STM32F4: no clock on SPI

[matthiaspfister9]

Posted on June 12, 2012 at 13:41The original post was too long to process during our migration. Please click on the attachment to read the original post.

[frankmeyer9]

Posted on June 12, 2012 at 14:01 Stupid question: Do you call your initialization function init_SPI_Config() anywhere ? I did not see any call...

[matthiaspfister9]

Posted on June 12, 2012 at 14:06

Yes, I do. I forgot to copy this part of the code:

void Init_Init(void) {   init_RCC_Config();   init_GPIO_Config();   init_TIM_Config();   init_SYSTICK_Config();     init_DCMI_Config();   init_SPI_Config(); }

[Tesla DeLorean]

Posted on June 12, 2012 at 15:40

I'm pretty sure you're going to need to send some sacrificial data to generate receive clocks, and make sure you clear RXNE before doing so.

SPI_I2S_ReceiveData() just reads a holding register, it does not generate clocks.

[John F.]

Posted on June 12, 2012 at 15:52

Correct! Also see the SPI Flash example in the STM32F4 Library Examples to see how they do it.

[emalund]

Posted on June 12, 2012 at 17:39

 I'm pretty sure you're going to need to send some sacrificial data to generate receive clocks,

I'm absolutely positive you're going to need to send some data to generate receive clocks. SPI does not have receive clocks only ''clocks generated by transmit''. for some protocols, the transmit data is not ''sacrificial'' Erik

[joerg23]

Posted on March 15, 2013 at 22:06

SCLK must be B10 and not B13

[Tesla DeLorean]

Posted on March 15, 2013 at 22:27

SCLK must be B10 and not B13

Under what circumstances? Care to elaborate?

[GUIRAT.Youssef]

Posted on April 25, 2014 at 12:26

Hi everyone , 

i'm working on a wave player project using the SPI communication options.So , I configure the SPI as given below:RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); /* SPI1 configuration */ 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_Low; SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge; SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; // 72000kHz/256=281kHz < 400kHz SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; SPI_InitStructure.SPI_CRCPolynomial = 7;        SPI_Init(SPI2, &SPI_InitStructure); SPI_NSSInternalSoftwareConfig(SPI2, SPI_NSSInternalSoft_Set); SPI_CalculateCRC(SPI2, DISABLE); SPI_Cmd(SPI2, ENABLE);The pins connections are used in AF mode with gpioB But , when i wanna see the sck clock edge , i just have a constant signal value of 3v (position high) I am sure that i have missed something with the the configuration but i didn't know what exactly Can someone help me please :\ ??

[glory_man]

Posted on April 25, 2014 at 14:21

1. Generally data transmittion via spi starts when master device drives CS(NSS) pin low.

2. The transmit sequence begins when a byte is written in the Tx Buffer. Did you put any data in to SPI_DR register?