SPI_I2S_ReceiveData总是返回0xff或0x00
SPI_I2S_ReceiveData总是返回0xff或0x00
提问于 2015-10-12 10:17:31
我想创建固件的stm32f4发现，闪烁灯，当板移动。但是SPI_I2S_ReceiveData总是返回0xff或0x00。我认为问题是在我的SPI初始化，但我不知道它到底在哪里。
这是我的密码。
#include <stm32f4xx.h>
#include <stm32f4xx_rcc.h>
#include <stm32f4xx_gpio.h>
#include <stm32f4xx_spi.h>
#include <stm32f4xx_i2c.h>
void InitLEDs(void);
void InitSPI(void);
void Delay(int iTicks);
void DiodeFlash(void);
unsigned short ReadACCELEROMETER(void);
unsigned char WriteSPI(unsigned char cbData);
int main(void)
{
unsigned short cbPrevRead = 0;
unsigned short cbCurrentRead = 0;
InitLEDs();
InitSPI();
while(1)
{
cbCurrentRead = ReadACCELEROMETER();
if (cbCurrentRead != cbPrevRead)
{
DiodeFlash();
cbPrevRead = cbCurrentRead;
}
}
}
void InitLEDs(void)
{
GPIO_InitTypeDef PortD;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
PortD.GPIO_Mode = GPIO_Mode_OUT;
PortD.GPIO_OType = GPIO_OType_PP;
PortD.GPIO_PuPd = GPIO_PuPd_NOPULL;
PortD.GPIO_Speed = GPIO_Speed_100MHz;
PortD.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
GPIO_Init(GPIOD, &PortD);
}
void InitSPI(void)
{
GPIO_InitTypeDef PortA;
GPIO_InitTypeDef PortE;
SPI_InitTypeDef SPI1Conf;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
PortA.GPIO_Mode = GPIO_Mode_AF;
PortA.GPIO_OType = GPIO_OType_PP;
PortA.GPIO_Speed = GPIO_Speed_50MHz;
PortA.GPIO_PuPd = GPIO_PuPd_NOPULL;
PortA.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
GPIO_Init(GPIOA, &PortA);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);
PortE.GPIO_Mode = GPIO_Mode_OUT;
PortE.GPIO_OType = GPIO_OType_PP;
PortE.GPIO_Speed = GPIO_Speed_50MHz;
PortE.GPIO_PuPd = GPIO_PuPd_NOPULL;
PortE.GPIO_Pin = GPIO_Pin_3;
GPIO_Init(GPIOE, &PortE);
GPIOE->ODR = 0x0008; // Disable CS
SPI1Conf.SPI_DataSize = SPI_DataSize_8b;
SPI1Conf.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_64;
SPI1Conf.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI1Conf.SPI_FirstBit = SPI_FirstBit_MSB; // ACCELEROMETER PROTOCOL
SPI1Conf.SPI_Mode = SPI_Mode_Master;
SPI1Conf.SPI_CPHA = SPI_CPHA_2Edge;
SPI1Conf.SPI_CPOL = SPI_CPOL_High;
SPI1Conf.SPI_CRCPolynomial = 7;
SPI1Conf.SPI_NSS = SPI_NSS_Soft;
SPI_Init(SPI1, &SPI1Conf);
SPI_Cmd(SPI1, ENABLE);
WriteSPI(0x23); WriteSPI(0xc9);
WriteSPI(0x20); WriteSPI(0x97);
WriteSPI(0x24); WriteSPI(0x00);
WriteSPI(0x10); WriteSPI(0x00);
WriteSPI(0x11); WriteSPI(0x00);
WriteSPI(0x12); WriteSPI(0x00);
}
void Delay(int iTicks)
{
while ((iTicks--) > 0);
}
void DiodeFlash(void)
{
GPIO_Write(GPIOD, 1UL << 12);
Delay(100000);
GPIO_Write(GPIOD, 1UL << 13);
Delay(100000);
GPIO_Write(GPIOD, 1UL << 14);
Delay(100000);
GPIO_Write(GPIOD, 1UL << 15);
Delay(100000);
GPIO_Write(GPIOD, 0x0000);
}
unsigned short ReadACCELEROMETER(void)
{
unsigned short nAxisX = 0x0000;
unsigned short nAxisY = 0x0000;
