我正在使用带有MAX30102传感器的 texas msp432p401r 板。两者之间的连接是通过i2c。我不明白为什么在传感器初始化时我不能写入寄存器。执行挂在第一个 init_MAX () 语句上。与卡的连接都正确，寄存器地址也正确。我试图检查手册，但我不明白为什么它不起作用。
//__________________________
//Hardware Cnonfiguration |
|
//MSP432 MAX30102 |
//P1.7 ---> SCL |
//P1.6 ---> SDA |
//p1.5 ---> INT |
//3.3V ---> VIN |
//GND ---> GND |
//__________________________|
/* DriverLib Defines */
#include <ti/devices/msp432p4xx/driverlib/driverlib.h>
/* Standard Defines */
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <stdio.h>
/* Slave Address for I2C Slave */
#define MAX_ADDRESS 0x57
//Register Addresses
#define REG_INTR_STATUS_1 0x00
#define REG_INTR_STATUS_2 0x01
#define REG_INTR_ENABLE_1 0x02
#define REG_INTR_ENABLE_2 0x03
#define REG_FIFO_WR_PTR 0x04
#define REG_OVF_COUNTER 0x05
#define REG_FIFO_RD_PTR 0x06
#define REG_FIFO_DATA 0x07
#define REG_FIFO_CONFIG 0x08
#define REG_MODE_CONFIG 0x09
#define REG_SPO2_CONFIG 0x0A
#define REG_LED1_PA 0x0C
#define REG_LED2_PA 0x0D
#define REG_PILOT_PA 0x10
#define REG_MULTI_LED_CTRL1 0x11
#define REG_MULTI_LED_CTRL2 0x12
#define REG_TEMP_INTR 0x1F
#define REG_TEMP_FRAC 0x20
#define REG_TEMP_CONFIG 0x21
#define REG_PROX_INT_THRESH 0x30
#define REG_REV_ID 0xFE
#define REG_PART_ID 0xFF
//function prototypes
void init_I2C();
void Reg_Write (uint8_t reg_address, uint8_t data);
void Reg_Read(uint8_t Reg_address);
void init_MAX();
void fifo_read();
void putsUART(char *s);
void config_interrupt();
//Other Constants
#define FIFO_DEPTH 96
/*Global Variables*/
uint32_t fifo_data_r[FIFO_DEPTH];//fifoData for red led buffer[number_of_samples]
uint32_t fifo_data_ir[FIFO_DEPTH];//fifoData for infra red led buffer[number_of_samples]
uint8_t reg_data;
char str[80];
uint8_t fifo_read_count = 0;
uint8_t reg_num; //1 to read one byte of data and 3 to read 3 bytes of data
uint8_t ready = 0;
/* I2C Master Configuration Parameter */
const eUSCI_I2C_MasterConfig i2cConfig =
{
EUSCI_B_I2C_CLOCKSOURCE_SMCLK, // SMCLK Clock Source
12000000, // SMCLK = 3MHz or 12MHz
EUSCI_B_I2C_SET_DATA_RATE_400KBPS, // Desired I2C Clock of 400khz or 100khz
0, // No byte counter threshold
EUSCI_B_I2C_NO_AUTO_STOP // No Autostop
};
/*UART COnfiguration Parameter for 9600 baud rate*/
const eUSCI_UART_ConfigV1 uartConfig =
{
EUSCI_A_UART_CLOCKSOURCE_SMCLK, // SMCLK Clock Source
78, // BRDIV = 78
2, // UCxBRF = 2
0, // UCxBRS = 0
EUSCI_A_UART_NO_PARITY, // No Parity
EUSCI_A_UART_LSB_FIRST, // LSB First
EUSCI_A_UART_ONE_STOP_BIT, // One stop bit
EUSCI_A_UART_MODE, // UART mode
EUSCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION, // Oversampling
EUSCI_A_UART_8_BIT_LEN // 8 bit data length
};
/*********************************************************************************************************/
/*Init I2C
* This function initializes i2c on the msp432 based on the setting in the 12cConfig structure */
/*********************************************************************************************************/
void init_I2C(void)
{
/* Select Port 1 for I2C - Set Pin 6, 7 to input Primary Module Function,
* (UCB0SIMO/UCB0SDA, UCB0SOMI/UCB0SCL).
