【疯狂的四驱车】实验四 8700驱显

zhjb1

今天有空，昨天看到有人在做板载传感器的作文，于是也来额外实验，与小车可能无关。
8700传感器有3轴输出，为+-V。此模块的应用在SDK2.0.0中的I2C中的read_accel_value_transfer里面。
方法与以前的基本一样，也是主要更改：
board.h中的IO口设置，挡使用TIP、LPTMR 5、UART、ADC后发现以前是用的IO口冲突，为了省事——实际上是为了躲避模块设置的函数不理解，刺猬案例程使用此I/O口有他的道理，所以仅仅更改LCD的口，改到C16,17；B18，19，那么这些模块的I/O口就自己使用了。
board.h只有以下是自己设的：
//4Line LCD I/O Define
#define res  GPIOB
#define resPin 18U
#define reg  GPIOB
#define regPin 19U
#define clk  GPIOC
#define clkPin 16U
#define sda  GPIOC
#define sdaPin 17U
其他的只是拷贝过来

改pin_mux.c
//Declare and initialise for pull up configuration
port_pin_config_t pinConfig = {0};
pinConfig.pullSelect = kPORT_PullUp;
#if defined(FSL_FEATURE_PORT_HAS_OPEN_DRAIN) && FSL_FEATURE_PORT_HAS_OPEN_DRAIN
pinConfig.openDrainEnable = kPORT_OpenDrainEnable;
#endif //FSL_FEATURE_PORT_HAS_OPEN_DRAIN

//Initialize UART1 pins below //Ungate the port clock
CLOCK_EnableClock(kCLOCK_PortB);
//Affects PORTB_PCR16 PORTB_PCR17 register
PORT_SetPinMux(PORTB,16U,kPORT_MuxAlt3);
PORT_SetPinMux(PORTB,17U,kPORT_MuxAlt3);
//Ungate the port clock
CLOCK_EnableClock(kCLOCK_PortE);
//I2C0 pull up resistor setting
PORT_SetPinConfig(PORTE,24U,&pinConfig);
PORT_SetPinConfig(PORTE,25U,&pinConfig);
//I2C0 PIN_MUX Configuration
PORT_SetPinMux(PORTE,24U,kPORT_MuxAlt5);
PORT_SetPinMux(PORTE,25U,kPORT_MuxAlt5);
//Ungate the port clock
CLOCK_EnableClock(kCLOCK_PortC);
//I2C1 pull up resistor setting
PORT_SetPinConfig(PORTC,10U,&pinConfig);
PORT_SetPinConfig(PORTC,11U,&pinConfig);
//I2C1 PIN_MUX Configuration
PORT_SetPinMux(PORTC,10U,kPORT_MuxAlt2);
PORT_SetPinMux(PORTC,11U,kPORT_MuxAlt2);

//PTB2, ADC0_SE12 PTB3,ADC0_SE13
PORT_SetPinMux(PORTB,2U,kPORT_PinDisabledOrAnalog);
PORT_SetPinMux(PORTB,3U,kPORT_PinDisabledOrAnalog);

并且将函数void BOARD_I2C_ReleaseBus(void)。拷贝的此文档中
主函数中添加头文件#include "fsl_i2c.h"
添加定义变量等：
//Definitions
#define ACCEL_I2C_CLK_SRC I2C0_CLK_SRC
#define I2C_BAUDRATE 100000U
#define FOXS8700_WHOAMI 0xC7U
#define MMA8451_WHOAMI 0x1AU
#define ACCEL_STATUS 0x00U
#define ACCEL_XYZ_DATA_CFG 0x0EU
#define ACCEL_CTRL_REG1 0x2AU
//FOXS8700 and MMA8451 have the same who_am_i register address.
#define ACCEL_WHOAMI_REG 0x0DU
#define ACCEL_READ_TIMES 10U


static bool I2C_ReadAccelWhoAmI(void);
static bool I2C_WriteAccelReg(I2C_Type *base, uint8_t device_addr, uint8_t reg_addr, uint8_t value);
static bool I2C_ReadAccelRegs(I2C_Type *base, uint8_t device_addr, uint8_t reg_addr, uint8_t *rxBuff, uint32_t rxSize);

