[solved]Problem: SPI1 doesn't work (no activity on SCK, MOSI)

[jbolting9]

Posted on January 17, 2010 at 19:54

[solved]Problem: SPI1 doesn't work (no activity on SCK, MOSI)

[jbolting9]

Posted on May 17, 2011 at 13:38

Hello everyone,

in order to communicate with a EADOGM128-64 LCD-display, I set up the SPI1 interface of my STM32. Nevertheless there is no clock signal on the SCK pin and no data signal on the MOSI pin while I am sending bytes. Any idea where I'm going wrong? MOSI and SCK are configured as alternate function push-pull. controller: STM32F103-RBT6 on STM32-H103 board by olimex toolchain: codesourcery arm-2009q1-161-arm-none-eabi initialization routine:void SPI1_Init() { SPI1_ClkInit(); //enable SPI1 clock SPI1_I2SCFGR = 0; //set to default; enable SPI mode SPI1_CR1 = 0; //set to default SPI1_CR1 |= (BIT5 | BIT3); //set baudrate to fpclk/64 SPI1_CR1 |= BIT0; //data capture on second SCLK transition SPI1_CR1 |= BIT2; //Master mode SPI1_CR1 |= BIT1; //SPI1_SCLK = high when idle SPI1_CR1 |= BIT9; //enable NSS software mode SPI1_CR1 |= BIT6; //enable SPI1 return; } enable SPI1 clock:void SPI1_ClkInit(void) { RCC_APB2ENR |= BIT12; //enable SPI1 clock return; } function to send data:void SPI1_SendByte(u8 databyte) { SPI1_DR = (u16)databyte; return; } best regards, jan [ This message was edited by: j.bolting on 18-01-2010 00:22 ]

[16-32micros]

Posted on May 17, 2011 at 13:38

Dear Jan,

You forgot to enable the I/Os mapped to SCK, MOSI as ''alternate function'' Push-pull . Once enabled you will see your frame out. Cheers, STOne-32. [ This message was edited by: STOne-32 on 14-01-2010 21:16 ]

[jbolting9]

Posted on May 17, 2011 at 13:38

Hi,

the GPIO clocks are enabled by an initialization routine not documented in my posting; both ports (GPIO_A and GPIO_C) are successfully used for USART transmissions. regards, Jan [ This message was edited by: j.bolting on 15-01-2010 19:57 ] [ This message was edited by: j.bolting on 15-01-2010 19:58 ]

[jbolting9]

Posted on May 17, 2011 at 13:38

Hello,

I had to set the SSI bit in the SPI1_CR1 Register. Now it works as expected. But I'm still working on why that was the reason. cheers, jan [ This message was edited by: j.bolting on 18-01-2010 00:35 ]