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248 Kevin 1 
#include "adxl345.h"
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#include "hal_hardware_board.h"
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#include "hal_SPI.h"
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/*
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 * Writes the given byte to the register at the address
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 */
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void WriteSPI(unsigned char addr, unsigned char data) {
251 Kevin 9 
	halSPISetPolarityPhase(1,1);		// ADXL345 operates in SPI(1,1)
248 Kevin 10 
	ADXL_CS_LOW();
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	spiSendByte(addr & ~ADXL_BYTE_WRITE);
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	spiSendByte(data);
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	ADXL_CS_HIGH();
251 Kevin 14 
	halSPISetPolarityPhase(0,0);		// Revert back to SPI(0,0)
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}
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/*
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 * Reads the value of the register at the address
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 */
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unsigned char ReadSPI(unsigned char addr) {
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	unsigned char ret;
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	halSPISetPolarityPhase(1,1);		// ADXL345 operates in SPI(1,1)
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	ADXL_CS_LOW();
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	spiSendByte(addr | ADXL_BYTE_READ);
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	spiReadFrame(&ret, 1);
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	ADXL_CS_HIGH();
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	halSPISetPolarityPhase(0,0);		// Revert back to SPI(0,0)
248 Kevin 28 
	return ret;
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}
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/*
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 * Reads a 16-bit value of the register at the address
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 */
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int Read16SPI(unsigned char addr) {
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	unsigned char recv[2];
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	int ret;
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	halSPISetPolarityPhase(1,1);		// ADXL345 operates in SPI(1,1)
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	ADXL_CS_LOW();
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	spiSendByte(addr | ADXL_MULTI_BYTE_READ);
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	spiReadFrame(recv, 2);
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	ADXL_CS_HIGH();
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	halSPISetPolarityPhase(0,0);		// Revert back to SPI(0,0)
248 Kevin 43 
	ret = recv[0];
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	ret |= recv[1] << 8;
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	return ret;
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}
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/*
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 * ADXL345 Initialization Function
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 */
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unsigned char ADXLInit(void) {
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	unsigned char deviceID;
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	// Check if device exists
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	deviceID = ReadSPI(ADXL345_REG_DEVID);
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	if (deviceID != 0xE5)
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		return 1;
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	// Set FIFO to bypass mode
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	WriteSPI(ADXL345_REG_FIFO_CTL, 0x00);
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//	// Set the INT_INVERT bit in DATA_FORMAT register
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	WriteSPI(ADXL345_REG_DATA_FORMAT, 0x20);
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	ADXLSetRange(ADXL345_RANGE_16_G);
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	ADXLSetDataRate(ADXL345_DATARATE_12_5_HZ);
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	ADXLClearInterrupts();
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	ADXLStandbyOff();
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	return 0;
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}
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void ADXLStandbyOn(void) {
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	// Turn off measurements
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	WriteSPI(ADXL345_REG_POWER_CTL, 0x00);
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}
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void ADXLStandbyOff(void) {
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	// Turn on measurements
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	WriteSPI(ADXL345_REG_POWER_CTL, 0x08);
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}
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/*
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 * Sets up and enables the tap interrupt
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 */
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void ADXLInitInterrupts(void) {
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	// Set tap acceleration threshold  (62.5mg/LSB, 0xFF=16g)
251 Kevin 91 
	WriteSPI(ADXL345_REG_THRESH_TAP, 0x18);
248 Kevin 92 
 
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	// Set maximum tap duration (625us/LSB)
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	WriteSPI(ADXL345_REG_DUR, 0xFF);
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	// Set minimum time for second tap (1.25ms/LSB)
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	WriteSPI(ADXL345_REG_LATENT, 0xFF);
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	// Set maximum time for second tap (1.25ms/LSB)
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	WriteSPI(ADXL345_REG_WINDOW, 0xFF);
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	// Bind single tap to INT1 and double tap to INT2
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	WriteSPI(ADXL345_REG_INT_MAP, 0x20);
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	// Enable all three axis for tap detection
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	WriteSPI(ADXL345_REG_TAP_AXES, 0x07);
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	// Enable single tap interrupts
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	WriteSPI(ADXL345_REG_INT_ENABLE, 0x40);
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}
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/*
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 * Clears any active interrupt flags
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 */
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void ADXLClearInterrupts(void) {
251 Kevin 116 
	ReadSPI(ADXL345_REG_ACT_TAP_STATUS);
248 Kevin 117 
	ReadSPI(ADXL345_REG_INT_SOURCE);
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}
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/*
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 * Returns sensor data
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 */
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void ADXLRead(int *x, int *y, int *z) {
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	*x = Read16SPI(ADXL345_REG_DATAX0);
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	*y = Read16SPI(ADXL345_REG_DATAY0);
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	*z = Read16SPI(ADXL345_REG_DATAZ0);
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}
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/*
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 * Sets the sensitivity range (2/4/8/16g)
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 */
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void ADXLSetRange(range_t range) {
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	unsigned char data = ReadSPI(ADXL345_REG_DATA_FORMAT);
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	// Set the new sensitivity range
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	data &= ~0x0F;
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	data |= range;
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	// Set the FULL_RES bit
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	data |= 0x08;
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	WriteSPI(ADXL345_REG_DATA_FORMAT, data);
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}
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/*
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 * Sets the data rate
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 */
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void ADXLSetDataRate(dataRate_t rate) {
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	unsigned char data = rate;
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#ifdef ADXL345_LOW_POWER_MODE
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	// Set the low power mode bit
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	data |= 0x10;
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#endif
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	WriteSPI(ADXL345_REG_BW_RATE, data);
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}