[STM32F4-Discovery] UART4 Problem

[regiuliano2009]

Posted on February 24, 2012 at 12:36

Hi all,

I'm searching to get work my UART4 port on my Discovery. I used the USART HyperTerminal_Interrupt example on stdPerif_example and I adapted to DISCOVERY. I see by some LedOn on the program that UART is working and sending interrupt. I manage to have a virtual USB-UART port with UM232R Ftdi but on my Putty nothing appeared I post my code   /* USARTx configuration ------------------------------------------------------*/   /* USARTx configured as follow:         - BaudRate = 9600 baud         - Word Length = 8 Bits         - Two Stop Bit         - Odd parity         - Hardware flow control disabled (RTS and CTS signals)         - Receive and transmit enabled   */   USART_InitStructure.USART_BaudRate = 9600;   USART_InitStructure.USART_WordLength = USART_WordLength_8b;   USART_InitStructure.USART_StopBits = USART_StopBits_2;   USART_InitStructure.USART_Parity = USART_Parity_Odd;   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;       USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;   STM_EVAL_COMInit(&USART_InitStructure); Function void STM_EVAL_COMInit(USART_InitTypeDef* USART_InitStruct) {   GPIO_InitTypeDef GPIO_InitStructure;   /* Enable GPIO clock */   //RCC_AHB1PeriphClockCmd(UART4_TX_PIN | UART4_RX_PIN, ENABLE);   RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); //clock a PORTC   RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE); //clock alla UART4!   /* Connect PXx to USARTx_Tx*/   GPIO_PinAFConfig(GPIOC, GPIO_Pin_10, GPIO_AF_UART4);   /* Connect PXx to USARTx_Rx*/   GPIO_PinAFConfig( GPIOC, GPIO_Pin_11, GPIO_AF_UART4);   /* Configure USART Tx as alternate function  */   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_10;   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;   GPIO_Init(GPIOC, &GPIO_InitStructure);   /* Configure USART Rx as alternate function  */   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;   GPIO_Init(GPIOC, &GPIO_InitStructure);   /* USART configuration */   USART_Init(UART4, USART_InitStruct);   /* Enable USART */   USART_Cmd(UART4, ENABLE); } I also add void UART4_IRQHandler(void); to _it.h to manage interrupt _it.c void UART4_IRQHandler(void) {     if(USART_GetITStatus(UART4, USART_IT_RXNE) != RESET)   {          GPIO_SetBits(GPIOD, GPIO_Pin_14); // accende led     /* Read one byte from the receive data register */     RxBuffer[RxCounter++] = (USART_ReceiveData(UART4) & 0x7F);     if(RxCounter == NbrOfDataToRead)     {       /* Disable the UART4 Receive interrupt */       USART_ITConfig(UART4, USART_IT_RXNE, DISABLE);     }   }   if(USART_GetITStatus(UART4, USART_IT_TXE) != RESET)   {       GPIO_SetBits(GPIOD, GPIO_Pin_13); // accende led       /* Write one byte to the transmit data register */     USART_SendData(UART4, TxBuffer[TxCounter++]);     if(TxCounter == NbrOfDataToTransfer)     {       /* Disable the UART4 Transmit interrupt */       USART_ITConfig(UART4, USART_IT_TXE, DISABLE);     }   } } Where I'm failing? THanks #uart/usart-parity-and-wordlengt

[Tesla DeLorean]

Posted on February 24, 2012 at 13:07

GPIO_PinAFConfig(GPIOC, GPIO_PinSource_10, GPIO_AF_UART4);

GPIO_PinAFConfig( GPIOC, GPIO_PinSource_11, GPIO_AF_UART4);

[regiuliano2009]

Posted on February 24, 2012 at 14:58

YeP works!!!

