_APB1Periph_USARTx, ENABLE) function for USART2 and USART3. (#) According to the USART mode, enable the GPIO clocks using RCC_AHBPeriphClockCmd() function. (The I/O can be TX, RX, CTS, or and SCLK). (#) Peripheral's alternate function: (++) Connect the pin to the desired peripherals' Alternate Function (AF) using GPIO_PinAFConfig() function. (++) Configure the desired pin in alternate function by: GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AF. (++) Select the type, pull-up/pull-down and output speed via GPIO_PuPd, GPIO_OType and GPIO_Speed members. (++) Call GPIO_Init() function. (#) Program the Baud Rate, Word Length , Stop Bit, Parity, Hardware flow control and Mode(Receiver/Transmitter) using the SPI_Init() function. (#) For synchronous mode, enable the clock and program the polarity, phase and last bit using the USART_ClockInit() function. (#) Enable the NVIC and the corresponding interrupt using the function USART_ITConfig() if you need to use interrupt mode. (#) When using the DMA mode: (++) Configure the DMA using DMA_Init() function. (++) Active the needed channel Request using USART_DMACmd() function. (#) Enable the USART using the USART_Cmd() function. (#) Enable the DMA using the DMA_Cmd() function, when using DMA mode.

17. USART (I)
int main(void) { GPIO_InitTypeDef GPIO_InitStructure; USART_InitTypeDef USART_InitStructure; uint16_t c; // Initialize USART1 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE); // Setup Tx- and Rx pin GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_1); GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_1); 1. 2. 3.

18. USART (II)
//fill with default values USART_StructInit(&USART_InitStructure); USART_InitStructure.USART_BaudRate = ; USART_Init(USART1, &USART_InitStructure); USART_Cmd(USART1, ENABLE); while(1) { // Transmit information: "Press a key: " while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET){} USART_SendData(USART1, 'P'); // Etc. ... // Receive data while(USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET){} c = USART_ReceiveData(USART1); 2. 3.

19. Use the example project to: Implement the following functions:
Assignment
Use the example project to:
Implement the following functions:
void USART_SendString(USART_TypeDef* USARTx, char *p);
void USART_ReceiveString(USART_TypeDef* USARTx, char *p);
Extra
Implement auto baud rate detection. Check the peripheral driver library for functions that can be used with respect to this feature.

20. Assignment: Use Std. Periph. Driver Library
Demonstrate next week per team:
TIP: Use interrupts for pushbutton (and USART?)
STM_EVAL_PBInit(BUTTON_USER, BUTTON_MODE_EXTI);
Putty
STM32F0-Discovery
“blue on”
Blue LED on
“blue off”
Blue LED off
“blue toggle”
Blue LED toggle
“green n” with n=1..9
Green LED blink with n Hz
STM32F0-Discovery
Putty
Blue pushbutton pressed
“Blue pushbutton pressed”