代码示例:
这里使用LPC1343的IO模拟LIS3LV02DL的spi时序。
//--------------传感器接口定义---------------
#define MOSI_H GPIOSetValue( 3, 2, 1 ) //使用的是接口P3.2
#define MOSI_L GPIOSetValue( 3, 2, 0 )
#define SCLK_H GPIOSetValue( 2, 11, 1 ) //使用的是接口P2.11
#define SCLK_L GPIOSetValue( 2, 11, 0 )
#define SSEL_H GPIOSetValue( 0, 2, 1 ) //使用的是接口P0.2
#define SSEL_L GPIOSetValue( 0, 2, 0 )
#define MISO_VALUE GPIOReadValue(0,8) //使用的是接口P0.8
void delay(int i){
while(i--);
}
char spi_comm(unsigned char outgoing_byte)//模拟LIS3LV02DL时序
{
char incoming_byte, x;
SCLK_H; //Pull SPI clock high
delay(100);
for(x = 0 ; x < 8 ; x++)
{
SCLK_L; //Pull SPI clock low
delay(100);
if(outgoing_byte & 0x80)
MOSI_H; //Pull SPI data out high
else
MOSI_L; //Pull SPI data out low
outgoing_byte = outgoing_byte << 1;
SCLK_H; //Pull SPI clock high
delay(100);
incoming_byte = incoming_byte << 1;
incoming_byte = incoming_byte | MISO_VALUE; //获取加速度传感器的输入数据
}
return(incoming_byte);
}
char read_register(unsigned char register_name)// 读LIS3LV02DL寄存器
{
char in_byte;
register_name |= 0x80; //Set D7 to 1 for read mode
SSEL_L; //Select LIS
in_byte = spi_comm(register_name); //SPI read 6-bit register from LIS
in_byte = spi_comm(0x00);
SSEL_H;
return(in_byte);
}
//Sends a write command to LIS
void write_register(unsigned char register_name, unsigned char register_value)//写LIS3LV02DL寄存器
{
unsigned char in_byte;
register_name &= 0x3f; //Clear D7 to 0 for write mode
SSEL_L; //Select LIS
in_byte = spi_comm(register_name); //SPI read 6-bit register from LIS
in_byte = spi_comm(register_value);
SSEL_H;
}
static void setupHardware(void) {//硬件初始化
/* Config CLKOUT, mostly used for debugging. */
CLKOUT_Setup( CLKOUTCLK_SRC_MAIN_CLK );
LPC_IOCON->IO0_1 &= ~0x07;
LPC_IOCON->IO0_1 |= 0x01; /* CLK OUT */
/* Enable AHB clock to the GPIO domain. */
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<6);
/* Set port for LED to output */
GPIOSetDir( SYS_LED_PORT, SYS_LED_BIT, 1 ); //配置系统LED
GPIOSetDir( LED_PORT, LED_BIT, 1 );
//------------for sensor---------------
GPIOSetDir( 3, 2, 1 ); //mosi //配置LIS3LV02DL接口
GPIOSetDir( 0, 8, 0 ); //miso
GPIOSetDir( 2, 11, 1 ); //sclk
GPIOSetDir( 0, 2, 1 ); //ssel
UARTInit(9600);//初始化串口
sensor_data1 = read_register(0x0f);//读取期间ID,应该反馈3A
UARTSendchar(sensor_data1); //从串口可以看到打印0x3A
write_register(LIS3L_CTRL_REG1,0xD7); //设置采样率,160khz,正常工作模式
write_register(LIS3L_CTRL_REG2,0x44); //读取完高字节后数据更新,确保数据传输正确,
}
void vUserTask1(void *pvParameters) {//闪灯任务
while (1) {
if (sys_led_state == LED_OFF) {
GPIOSetValue( SYS_LED_PORT, SYS_LED_BIT, LED_ON );
sys_led_state = LED_ON;
} else {
GPIOSetValue( SYS_LED_PORT, SYS_LED_BIT, LED_OFF );
sys_led_state = LED_OFF;
}
vTaskDelay(10);
}
}
void vUserTask2(void *pvParameters) {//加速度传感器监测任务
while (1) {
sensor_data1 = read_register(LIS3L_OUTZ_L);
sensor_data1 = read_register(LIS3L_OUTX_H);
UARTSendchar(sensor_data1); //打印X轴的高字节
if(sensor_data1>0x00) //判断是否报警,阈值可以根据实际调节
iState = 1;
vTaskDelay(10) ;
}
}
void vUserTask3(void *pvParameters) {//Beep报警任务
while (1) {
if(iState == 1){
GPIOSetValue( 2, 0, 0 );
iState = 0;
}
else
GPIOSetValue( 2, 0, 1 );
vTaskDelay(10) ;
}
}
int main(void) {
setupHardware(); //初始化硬件系统
//建立3个任务
xTaskCreate( vUserTask1, ( signed portCHAR * ) "Sys_led", USERTASK_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
xTaskCreate( vUserTask2, ( signed portCHAR * ) "Sensor", USERTASK_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
xTaskCreate( vUserTask3, ( signed portCHAR * ) "Beep", USERTASK_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
vTaskStartScheduler(); //开始任务调度
return 1;
}