//Variables  FOXS8700 and MMA8451 device address
const uint8_t g_accel_address[] = {0x1CU, 0x1DU, 0x1EU, 0x1FU};
i2c_master_handle_t g_m_handle;
volatile bool pitIsrFlag = false;


添加各种变量定义：
int16_t xx,yy,zz;
uint8_t g_accel_addr_found = 0x00,status0_value=0;
volatile bool completionFlag = false;
volatile bool nakFlag = false;
bool isThereAccel = false;

将原来main中的读取I2C——8700 数据的语句移出定义函数：
//I2C Read Datas onse
void i2cRead(void){
if (true == isThereAccel) {
  uint8_t databyte = 0;
  uint8_t write_reg = 0;
  uint8_t readBuff[7];
  //int16_t x, y, z;
  //uint8_t status0_value = 0;
  uint32_t i = 0U;
  /*  please refer to the "example FXOS8700CQ Driver Code" in FXOS8700 datasheet. */
  /*  write 0000 0000 = 0x00 to accelerometer control register 1 */
  /*  standby */
  /*  [7-1] = 0000 000 */
  /*  [0]: active=0 */
  write_reg = ACCEL_CTRL_REG1;
  databyte = 0;
  I2C_WriteAccelReg(BOARD_ACCEL_I2C_BASEADDR, g_accel_addr_found, write_reg, databyte);
  /*  write 0000 0001= 0x01 to XYZ_DATA_CFG register */
  /*  [7]: reserved */
  /*  [6]: reserved */
  /*  [5]: reserved */
  /*  [4]: hpf_out=0 */
  /*  [3]: reserved */
  /*  [2]: reserved */
  /*  [1-0]: fs=01 for accelerometer range of +/-4g range with 0.488mg/LSB */
  /*  databyte = 0x01; */
  write_reg = ACCEL_XYZ_DATA_CFG;
  databyte = 0x01;
  I2C_WriteAccelReg(BOARD_ACCEL_I2C_BASEADDR, g_accel_addr_found, write_reg, databyte);
  /*  write 0000 1101 = 0x0D to accelerometer control register 1 */
  /*  [7-6]: aslp_rate=00 */
  /*  [5-3]: dr=001 for 200Hz data rate (when in hybrid mode) */
  /*  [2]: lnoise=1 for low noise mode */
  /*  [1]: f_read=0 for normal 16 bit reads */
  /*  [0]: active=1 to take the part out of standby and enable sampling */
  /*   databyte = 0x0D; */
  write_reg = ACCEL_CTRL_REG1;
  databyte = 0x0d;
  I2C_WriteAccelReg(BOARD_ACCEL_I2C_BASEADDR, g_accel_addr_found, write_reg, databyte);
  PRINTF("The accel values:\r\n");
  for (i = 0; i < ACCEL_READ_TIMES; i++){//默认读取8次数据，可以按照要求直接将ACCEL_READ_TIMES改成具体id额数值，比如1——读数据次
   status0_value = 0;
   /*  wait for new data are ready. */
   while (status0_value != 0xff){
    I2C_ReadAccelRegs(BOARD_ACCEL_I2C_BASEADDR, g_accel_addr_found, ACCEL_STATUS, &status0_value, 1);
   }
   /*  Multiple-byte Read from STATUS (0x00) register */
   I2C_ReadAccelRegs(BOARD_ACCEL_I2C_BASEADDR, g_accel_addr_found, ACCEL_STATUS, readBuff, 7);
   status0_value = readBuff[0];
   xx = ((int16_t)(((readBuff[1] * 256U) | readBuff[2]))) / 8U;
   yy = ((int16_t)(((readBuff[3] * 256U) | readBuff[4]))) / 8U;
   zz = ((int16_t)(((readBuff[5] * 256U) | readBuff[6]))) / 8U;
   PRINTF("status_reg = 0x%x , x = %5d , y = %5d , z = %5d \r\n", status0_value, xx, yy, zz);
  }
}
}

至此我将tip中断的计数js作为读数据周期，设定为1S1次，结果看照片。为了数据一致性，PC的屏幕与LCD的数据都拍下来，只是清晰度差点。实际数值是除以8，这样最大数值大约为1028左右。
查看了ftm模块，里面应该有PWM的函数，研究一下应该能解决，就剩下I/O计数得到小车速度的参数了。下周应该有小结果了。

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