*/
MAP_GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P1,
GPIO_PIN6 + GPIO_PIN7, GPIO_PRIMARY_MODULE_FUNCTION);
/* Initializing I2C Master to SMCLK at 400khz with no autostop */
MAP_I2C_initMaster(EUSCI_B0_BASE, &i2cConfig);
/* Specify slave address */
MAP_I2C_setSlaveAddress(EUSCI_B0_BASE, MAX_ADDRESS);
/* Enable I2C Module to start operations */
MAP_I2C_enableModule(EUSCI_B0_BASE);
MAP_Interrupt_enableInterrupt(INT_EUSCIB0);
}
/*********************************************************************************************************/
/*config_interrupt This function configures the interrupt pin on the MSP432 */
/*********************************************************************************************************/
void config_interrupt()
{
// Configuring P1.0 as output and P1.1 (switch) as input
MAP_GPIO_setAsOutputPin(GPIO_PORT_P1, GPIO_PIN0);
// Configuring P5.7 as an input and enabling interrupts
MAP_GPIO_setAsInputPinWithPullUpResistor(GPIO_PORT_P5, GPIO_PIN7);
MAP_GPIO_clearInterruptFlag(GPIO_PORT_P5, GPIO_PIN7);
MAP_GPIO_interruptEdgeSelect(GPIO_PORT_P5,GPIO_PIN7,GPIO_HIGH_TO_LOW_TRANSITION);
MAP_GPIO_enableInterrupt(GPIO_PORT_P5, GPIO_PIN7);
MAP_Interrupt_enableInterrupt(INT_PORT5);
// Enabling MASTER interrupts
MAP_Interrupt_enableMaster();
MAP_GPIO_setOutputHighOnPin(GPIO_PORT_P1, GPIO_PIN0);
}
/*********************************************************************************************************/
/*interrupt service routine This function services the interrupt pin on the MSP432 */
/*********************************************************************************************************/
void PORT5_IRQHandler(void)
{
uint32_t status;
// uint8_t i;
status = MAP_GPIO_getEnabledInterruptStatus(GPIO_PORT_P5);
MAP_GPIO_clearInterruptFlag(GPIO_PORT_P5, status);
// Toggling the output on the LED and calling the fifo_read function if the interrupt is reached
if(status & GPIO_PIN7)
{
MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P1, GPIO_PIN0);
fifo_read();
}
}
/*********************************************************************************************************/
/* init_MAX This function is used to initialize the MAX30102 */
/*********************************************************************************************************/
void init_MAX()
{
Reg_Write(REG_MODE_CONFIG,0x40); //Reset Device
Reg_Read( REG_INTR_STATUS_1); //clear interrupt status
Reg_Read( REG_INTR_STATUS_2);
Reg_Write(REG_INTR_ENABLE_1,0xC0);//enable FIFO almost full and PPG ready
Reg_Write(REG_INTR_ENABLE_2,0x00);
Reg_Write(REG_FIFO_WR_PTR,0x00); //reset fifo write pointer
Reg_Write(REG_OVF_COUNTER,0x00); //reset fifo overflow counter
Reg_Write(REG_FIFO_RD_PTR,0x00); //reset fifo read pointer
Reg_Write(REG_FIFO_CONFIG,0x40); //sample avg = 4, no fifo rollover, fifo almost full = 0
Reg_Write(REG_SPO2_CONFIG,0x47); //LSB = 31.25pA, sample rate = 100Hz, Pulse width 411us//was 0x27
Reg_Write(REG_LED1_PA,0x5A); //LED current 7.8mA 0x24 or 0x27
Reg_Write(REG_LED2_PA,0x5A); //LED current 7.2mA //not important for heart rate mode
Reg_Write(REG_PILOT_PA,0x19);
Reg_Write(REG_PROX_INT_THRESH,0x21);
Reg_Write(REG_MODE_CONFIG,0x02); //heart rate mode //0x02 hr 0x03 spo2
}
/*********************************************************************************************************/
/* Reg_Write This function is used to write to the registers in the MAX30102 */
/*********************************************************************************************************/
void Reg_Write (uint8_t reg_address, uint8_t data)
{
// MAP_I2C_setSlaveAddress(EUSCI_B0_BASE, HRM_WRITE_ADDRESS);
/* Making sure the last transaction has been completely sent out */
while (MAP_I2C_masterIsStopSent(EUSCI_B0_BASE));
MAP_I2C_masterSendMultiByteStart(EUSCI_B0_BASE, reg_address); // Start + 1Byte
MAP_I2C_masterSendMultiByteFinish(EUSCI_B0_BASE,data);
/*---------------------------------------------*/
}
/**********************************************************************************************************/
/* Reg_Read This function is used to read from the registers in the MAX30102 */
/**********************************************************************************************************/
void Reg_Read(uint8_t Reg_address)
{
reg_data = 0x00;
reg_num = 1;
MAP_I2C_masterSendMultiByteStart(EUSCI_B0_BASE, Reg_address);
MAP_I2C_masterReceiveStart(EUSCI_B0_BASE);
MAP_I2C_enableInterrupt(EUSCI_B0_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0);
}
/*******************************************************************************
* eUSCIB0 ISR. The repeated start and transmit/receive operations happen
* within this ISR.