unsigned short nAxisZ = 0x0000;
unsigned char cbAddress = 0x80;
//**********************************************************
// Forming X Value
WriteSPI(cbAddress | 0x0f);
nAxisX |= WriteSPI(0x00);
WriteSPI(cbAddress | 0x2A);
nAxisX |= WriteSPI(0x00) << 8;
//**********************************************************
// Forming Y Value
WriteSPI(cbAddress | 0x2B);
nAxisX |= WriteSPI(0x00);
WriteSPI(cbAddress | 0x2C);
nAxisX |= WriteSPI(0x00) << 8;
//**********************************************************
// Forming Z Value
WriteSPI(cbAddress | 0x2D);
nAxisX |= WriteSPI(0x00);
WriteSPI(cbAddress | 0x2E);
nAxisX |= WriteSPI(0x00) << 8;
return nAxisX ^ nAxisY ^ nAxisZ;
}
unsigned char WriteSPI(unsigned char cbData)
{
unsigned char cbResult = 0x00;
GPIOE->ODR = 0x0000; // Enable CS
// Wait for ready status
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
SPI_I2S_SendData(SPI1, cbData);
// Wait for ready status
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
cbResult = SPI_I2S_ReceiveData(SPI1);
GPIOE->ODR = 0x0008; // Disable CS
return cbResult;
}回答 3
Stack Overflow用户
回答已采纳
发布于 2015-10-12 13:25:01
首先，你没有指定你的加速度计。我可以猜到，那是圣LISxx。
在这种情况下，有错误的数据传输到加速度计。
正确的写入顺序：
- 激活芯片组
- 写寄存器号
- 写寄存器值
- 失活芯片组 使用类似的顺序读取每个寄存器。
接下来，ST不建议您的algo用于低级别SPI转移：
不要使用BSY标志来处理每个数据传输或接收。最好使用TXE和RXNE标志。
(见参考手册)。简单地使用
SPIx->DR = out;
while (!(SPIx->SR & SPI_SR_RXNE)) ;
return SPIx->DR; 另外，我正在使用LIS3DH和CPOL=0 & CPHA =0 SPI设置(我不知道它将如何与您的CPOL=1，CPHA=1一起工作)。
提示:要检查SPI通信，请尝试读取WHO_AM_I寄存器--它已启用并始终具有已知值。
Stack Overflow用户
发布于 2015-11-04 18:03:22
这是因为你写的地址的寄存器，在取消选择你的设备，所以写的地址是清理。在这种情况下，你必须这样做。
unsigned char WriteSPI(unsigned char cbData)
{
unsigned char cbResult = 0x00;
// Wait for ready status
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
SPI_I2S_SendData(SPI1, cbData);
// Wait for ready status
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
cbResult = SPI_I2S_ReceiveData(SPI1);
return cbResult;
}
unsigned char WriteReg(unsigned char cbAddress, unsigned char cbData)
{
unsigned char cbResult = 0x00;
GPIOE->ODR = 0x0000; // select device
WriteSPI(cbAddress);
cbResult = WriteSPI(cbData);
GPIOE->ODR = 0x0008; // deselect device
return cbResult;
}
unsigned char ReadReg(unsigned char cbAddress)
{
unsigned char cbResult = 0x00;
GPIOE->ODR = 0x0000; // select device
WriteSPI(cbAddress);
cbResult = WriteSPI(0x00);
GPIOE->ODR = 0x0008; // deselect device
return cbResult;
}Stack Overflow用户
发布于 2015-11-11 08:59:55
SPI初始化没有任何问题。主要的错误是写上注册地址。在读取寄存器值之前，不能取消选择设备，而是必须在一个批处理中执行写地址读取值。这意味着
- 选择设备。
- 写注册地址。
- 读取寄存器值。
- 取消选择装置。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/33078660
复制相关文章
相似问题
腾讯云开发者
Copyright © 2013 - 2026 Tencent Cloud. All Rights Reserved. 腾讯云 版权所有
深圳市腾讯计算机系统有限公司 ICP备案/许可证号：粤B2-20090059 
粤公网安备44030502008569号
腾讯云计算（北京）有限责任公司 京ICP证150476号 | 京ICP备11018762号