CCS/LAUNCHXL-CC26X2R1: LAUNCHXL-CC26X2R1 SPI not working with Accelerometer

// 3-axis Accelerometer
// SMicroelectronics IIS3DHH 
// Arduino Nano

// IIS3DHH Initilization
#include <SPI.h>

#define SS 10 // Serial Select -> CS on IIS3DHH
#define MOSI 11 // MasterOutSlaveIn -> SDI
#define MISO 12 // MasterInSlaveOut -> SDO
#define SCK 13 // Serial Clock -> SPC on IIS3DHH

#define SCALE_I 0.076294;
// scale factor: +/- 2.5G full range = 5000mG total range / 65536 counts (16 bit)
int n = 25; // number of samples
int x_I,y_I,z_I;  // the sensor values
int i = 0;
int j = 0;

double xA_I, yA_I, zA_I;

void setup() {
  
  pinMode(SS, OUTPUT);
  digitalWrite(SS,HIGH);
// Serial.begin(9600);
  SPI.begin();
  Serial.begin(9600);
// IIS3DHH Initilization
  Accelerometer_Setup();
  
delay(1000);
}

void loop() {
// IIS3DHH read values
  double zMin_I = 32767;  // minimum sensor value
  double zMax_I = -32767;     // maximum sensor value
  float zTotal_I = 0;
  float zAvg_I = 0;

  readValWho_Am_I();
  
  while (i<n) { 
  
  readVal(); // get acc values and put into global variables
  
// Print ISS3DHH values    
  Serial.print("xA_I = ");
  Serial.print(xA_I, 2);
  Serial.print('\t');
  Serial.print("yA_I = ");
  Serial.print(yA_I, 2);
  Serial.print('\t');
  Serial.print("zA_I = ");
  Serial.println(zA_I, 2);

  delay(10); // Adjust for sampling rate (e.g. 10mS = 100Hz. 2mS = 500Hz etc.)

// record the maximum sensor_I value
  if (zA_I > zMax_I) {
    zMax_I = zA_I;
    }
// record the minimum sensor_I value
  if (zA_I < zMin_I) {
    zMin_I = zA_I;
    }
  zTotal_I = zTotal_I + zA_I;

  i++;
  }
// Calculate Average
  zAvg_I = zTotal_I/i;
  
// Print ISS3DHH values       
  Serial.println("zAMax_I = " + String(zMax_I)+" mg");
  Serial.println("zAMin_I = " + String(zMin_I)+" mg");
  Serial.println("zA(Max-Min)_I = " + String(zMax_I-zMin_I)+" mg");
  Serial.println("zAAvg_I = " + String(zAvg_I)+" mg");
  
  delay(2000);
  i = 0;
}

//=========== READ IIS3DHHC REGISTERS ==========
void readVal()
{
byte xAddressByteL = 0x28; // Low Byte of X value (the first data register)
byte readBit = B10000000; // bit 0 (MSB) HIGH means read register, 
byte dataByte = xAddressByteL | readBit;
byte b0 = 0x0; // an empty byte to initiate read register
//Serial.println("read request:");
//Serial.println(dataByte);

SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));
digitalWrite(SS, LOW); // SS must be LOW to communicate
//delay(10);
SPI.transfer(dataByte); // request a read, starting at X low byte
byte xL = SPI.transfer(b0); // get the low byte of X data
byte xH = SPI.transfer(b0); // get the high byte of X data
byte yL = SPI.transfer(b0); // get the low byte of Y data
byte yH = SPI.transfer(b0); // get the high byte of Y data
byte zL = SPI.transfer(b0); // get the low byte of Z data
byte zH = SPI.transfer(b0); // get the high byte of Z data
//delay(10);
digitalWrite(SS, HIGH);
SPI.endTransaction();

// shift the high byte left 8 bits and merge the high and low
int xVal = (xL | (xH << 8));
int yVal = (yL | (yH << 8));
int zVal = (zL | (zH << 8));

// scale the values into mG
xA_I = xVal * SCALE_I;
yA_I = yVal * SCALE_I;
zA_I = zVal * SCALE_I;
}

//=========== SETUP IIS3DHHC ==========
void Accelerometer_Setup()
{

// write to Control register 1: address 20h
byte addressByte = 0x20;
byte ctrlRegByte = 0xC0; // 0xC0 = 1100 0000 : normal mode, incremented addressing // 0x80 = normal mode, do not increment

SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));
digitalWrite(SS, LOW);
delay(10);
SPI.transfer(addressByte);
SPI.transfer(ctrlRegByte);
delay(10);
digitalWrite(SS, HIGH);
SPI.endTransaction();

delay(100);

// write to Control Register 4: address 23h
addressByte = 0x23;
// This register configures filter and bandwidth
ctrlRegByte = 0x00; // FIR Linear Phase, 440Hz

SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));
digitalWrite(SS, LOW);
delay(10);
SPI.transfer(addressByte);
SPI.transfer(ctrlRegByte);
delay(10);
digitalWrite(SS, HIGH);
SPI.endTransaction();

delay(1000);
}

//=========== READ Who_Am_I REGISTER ==========
void readValWho_Am_I()
{
byte xAddressByteL = 0x0F; // Address of Who_Am_I register
byte readBit = B10000000; // bit 0 (MSB) HIGH means read register, 
byte dataByte = xAddressByteL | readBit;
byte b0 = 0x0; // an empty byte to initiate read register
//Serial.println("read request:");
//Serial.println(dataByte);

SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));
digitalWrite(SS, LOW); // SS must be LOW to communicate
//delay(10);
SPI.transfer(dataByte); // request a read, starting at X low byte
byte xL = SPI.transfer(b0); // get the low byte of X data

//delay(10);
digitalWrite(SS, HIGH);
SPI.endTransaction();

Serial.print("Who_Am_I = ");
Serial.println(xL);
}

/*
 * Copyright (c) 2018-2019, Texas Instruments Incorporated
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * *  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 * *  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * *  Neither the name of Texas Instruments Incorporated nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 *  ======== spimaster.c ========
 */
#include <stddef.h>
#include <stdint.h>
#include <string.h>

/* POSIX Header files */
#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>

/* Driver Header files */
#include <ti/drivers/GPIO.h>
#include <ti/drivers/SPI.h>
#include <ti/display/Display.h>

/* Driver configuration */
#include "ti_drivers_config.h"

#define THREADSTACKSIZE (1024)

#define SPI_MSG_LENGTH  (30)
#define MASTER_MSG      ("Hello from master, msg#: ")

#define MAX_LOOP        (10)

static Display_Handle display;

// unsigned char masterRxBuffer[SPI_MSG_LENGTH];
// unsigned char masterTxBuffer[SPI_MSG_LENGTH];

int masterRxBuffer[SPI_MSG_LENGTH];
int masterTxBuffer[SPI_MSG_LENGTH];

/* Semaphore to block master until slave is ready for transfer */
sem_t masterSem;

/*
 *  ======== slaveReadyFxn ========
 *  Callback function for the GPIO interrupt on CONFIG_SPI_SLAVE_READY.
 */
void slaveReadyFxn(uint_least8_t index)
{
    sem_post(&masterSem);
}

/*
 *  ======== masterThread ========
 *  Master SPI sends a message to slave while simultaneously receiving a
 *  message from the slave.
 */
void *masterThread(void *arg0)
{
    SPI_Handle      masterSpi;
    SPI_Params      spiParams;
    SPI_Transaction transaction;
    uint32_t        i;
    bool            transferOK;
    int32_t         status;

    /*
     * CONFIG_SPI_MASTER_READY & CONFIG_SPI_SLAVE_READY are GPIO pins connected
     * between the master & slave.  These pins are used to synchronize
     * the master & slave applications via a small 'handshake'.  The pins
     * are later used to synchronize transfers & ensure the master will not
     * start a transfer until the slave is ready.  These pins behave
     * differently between spimaster & spislave examples:
     *
     * spimaster example:
     *     * CONFIG_SPI_MASTER_READY is configured as an output pin.  During the
     *       'handshake' this pin is changed from low to high output.  This
     *       notifies the slave the master is ready to run the application.
     *       Afterwards, the pin is used by the master to notify the slave it
     *       has opened CONFIG_SPI_MASTER.  When CONFIG_SPI_MASTER is opened, this
     *       pin will be pulled low.
     *
     *     * CONFIG_SPI_SLAVE_READY is configured as an input pin. During the
     *       'handshake' this pin is read & a high value will indicate the slave
     *       ready to run the application.  Afterwards, a falling edge interrupt
     *       will be configured on this pin.  When the slave is ready to perform
     *       a transfer, it will pull this pin low.
     *
     * Below we set CONFIG_SPI_MASTER_READY & CONFIG_SPI_SLAVE_READY initial
     * conditions for the 'handshake'.
     */
    GPIO_setConfig(CONFIG_SPI_MASTER_READY, GPIO_CFG_OUTPUT | GPIO_CFG_OUT_LOW);
    GPIO_setConfig(CONFIG_SPI_SLAVE_READY, GPIO_CFG_INPUT);

    /*
     * Handshake - Set CONFIG_SPI_MASTER_READY high to indicate master is ready
     * to run.  Wait CONFIG_SPI_SLAVE_READY to be high.
     */
    GPIO_write(CONFIG_SPI_MASTER_READY, 1);
    while (GPIO_read(CONFIG_SPI_SLAVE_READY) == 0) {}

    /* Handshake complete; now configure interrupt on CONFIG_SPI_SLAVE_READY */
    GPIO_setConfig(CONFIG_SPI_SLAVE_READY, GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_FALLING);
    GPIO_setCallback(CONFIG_SPI_SLAVE_READY, slaveReadyFxn);
    GPIO_enableInt(CONFIG_SPI_SLAVE_READY);

