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STM32F4 Discovery + FreeRTOS + TouchScreen

zavodny
Associate II
Posted on February 17, 2014 at 23:39

Hello,

can you help me with touching controller and STM32F4 Discovery kit? I use controller XPT2046 with SPI and I want use SPI2. I know, that SPI 2 is on pins PC2, PC3 and PB Is it true? I init this pins in touch_init function and the function not working still. I'm using with FreeRTOS. Is it problem?

Here is my code for init:

void
touch_init(
void
) 
{ 
SPI_InitTypeDef SPI_InitStructure; 
GPIO_InitTypeDef GPIO_InitStruct; 
NVIC_InitTypeDef NVIC_InitStructure; 
EXTI_InitTypeDef EXTI_InitStructure; 
RCC_AHB1PeriphClockCmd( RCC_AHB1Periph_GPIOC|RCC_AHB1Periph_GPIOB|RCC_AHB1Periph_GPIOD, ENABLE); 
GPIO_InitStruct.GPIO_Mode=GPIO_Mode_AF; 
GPIO_InitStruct.GPIO_Speed=GPIO_Speed_25MHz; 
GPIO_InitStruct.GPIO_OType=GPIO_OType_PP; 
GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_UP; 
GPIO_InitStruct.GPIO_Pin=GPIO_Pin_10; 
GPIO_Init(GPIOB,&GPIO_InitStruct); 
GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_SPI2); 
//SCLK 
GPIO_InitStruct.GPIO_Mode=GPIO_Mode_AF; 
GPIO_InitStruct.GPIO_Speed=GPIO_Speed_25MHz; 
GPIO_InitStruct.GPIO_OType=GPIO_OType_PP; 
GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_UP; 
GPIO_InitStruct.GPIO_Pin=GPIO_Pin_2|GPIO_Pin_3; 
GPIO_Init(GPIOC,&GPIO_InitStruct); 
GPIO_PinAFConfig(GPIOC, GPIO_PinSource2, GPIO_AF_SPI2); 
//MISO 
GPIO_PinAFConfig(GPIOC, GPIO_PinSource3, GPIO_AF_SPI2); 
//MOSI 
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); 
SPI_I2S_DeInit(SPI2); 
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; 
SPI_InitStructure.SPI_Mode = SPI_Mode_Master; 
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; 
SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
//SPI_CPOL_Low SPI_CPOL_High 
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge; 
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; 
//SPI_NSS_Hard //SPI_NSS_Soft 
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; 
//16 
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; 
SPI_InitStructure.SPI_CRCPolynomial = 7; 
SPI_Init(SPI2,&SPI_InitStructure); 
SPI_Cmd(SPI2,ENABLE); 
//CS 
GPIO_InitStruct.GPIO_Mode=GPIO_Mode_OUT; 
GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz; 
GPIO_InitStruct.GPIO_OType=GPIO_OType_PP; 
GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_UP; 
GPIO_InitStruct.GPIO_Pin=GPIO_Pin_14; 
// 3 
GPIO_Init(GPIOB,&GPIO_InitStruct); 
// d 
T_DCS(); 
//T_PEN 
GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IN; 
GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz; 
GPIO_InitStruct.GPIO_OType=GPIO_OType_PP; 
GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_UP; 
GPIO_InitStruct.GPIO_Pin=GPIO_Pin_6; 
GPIO_Init(GPIOD,&GPIO_InitStruct); 
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); 
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOD, EXTI_PinSource6); 
EXTI_InitStructure.EXTI_Line = EXTI_Line6; 
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; 
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; 
EXTI_InitStructure.EXTI_LineCmd = ENABLE; 
EXTI_Init(&EXTI_InitStructure); 
NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn; 
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F; 
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F; 
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 
NVIC_Init(&NVIC_InitStructure); 
}

And then I write and read data by this function:

unsigned 
char
SPI_WriteByte(u8 num) 
{ 
unsigned 
char
Data = 0;
while
(SPI_I2S_GetFlagStatus(SPI2,SPI_I2S_FLAG_TXE)==RESET); 
SPI_I2S_SendData(SPI2,num); 
while
(SPI_I2S_GetFlagStatus(SPI2,SPI_I2S_FLAG_RXNE)==RESET); 
Data = SPI_I2S_ReceiveData(SPI2);
return
Data; 
} 

Can you help me please? #xpt2046 #spi #stm32f4
11 REPLIES 11
chen
Associate II
Posted on February 19, 2014 at 10:36

''Now I try init SPI after all functions. Now CLK is OK. But MOSI is not send to uC.''

Are you sure the data is not just 0x00 ?

zavodny
Associate II
Posted on February 19, 2014 at 15:09

Problem SOLVED. Thank you! 

Mistake is in pins. Other function use the same pins.