ADXL355.cpp

#include "ADXL355.h"

void ADXL355::spi_writebyte(byte address, byte toWrite)
{
    SPI.beginTransaction(settings);
    setCS(true);

    SPI.transfer((address << 1) | AXL355__SPI_WRITEBIT);
    SPI.transfer(toWrite);

    setCS(false);
    SPI.endTransaction();
}

byte ADXL355::spi_readbyte(byte address)
{
    byte result = 0x0;
    SPI.beginTransaction(settings);
    setCS(true);

    SPI.transfer((address << 1) | AXL355__SPI_READBIT);
    result = SPI.transfer(0x00);

    setCS(false);
    SPI.endTransaction();
    return result;
}

void ADXL355::spi_multibyte_read(byte *buf, int buffersize, byte startaddress)
{
    SPI.beginTransaction(settings);
    setCS(true);

    SPI.transfer((byte)((startaddress << 1) | AXL355__SPI_READBIT));
    for (int i = 0; i < buffersize; i++) {
        buf[i] = SPI.transfer(0x0);
    }

    setCS(false);
    SPI.endTransaction();
}

boolean ADXL355::begin(byte range, byte filter = ADXL355_FILTER_OFF)
{
    this->range = range;
    pinMode(chipselect, OUTPUT);
    if (chipselect2 >= 0) {
        pinMode(chipselect2, OUTPUT);
    }
    digitalWrite(chipselect, LOW);

    spi_writebyte(ADXL355__REG_RESET, 0x00);
    spi_writebyte(ADXL355__REG_RANGE, range);
    spi_writebyte(ADXL355__REG_FILTER, filter);
    spi_writebyte(ADXL355__REG_POWER_CONTROL, AXL355__CONST_MEASURE_MODE);
    byte adbyte = spi_readbyte(0x00);

    digitalWrite(chipselect, HIGH);
    return adbyte == 0xAD;
}

void ADXL355::takeSample()
{
    byte bytebuf[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
    spi_multibyte_read(bytebuf, 9, ADXL355__REG_ACCELEROMETER_DATA_BEGIN);

    unsigned long buf[9];
    for (int i = 0; i < 9; i++)
        buf[i] = (int)bytebuf[i];

    axes[0] = (buf[2] | buf[1] << 8 | buf[0] << 16) & 0xFFFFFF;
    axes[1] = (buf[5] | buf[4] << 8 | buf[3] << 16) & 0xFFFFFF;
    axes[2] = (buf[8] | buf[7] << 8 | buf[6] << 16) & 0xFFFFFF;
    long mask = 1;
    mask = mask << 23;

    for (int i = 0; i < 3; i++) {
        if (axes[i] > mask) {
            axes[i] = -((mask << 1) - axes[i]);
        }
    }
}

ADXL355Measurement ADXL355::getSample()
{
    long scale = ((long)2 << ((3 - range) + 5)) * 1000;
    ADXL355Measurement measure;
    measure.x = axes[0] / (1.0 * scale);
    measure.y = axes[1] / (1.0 * scale);
    measure.z = axes[2] / (1.0 * scale);

    return measure;
}

byte ADXL355::getStatus() { return spi_readbyte(ADXL255__REG_STATUS); }

void ADXL355::setCS(bool active)
{
    digitalWrite(chipselect, !active);
    if (chipselect2 >= 0) {
        digitalWrite(chipselect2, !active);
    }
}