Question
No Output Voltage from TI DAC chip，with stm32F7
Hi,there.I am using DAC60508 with my STM32F7，60508 is 12 bits precision，and with 24 bits command-length，SPI interface. After initialize the SPI，I send 3 bytes separately，and I use a oscilloscope to check the wave of SCL�?SDI�?CS，its seems right，but i cant detect any output votage. This SPI2 code demonstrated working with another thermal chip.
static void MX_SPI2_Init(void)
{
LL_SPI_InitTypeDef SPI_InitStruct;
LL_GPIO_InitTypeDef GPIO_InitStruct;
/* Peripheral clock enable */
LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_SPI2);
/**SPI2 GPIO Configuration
PC2 ------> SPI2_MISO
PC3 ------> SPI2_MOSI
PB10 ------> SPI2_SCK
*/
GPIO_InitStruct.Pin = LL_GPIO_PIN_2;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
GPIO_InitStruct.Alternate = LL_GPIO_AF_5;
LL_GPIO_Init(GPIOC, &GPIO_InitStruct);
GPIO_InitStruct.Pin = LL_GPIO_PIN_3;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
GPIO_InitStruct.Alternate = LL_GPIO_AF_5;
LL_GPIO_Init(GPIOC, &GPIO_InitStruct);
GPIO_InitStruct.Pin = LL_GPIO_PIN_10;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
GPIO_InitStruct.Alternate = LL_GPIO_AF_5;
LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* SPI2 parameter configuration*/
SPI_InitStruct.TransferDirection = LL_SPI_FULL_DUPLEX;
SPI_InitStruct.Mode = LL_SPI_MODE_MASTER;
SPI_InitStruct.DataWidth = LL_SPI_DATAWIDTH_8BIT;
SPI_InitStruct.ClockPolarity = LL_SPI_POLARITY_LOW;
SPI_InitStruct.ClockPhase = LL_SPI_PHASE_2EDGE;
SPI_InitStruct.NSS = LL_SPI_NSS_SOFT;
SPI_InitStruct.BaudRate = LL_SPI_BAUDRATEPRESCALER_DIV256;
SPI_InitStruct.BitOrder = LL_SPI_MSB_FIRST;
SPI_InitStruct.CRCCalculation = LL_SPI_CRCCALCULATION_DISABLE;
SPI_InitStruct.CRCPoly = 7;
LL_SPI_Init(SPI2, &SPI_InitStruct);
// LL_SPI_SetStandard(SPI2, LL_SPI_PROTOCOL_MOTOROLA);
// LL_SPI_EnableNSSPulseMgt(SPI2);
}
LL_SPI_SetRxFIFOThreshold(SPI2, LL_SPI_RX_FIFO_TH_QUARTER );
while(1)
{
LL_GPIO_ResetOutputPin(SPI2_NSS_GPIO_Port,SPI2_NSS_Pin); //CS
SPI_SendByte(0x08); //Output 0 Address
SPI_SendByte(0xff); //Data MSB 8 bits
SPI_SendByte(0xf0); //Data LSB 4 bits
delay_us(120);
LL_GPIO_SetOutputPin(SPI2_NSS_GPIO_Port,SPI2_NSS_Pin); // CS
delay_ms(50);
}
unsigned char SPI_SendByte(unsigned char byte)
{
while(LL_SPI_IsActiveFlag_TXE(SPI2)==RESET);
LL_SPI_TransmitData8(SPI2,byte);
// while(! (LL_SPI_IsActiveFlag_RXNE(SPI2)));
// return LL_SPI_ReceiveData8(SPI2);
}
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