STM32F4-Discovery resets

[timon1994]

Posted on June 22, 2012 at 12:29

I've wiredSTM32F4-Discovery board and USB<->UART and wrote a little program that prints ''r'' in the main function.

There's the initialization code for USART. In terminal I can see letter ''r'' coming every half second. It means thatSTM32F4 resets every half second. What can I do?

GPIO_InitTypeDef GPIO_InitStructure;

USART_InitTypeDef USART_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);

USART_InitStructure.USART_BaudRate = 115200;

USART_InitStructure.USART_WordLength = USART_WordLength_8b;

USART_InitStructure.USART_StopBits = USART_StopBits_1;

USART_InitStructure.USART_Parity = USART_Parity_No ;

USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

USART_Init(USART2, &USART_InitStructure);

USART_Cmd(USART2, ENABLE);

GPIO_InitTypeDef GPIO_InitStructure;

USART_InitTypeDef USART_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2); GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2); USART_InitStructure.USART_BaudRate = 115200; USART_InitStructure.USART_WordLength = USART_WordLength_8b; USART_InitStructure.USART_StopBits = USART_StopBits_1; USART_InitStructure.USART_Parity = USART_Parity_No ; USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; USART_Init(USART2, &USART_InitStructure); USART_Cmd(USART2, ENABLE GPIO_InitTypeDef GPIO_InitStructure; USART_InitTypeDef USART_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2); GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2); USART_InitStructure.USART_BaudRate = 115200; USART_InitStructure.USART_WordLength = USART_WordLength_8b; USART_InitStructure.USART_StopBits = USART_StopBits_1; USART_InitStructure.USART_Parity = USART_Parity_No ; USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; USART_Init(USART2, &USART_InitStructure); USART_Cmd(USART2, ENABLE);

[Tesla DeLorean]

Posted on June 22, 2012 at 13:28

Try looking elsewhere, this code doesn't seem to be problematic. The PA2 and PA3 pins should be free to use.

Get a scope, check the power supply isn't browning out, check the reset pin, make sure you don't have any watchdogs, or unserviced interrupts.

[Andrew Neil]

Posted on June 23, 2012 at 15:13

''It means that STM32F4 resets every half second''

Or that you let your code run off the end of the main() function...''What can I do?'' Connect your debugger, and see what's happening! Nobody else can help without seeing your code!

[Tesla DeLorean]

Posted on June 23, 2012 at 15:35

Another potential failure mode could be an inadequate stack allocation for the functions and libraries being used. The eval examples have very small stacks perhaps 128 or 1024 bytes. Things like scanf/printf have large footprints.

[frankmeyer9]

Posted on June 24, 2012 at 12:57

And, check that you did not configure an obvious source of a reset - a watchdog.

[timon1994]

Posted on June 26, 2012 at 12:36

Solved it!

The problem was in empty cycle in main function. Watchdog reseted the controller. I've added IWDG_ReloadCounter() there and it works ok. Thank you!