Thanks clive1!!!! U save the daY!!! (to be precise is GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_UART4); GPIO_PinAFConfig( GPIOC, GPIO_PinSource11, GPIO_AF_UART4); without underscore) I see by Putty some data steam appearing but It's not the welcome message... uint8_t TxBuffer[] = ''\n\rUSART Hyperterminal Interrupts Example: USART-Hyperterminal\  communication using Interrupt\n\r''; Is the problem that DATA is uint16 and data uint8??

void USART_SendData ( *  USARTx,

uint16_t  Data 

)

or have I to configure putty in another way? That's what I see: àøüpÿÿàpÇüààþüüààðüààðü~üàü~àüüàÇàü~Àüààðàðüüüüüðüàüÿüü~üüààþüàüpÿÿàpÇüàþüüààðüààðü~üàü~àüüàüüüü~Çü~Çüüðü~üüüüüüàü~àüü~øüÇàü~ÿàüàÇàü~Àüààðàðüüüüàø translation ISO-8859-1:1998 (Latin-1, West Europe) Thanks in advance

[Tesla DeLorean]

Posted on February 24, 2012 at 16:01

Sorry working from memory. PinSource uses an index, Pin uses a mask.

You might want to check the ODD parity setting, that would give you weird characters if the terminal is configured for 8N1.

[regiuliano2009]

Posted on February 24, 2012 at 16:19

no problem clive1 for pinsource

back to problem, If I try to send ''a''  (TXBuffer[]=''a'') the response to terminal is ü     what's wrong? I double checked and  my configuration is   /* USARTx configured as follow:         - BaudRate = 9600 baud         - Word Length = 8 Bits         - Two Stop Bit         - Odd parity         - Hardware flow control disabled (RTS and CTS signals)         - Receive and transmit enabled I can't understand

[regiuliano2009]

Posted on February 24, 2012 at 16:40

then if I send ''ab'' the response is

üpÀü ?

[Tesla DeLorean]

Posted on February 24, 2012 at 16:54

If it's not the 8O2 rather than 8N1, then perhaps the baud rate is set up wrong.

Consider how the code is being compiled. The STM32F4-Discovery board has a different crystal speed for HSE than the library default. I think you want 8 MHz, not 25 MHz. Check the crystal speed in the IDE, and the value of HSE_VALUE

[regiuliano2009]

Posted on February 24, 2012 at 17:37

thx clive1

I changed PLL_M value but the result is the same üpÀü @25Mhz üpÀü @8Mhz I don't know where else to look I'll send you my source files... I'll hope it's help.I'm using Atollic True Studio lite Thanks in advance ________________ Attachments : src.rar : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I03h&d=%2Fa%2F0X0000000bTS%2F9M3pHzW3WhVxeYiORQ3mhfylrOfc0VakkGoJvC5nmSg&asPdf=false

[Tesla DeLorean]

Posted on February 25, 2012 at 04:54

Well nothing looks to be hideously amiss, I guess at this point I'd be tempted to have it send a continuous stream of characters, 'U' being a particularly clever one, and measure/confirm the bit timing on a scope.

I might also try RealTerm, and try without parity.

[regiuliano2009]

Posted on February 27, 2012 at 11:23

Dear Clive1,

I have performed the test you have

suggested

. I have tried with and without parity but nothing change... I post u some realTerm images (thanks for RT!!!) (->Can't upload images... I put on Attach) As u can see there is an ERROR bit! So I think that the problem is il my FTDI UM232r CHIP that can't handle the communication because the STM32 seems working good I post also a screenshot of PC10 pin of my oscilloscope I freeze the image of stream of U. It's seems work. The output values are: Vpeak-peak 3V Period 659us Freq 1,51 kHz baud= 8bit/2,5ms=3200 ( possible??) Is a problem that Vinput of 3V and not 3,3V for FTDI chip? Thanks again! ________________ Attachments : UART.rar : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I06L&d=%2Fa%2F0X0000000bTR%2F4z5H.V7ZA3AXpr57yQVcV_eoJyBqQk1ZwbqBiyaMod4&asPdf=false