    /*
     * Create synchronization semaphore; the master will wait on this semaphore
     * until the slave is ready.
     */
    status = sem_init(&masterSem, 0, 0);
    if (status != 0) {
        Display_printf(display, 0, 0, "Error creating masterSem\n");

        while(1);
    }

    /* Open SPI as master (default) */
    SPI_Params_init(&spiParams);
    spiParams.frameFormat = SPI_POL0_PHA1;
//    spiParams.bitRate = 4000000;
    spiParams.bitRate = 1000000; // My change
    masterSpi = SPI_open(CONFIG_SPI_MASTER, &spiParams);
    if (masterSpi == NULL) {
        Display_printf(display, 0, 0, "Error initializing master SPI\n");
        while (1);
    }
    else {
        Display_printf(display, 0, 0, "Master SPI initialized\n");
    }

    /*
     * Master has opened CONFIG_SPI_MASTER; set CONFIG_SPI_MASTER_READY high to
     * inform the slave.
     */
    GPIO_write(CONFIG_SPI_MASTER_READY, 0);

    /* Copy message to transmit buffer */
    strncpy((char *) masterTxBuffer, MASTER_MSG, SPI_MSG_LENGTH);

    for (i = 0; i < MAX_LOOP; i++) {
        /*
         * Wait until slave is ready for transfer; slave will pull
         * CONFIG_SPI_SLAVE_READY low.
         */
     //   sem_wait(&masterSem); // My change

        /* Initialize master SPI transaction structure */
     //   masterTxBuffer[sizeof(MASTER_MSG) - 1] = (i % 10) + '0';
        masterTxBuffer[0] = 0x0F;
        memset((void *) masterRxBuffer, 0, SPI_MSG_LENGTH);
    //    transaction.count = SPI_MSG_LENGTH;
        transaction.count = 2;
        transaction.txBuf = (void *) masterTxBuffer;
        transaction.rxBuf = (void *) masterRxBuffer;

        /* Toggle user LED, indicating a SPI transfer is in progress */
        GPIO_toggle(CONFIG_GPIO_LED_1);

        /* Perform SPI transfer */
        transferOK = SPI_transfer(masterSpi, &transaction);
        if (transferOK) {
          //  Display_printf(display, 0, 0, "Master received: %s", masterRxBuffer);
            Display_printf(display, 0, 0, "Master received: %d", masterRxBuffer);
        }
        else {
            Display_printf(display, 0, 0, "Unsuccessful master SPI transfer");
        }

        /* Sleep for a bit before starting the next SPI transfer  */
        sleep(3);
    }

    SPI_close(masterSpi);

    /* Example complete - set pins to a known state */
    GPIO_disableInt(CONFIG_SPI_SLAVE_READY);
    GPIO_setConfig(CONFIG_SPI_SLAVE_READY, GPIO_CFG_OUTPUT | GPIO_CFG_OUT_LOW);
    GPIO_write(CONFIG_SPI_MASTER_READY, 0);

    Display_printf(display, 0, 0, "\nDone");

    return (NULL);
}

/*
 *  ======== mainThread ========
 */
void *mainThread(void *arg0)
{
    pthread_t           thread0;
    pthread_attr_t      attrs;
    struct sched_param  priParam;
    int                 retc;
    int                 detachState;

    /* Call driver init functions. */
    Display_init();
    GPIO_init();
    SPI_init();

    /* Configure the LED pins */
    GPIO_setConfig(CONFIG_GPIO_LED_0, GPIO_CFG_OUT_STD | GPIO_CFG_OUT_LOW);
    GPIO_setConfig(CONFIG_GPIO_LED_1, GPIO_CFG_OUT_STD | GPIO_CFG_OUT_LOW);

    /* Open the display for output */
    display = Display_open(Display_Type_UART, NULL);
    if (display == NULL) {
        /* Failed to open display driver */
        while (1);
    }

    /* Turn on user LED */
    GPIO_write(CONFIG_GPIO_LED_0, CONFIG_GPIO_LED_ON);

    Display_printf(display, 0, 0, "Starting the SPI master example");
    Display_printf(display, 0, 0, "This example requires external wires to be "
        "connected to the header pins. Please see the Board.html for details.\n");

    /* Create application threads */
    pthread_attr_init(&attrs);

    detachState = PTHREAD_CREATE_DETACHED;
    /* Set priority and stack size attributes */
    retc = pthread_attr_setdetachstate(&attrs, detachState);
    if (retc != 0) {
        /* pthread_attr_setdetachstate() failed */
        while (1);
    }

    retc |= pthread_attr_setstacksize(&attrs, THREADSTACKSIZE);
    if (retc != 0) {
        /* pthread_attr_setstacksize() failed */
        while (1);
    }

    /* Create master thread */
    priParam.sched_priority = 1;
    pthread_attr_setschedparam(&attrs, &priParam);

    retc = pthread_create(&thread0, &attrs, masterThread, NULL);
    if (retc != 0) {
        /* pthread_create() failed */
        while (1);
    }

    return (NULL);
}