Posted on February 15, 2013 at 22:22Hello,
I can't seems to get USART2 to work.There is nothing in TX (PA2) & RX(PA3) Pin when view with a logic analyzer.I think I am missing something in my code..I need help.
#include ''stm32f10x.h''
#include <stdio.h>
void Init_SysClock(void);
void Init_RCC(void);
void Init_USART(void);
void USART_PutChar(uint8_t ch);
void USART_PutString(uint8_t * str);
uint8_t text [] = ''STM32VLDISCOVERY tutorial\n\rhttp://en.radzio.dxp.pl/stm32vldiscovery/\n\r\n\r'';
int main(void)
{
vu32 dly;
Init_SysClock(); //Initialize GPIO & Peripherals Clocks
Init_RCC(); //Initialize GPIO
Init_USART();
while(1)
{
USART_PutString(text);
for(dly = 0; dly < 1000000; dly++);
}
}
void USART_PutChar(uint8_t ch)
{
while(!(USART2->SR & USART_SR_TXE));
USART2->DR = ch;
}
void USART_PutString(uint8_t * str)
{
while(*str != 0)
{
USART_PutChar(*str);
str++;
}
}
//USART2_TX=> PA2 | USART2_RX=> PA3
void Init_USART(void)
{
//Enable USART, TX & RX
USART2->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
USART2->BRR = (PCLK / 9600); //Baud Rate = 9600kps
}
void Init_SysClock(void)
{
/*Enable Alternate Function,GPIOA,GPIOB,GPIOC, GPIOD & TIMER1, ADC1 & ADC2 Clock Clock*/
RCC->APB2ENR |= RCC_APB2ENR_AFIOEN | RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPBEN |
RCC_APB2ENR_IOPCEN | RCC_APB2ENR_IOPDEN | RCC_APB2ENR_TIM1EN |
RCC_APB2ENR_ADC1EN | RCC_APB2ENR_ADC2EN;
/*Enable TIMER2, TIMER3,I2C1 & USART2 Clock*/
RCC->APB1ENR |= RCC_APB1ENR_TIM2EN | RCC_APB1ENR_TIM3EN |RCC_APB1ENR_I2C1EN |
RCC_APB1ENR_TIM4EN | RCC_APB1ENR_USART2EN;
RCC->AHBENR = RCC_AHBENR_DMA1EN ; //DMA1 clock enable
}
void Init_RCC(void)
{
//PARTIAL REMAP TIM1=>CH1/PA8,CH2/PA9,CH3/PA10,CH4/PA11,CH1N/PA7,CH2N/PB0,CH3N/PB1
AFIO->MAPR |= AFIO_MAPR_TIM1_REMAP_PARTIALREMAP | AFIO_MAPR_TIM2_REMAP |
AFIO_MAPR_USART1_REMAP ; //REMAP USART1=>TX/PB6,RXPB7
//PA2, PA7 Alternate Function Push Pull Output | PA0, PA3 Input Floating
GPIOA->CRL = 0xA4444B44;
GPIOA->CRH = 0x4444AAAA; //PA8 - PA11 Alternate Function Push Pull Output
//PB0 & PB1 =>Alt Function Push Pull O/P | PB6-PB7 Alt Function Open Drain
GPIOB->CRL = 0xFF4444AA;
GPIOB->CRH = 0x44444433; //Configure PB8 & PB9 as Output (Push Pull)
GPIOC->CRL = 0x44440000; //GPIOC0- GPIOC3 Analog Input
}
Regards
Slim
