STM32F429 USART Communication with Arduino Uno

Posted on August 21, 2017 at 16:18

Hello. I am trying to perform usart communication between the stm32f429 discovery board and the arduino uno. I have tried both sending and receiving data with the stm board but it is not working. I am sharing the codes I have used for receiving data with the stm board. Any help would be appreciated.

STM:

&sharpinclude <stm32f4xx.h>

void led_init()

{

RCC ->AHB1ENR |= RCC_AHB1ENR_GPIOGEN; //Enables port G input output pins by setting the corresponding bit in advanced high performance bus 1 register.

GPIOG ->MODER |= GPIO_MODER_MODER13_0; //Configures pin 13 as a general purpose output pin by setting the corresponding bit in the mode register

GPIOG ->OTYPER &= ~(GPIO_OTYPER_OT_13); //Makes the output type as push-pull by resetting the corresponding bit in output type register.

GPIOG ->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR13_0;//Makes the output medium speed.

GPIOG ->PUPDR &= ~(GPIO_PUPDR_PUPDR13);//No pull up or pull down.

}

void usart_setup()

{

RCC ->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;

GPIOA->MODER |= GPIO_MODER_MODER3_1;

GPIOA->AFR[0] |= GPIO_AF7_USART2<<12;

RCC->APB1ENR |= RCC_APB1ENR_USART2EN;

USART2->CR1 |= USART_CR1_UE;

USART2->BRR |= 0x2580;

USART2->CR1 |= USART_CR1_RE;

}

char usart_read()

{

char ch;

while(!(USART2->SR & USART_SR_RXNE))

ch = USART2->DR;

return ch;

}

int main(void)

{

led_init();

usart_setup();

while(1)

{

GPIOG->BSRRH|=GPIO_BSRR_BS_13;

if(usart_read())

GPIOG->BSRRL|=GPIO_BSRR_BS_13;

}

}

Arduino:

&sharpinclude <SoftwareSerial.h>

int incoming = 0;

SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

mySerial.begin(9600);

}

void loop() {

mySerial.write('a');

}

As arduino uno runs on 5 volt logic, I am already using a level shifter between the stm board and the arduino.

Thanks

#usart #stm32 #arduino