MAX30101 data collection with MSP430F5438A

munny · September 24, 2018

Hello,

I am trying to get RED, IR and GREEN led value in real time from MAX30101 sensor. I am using MSP430F5438A as my MCU. My IDE is CCS. The protocol required to communicate with the sensor is I2C. Now my problem is I am not any value except 0 in my read and write pointer (Indicated in the comment in my code). I am supposed to get some value in between 0 to 32. I'm attaching the link for the datasheet for the sensor:

https://datasheets.maximintegrated.com/en/ds/MAX30101.pdf
I know the datasheet is a whole lot. But I am referring page 17 which they have a pseudo code how to burst read the FIFO. If anyone already worked with the sensor or anyone know please have a look at it.

#include <msp430.h>

#include <msp430f5438a.h>

#include <string.h>

#define MAX30101_I2C_ADDRESS 0x57

#define MAX30101_REG_INT_STS1 0x00

#define MAX30101_REG_INT_STS2 0x01

#define MAX30101_REG_INT_EN1 0x02

#define MAX30101_REG_INT_EN2 0x03

#define MAX30101_REG_FIFO_WR 0x04

#define MAX30101_REG_FIFO_OVF 0x05

#define MAX30101_REG_FIFO_RD 0x06

#define MAX30101_REG_FIFO_DATA 0x07

#define MAX30101_REG_FIFO_CFG 0x08

#define MAX30101_REG_MODE_CFG 0x09

#define MAX30101_REG_SPO2_CFG 0x0a

#define MAX30101_REG_LED1_PA 0x0c

#define MAX30101_REG_LED2_PA 0x0d

#define MAX30101_REG_LED3_PA 0x0e

#define MAX30101_REG_PILOT_PA 0x10

#define MAX30101_REG_MULTI_LED 0x11

#define MAX30101_REG_TINT 0x1f

#define MAX30101_REG_TFRAC 0x20

#define MAX30101_REG_TEMP_CFG 0x21

#define MAX30101_REG_PROX_INT 0x30

void Clock_setup(); // default

void MAX30101_setup(); // Sensor config setup

void I2C_setup();

void sendByte(char register_add, char data);

int readByte(char wr_add, char rd_add, char register_add);

void burstRead(char wr_add, char rd_add, char register_add, int no_ofsample);

void FIFO_Clear();

char LED1 [96];

char LED2 [96];

char LED3 [96];

long L1[32];

long L2[32];

long L3[32];

int wr;

int rd;

int Ns; // number of available sample

void main()

{

WDTCTL = WDTPW + WDTHOLD;

Clock_setup();

I2C_setup();

_EINT();

MAX30101_setup();

while(1){

//FIFO_Clear();

wr= readByte(0xAE, 0xAF, 0x04); // reading WR_PTR---> I don't know why getting zero

rd= readByte(0xAE, 0xAF, 0x06); // reading RD_PTR---> I don't know why getting zero

Ns = wr-rd;

if(Ns<0){

Ns+=32;

}

if(wr != rd){

burstRead(0xAE, 0xAF, 0x07, Ns);

}

void Clock_setup(){

P11DIR |= BIT2; // check smclk, 1MHz default

P11SEL |= BIT2; // check smclk, 1MHz default

P11DIR |= BIT0; // check aclk, 32.8KHz default

P11SEL |= BIT0; // check aclk, 32.8KHz default

}

void I2C_setup() {

P3SEL |= BIT7; // P3.1(UCB0_SDA), P3.2(UCB0_SCL)

P5SEL |= BIT4;

UCB1CTL1 |= UCSWRST; // reset enable

UCB1CTL0 = UCMST + UCMODE_3 + UCSYNC; // master + I2C mode + Sync

UCB1CTL1 = UCSSEL_2 + UCSWRST; //use SMCLK + still reset

UCB1BR0 = 10; // default SMCLK 1M/10 = 100KHz.........?

UCB1BR1 = 0; //

UCB1I2CSA = MAX30101_I2C_ADDRESS; // MAX30101 7 bit address 0x57

UCB1CTL1 &= ~UCSWRST; // reset clear

// UCB1IE |= UCTXIE + UCRXIE; //TX and RX interrupt enabled

}

//Single Byte Transmit (TX)

void sendByte(char register_add, char data){

// UCB0I2CSA = slave_add; //slave address for transmit mode

UCB1CTL1 |= UCTR + UCTXSTT; // I2C transmit (write) mode + generating START condition

UCB1TXBUF = register_add; //register address to measure temperature/pressure

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

while(UCB1CTL1 & UCTXSTT); //wait till START condition is cleared

UCB1TXBUF = data; //send data to register

while(!(UCB1IFG & UCTXIFG)); //wait until data got sent

UCB1CTL1 |= UCTXSTP; //generate a STOP condition

while(UCB1CTL1 & UCTXSTP); //wait until stop condition got sent

}

//Single Byte Receive (RX)

int readByte(char wr_add, char rd_add, char register_add){

int rx_byte;

//UCB0I2CSA = slave_add; //slave address

UCB1CTL1 |= UCTXSTT + UCTR; // Generating START + I2C transmit (write)

UCB1TXBUF = wr_add; //write register address

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

UCB1TXBUF = register_add; //write register address

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

while( UCB1CTL1 & UCTXSTT); //wait till START condition is cleared

UCB1CTL1 |= UCTXSTT; //generate RE-START

//UCB1I2CSA = slave_add; //slave address

UCB1TXBUF = rd_add; //write register address

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

UCB1CTL1 &=~ UCTR; //receive mode

while( UCB1CTL1 & UCTXSTT); //wait till START condition is cleared

rx_byte = UCB1RXBUF; //read byte

UCB1CTL1 |= UCTXSTP; //generate stop condition

while(UCB1CTL1 & UCTXSTP); //wait till stop condition got sent

return rx_byte;

}

//Multiple Byte Receive (RX)

void burstRead(char wr_add, char rd_add, char register_add, int no_ofsample){

unsigned int i;

//UCB1I2CSA = slave_add; //slave address

//while(!(UCB1IFG & UCTXIFG)); //wait until slave address got sent

UCB1CTL1 |= UCTXSTT + UCTR; // Generating START condition + I2C transmit (write)

UCB1TXBUF = wr_add; //write register address

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

UCB1TXBUF = register_add; //write register address

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

while( UCB1CTL1 & UCTXSTT); //wait till START condition is cleared

UCB1CTL1 |= UCTXSTT; //generate RE-START condition

//UCB1I2CSA = slave_add; //slave address

UCB1TXBUF = rd_add; //write register address

while(!(UCB1IFG & UCTXIFG)); //wait until reg address got sent

UCB1CTL1 &=~ UCTR; //receive mode

while( UCB1CTL1 & UCTXSTT); //wait till START condition is cleared

//buffer[0] = UCB1RXBUF; //dummy read

//while(!(UCB1IFG & UCRXIFG)); //wait till byte is completely read

for(i=0;i<no_ofsample;++i){

LED1 = UCB1RXBUF; //burst read