*******************************************************************************/
void EUSCIB0_IRQHandler(void)
{
uint_fast16_t status;
uint8_t count;
status = MAP_I2C_getEnabledInterruptStatus(EUSCI_B0_BASE);
if (status & EUSCI_B_I2C_RECEIVE_INTERRUPT0)
{
if(reg_num == 1){//reg_num = 1 means we are just reading once from the specified register
//reg_data = MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE);
MAP_I2C_disableInterrupt(EUSCI_B0_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0);
MAP_I2C_masterReceiveMultiByteStop(EUSCI_B0_BASE);
reg_data = MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE);
}
else if (reg_num == 3) //this for loop stores a sample as 3 bytes of data
{
for(count = 0; count < FIFO_DEPTH - 1; count++)
{
fifo_data_r[count] = 0;
fifo_data_ir[count] = 0;
fifo_data_r[count] = MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE) & 3; //to clear unused bits
fifo_data_r[count] = (fifo_data_r[count] << 8) |MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE);
fifo_data_r[count] = (fifo_data_r[count] << 8) |MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE);
}
fifo_data_r[count] = 0;
fifo_data_ir[count] = 0;
fifo_data_r[count] = MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE) & 3;
fifo_data_r[count] = (fifo_data_r[count] << 8) |MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE);
MAP_I2C_disableInterrupt(EUSCI_B0_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0);
MAP_I2C_masterReceiveMultiByteStop(EUSCI_B0_BASE);
fifo_data_r[count] = (fifo_data_r[count] << 8) |MAP_I2C_masterReceiveMultiByteNext(EUSCI_B0_BASE);
ready = 1; //When ready is = 1 the heart rate will be calculated and displayed to the UART
}
}
}
/**********************************************************************************************************/
/* fifo_read This function is used to read from the registers in the MAX30102 and store in the fifo_data array */
/**********************************************************************************************************/
void fifo_read()
{
reg_num = 3;
MAP_I2C_masterSendMultiByteStart(EUSCI_B0_BASE, REG_FIFO_DATA);
MAP_I2C_masterReceiveStart(EUSCI_B0_BASE);
MAP_I2C_enableInterrupt(EUSCI_B0_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0);
}
/**********************************************************************************************************/
/* putsUART This function is used to display a string to the UART */
/**********************************************************************************************************/
void putsUART(char *s)
{
while(*s)
MAP_UART_transmitData(EUSCI_A0_BASE,*s++);
}
/**********************************************************************************************************/
/* init_UART This function is used to initialize to the UART */
/**********************************************************************************************************/
void init_UART()
{
// Selecting P1.2 and P1.3 in UART mode
MAP_GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P1,
GPIO_PIN2 | GPIO_PIN3, GPIO_PRIMARY_MODULE_FUNCTION);
// Setting DCO to 12MHz
CS_setDCOCenteredFrequency(CS_DCO_FREQUENCY_12);
// Configuring UART Module
MAP_UART_initModule(EUSCI_A0_BASE, &uartConfig);
// Enable UART module
MAP_UART_enableModule(EUSCI_A0_BASE);
}
int main(void)
{
/* Stop Watchdog */
MAP_WDT_A_holdTimer();
uint8_t i;
init_I2C();
config_interrupt();
init_UART();
init_MAX();
int peak_diff = 0;
uint16_t peak_index = 0;
float avg_peak_diff = 0;
int sum = 0;
uint16_t peak_num = 0;
uint16_t heart_rate = 0;
int mean = 0;
int mean_Sum = 0;
bool cond1;
bool cond2;
bool cond3;
putsUART("\r\n Senior Design HRM \0");
while(1)
{
if(ready == 1){ //ready becomes 1 after the FIFO has been read three times (see line 316)
ready = 0;
mean = 0;
mean_Sum = 0;
peak_num = 0;
for(i = 0; i < FIFO_DEPTH; i++)
{
mean_Sum = mean_Sum + fifo_data_r[i];
}
mean = mean_Sum/FIFO_DEPTH;
for(i = 1; i < FIFO_DEPTH - 3; i++)//peak detection
{
cond1 = fifo_data_r[i-1] < fifo_data_r[i] && fifo_data_r[i+1] < fifo_data_r[i]; //sharp peak
cond2 = fifo_data_r[i-1] < fifo_data_r[i] && fifo_data_r[i+1] > fifo_data_r[i+2]; //flat peak
cond3 = fifo_data_r[i] > mean; //Ignore peaks below the Average for DC cancellation
if((cond1 || cond2) && cond3) //if the value at index i is a peak
{
peak_num ++;
peak_diff = i - peak_index;
peak_index = i;
if(peak_num > 1)
{
sum = sum + peak_diff;
avg_peak_diff = sum/peak_num;
}
}
}
heart_rate = avg_peak_diff * 2.4; //2.4 = 60 x 0.04. the time between each sample is 0.04s
for (i = 0; i < FIFO_DEPTH; i++) //display ADC data on the uart terminal
{
sprintf(str, "\r\n %d \0",fifo_data_r[i]);
putsUART(str);
}
sprintf(str, "\r\nHeart Rate is %d bpm\0",heart_rate); //display heart rate on terminal
putsUART(str);
putsUART("\r\n\r\n\r\n");
}
else;
}
}```