We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi, Please help me to know why the following example code for SPI of STM32L152VD is not working, I do not see any signals in scope on pins SCK and MOSI niether in Data register in dubugger.
void SPI_Master_init(void) { GPIO_InitTypeDef GPIO_InitStruct; SPI_InitTypeDef SPI_InitStruct; /* Initialization and Configuration functions *********************************/ // enable peripheral clock RCC_AHBPeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE); RCC_AHBPeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE); GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_40MHz; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_Init(GPIOA, &GPIO_InitStruct); GPIO_InitStruct.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_40MHz; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_Init(GPIOB, &GPIO_InitStruct); // connect SPI1 pins to SPI alternate function GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1); GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1); GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1); // // connect SPI2 pins to SPI alternate function GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_SPI2); GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_SPI2); GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_SPI2); SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex; // set to full duplex SPI_InitStruct.SPI_Mode = SPI_Mode_Master; // transmit in master mode, NSS pin has SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b; // one packet of data is 8 bits wide SPI_InitStruct.SPI_CPOL = SPI_CPOL_Low; // clock is low when idle SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge; // data sampled at first edge SPI_InitStruct.SPI_NSS = SPI_NSS_Hard; // set the NSS HARD SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; // SPI frequency is SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;// data is transmitted MSB first SPI_Init(SPI1, &SPI_InitStruct); SPI_SSOutputCmd(SPI1,ENABLE); //Set SSOE bit in SPI_CR1 register SPI_Cmd(SPI1, ENABLE); // enable SPI1 SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex; // set to full duplex SPI_InitStruct.SPI_Mode = SPI_Mode_Master; // transmit in master mode, NSS pin has SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b; // one packet of data is 8 bits wide SPI_InitStruct.SPI_CPOL = SPI_CPOL_Low; // clock is low when idle SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge; // data sampled at first edge SPI_InitStruct.SPI_NSS = SPI_NSS_Hard; // set the NSS HARD SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; // SPI frequency is SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;// data is transmitted MSB first SPI_Init(SPI2, &SPI_InitStruct); SPI_SSOutputCmd(SPI2,ENABLE); //Set SSOE bit in SPI_CR1 register SPI_Cmd(SPI2, ENABLE); // enable SPI2
and in main:
int main(void){ SPI_Master_init(); while(1) { SPI_I2S_SendData(SPI1, 0xFFFF); SPI1->DR = 0x11; SPI_I2S_SendData(SPI2,0xFFFF); SPI2->DR = 0x11;
http://www.keil.com/forum/59935/
I have made a header board for STM32L152VD after every restart it takes few seconds for the board to start running. I used the same program to run on STM32L152RC discovery board but I had no problem.
-->
Did the mentioned SPI problem happen on the header board for STM32L152VD or the STM32L152RC discovery board?
Dear John, I tested the program in both boards.The one I made with STM32L152VD and STM32L discovery both have same problem. I check the SCK and MISO by scope while not connected to slave. Is it necessary to connect to slave in SPI while checking by scope?
No much use looking at the MISO signal without a slave. This signal is Master In, Slave Out. So driven by the slave.
It's the MOSI you want to look at - Master Out, Slave In. But then you don't want to send 0xFFFF since that doesn't give you any nice action on the pin.
The clock signal is always owned by the master and should always play when the master tries to send - no need for any slave connected.
Dear Per, You are right. It was a mistake in typing. I am expecting to see signals on SCK and MOSI.