示例#1
0
/**
 * Reads multiple bytes from a register.
 *
 * @param reg register to read from.
 * @param count number of bytes to read.
 * @param values target buffer.
 * @return pointer to the input buffer + count.
 */
uint8_t * max3421e_readMultiple(uint8_t reg, uint8_t count, uint8_t * values)
{
    // Pull slave-select high to initiate transfer.
    MAX_SS(0);

    // Send a command byte containing the register number.
    SPDR = reg;
    while (!(SPSR & (1 << SPIF))); //wait

    // Read [count] bytes.
    while (count--)
    {
        // Send empty byte while reading.
        SPDR = 0;
        while (!(SPSR & (1 << SPIF)));

        *values = SPDR;
        values++;
    }

    // Pull slave-select low to signal transfer complete.
    MAX_SS(1);

    // Return the byte array + count.
    return (values);
}
示例#2
0
文件: max3421e.c 项目: ehujair/vivus
/*
 * Initialises the max3421e host shield. Initialises the SPI bus and sets the required pin directions.
 * Must be called before powerOn.
 */
void max3421e_init()
{
	spi_begin();

#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)

	// Set MAX_INT and MAX_GPX pins to input mode.
	DDRH &= ~(0x40 | 0x20);

	// Set SPI !SS pint to output mode.
	DDRB |= 0x10;

	// Set RESET pin to output
	DDRH |= 0x10;

#elif defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__)

	// Set MAX_INT and MAX_GPX pins to input mode.
	DDRB &= ~0x3;

	// Set RESET pin to output
	DDRD |= 0x80;

	// Set SS pin to output
	DDRB |= 0x4;

#endif

	// Sparkfun botched their first attempt at cloning Oleg's max3421e shield and reversed the GPX and RESET pins.
	// This hack is in place to make MicroBridge work with those shields. (see http://www.sparkfun.com/products/9628)
#ifdef SFHACK

#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)

	// Set MAX_GPX pin to input mode.
	DDRH &= ~0x10;

	// Set RESET pin to output
	DDRH |= 0x20;

#elif defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__)

	// Set GPX pin to input
	DDRD &= ~0x80;

	// Set RESET pin to output
	DDRB |= 0x1;

#endif

#endif


	// Pull SPI !SS high
	MAX_SS(1);

	// Reset
	MAX_RESET(1);
}
示例#3
0
/**
 * Writes a single register.
 *
 * @param reg register address.
 * @param value value to write.
 */
void max3421e_write(uint8_t reg, uint8_t value)
{
    // Pull slave select low to indicate start of transfer.
    MAX_SS(0);

    // Transfer command byte, 0x02 indicates write.
    SPDR = (reg | 0x02);
    while (!(SPSR & (1 << SPIF)));

    // Transfer value byte.
    SPDR = value;
    while (!(SPSR & (1 << SPIF)));

    // Pull slave select high to indicate end of transfer.
    MAX_SS(1);

    return;
}
示例#4
0
/**
 * Reads a single register.
 *
 * @param reg register address.
 * @return result value.
 */
uint8_t max3421e_read(uint8_t reg)
{
    // Pull slave-select high to initiate transfer.
    MAX_SS(0);

    // Send a command byte containing the register number.
    SPDR = reg;
    while (!(SPSR & (1 << SPIF)));

    // Send an empty byte while reading.
    SPDR = 0;
    while (!(SPSR & (1 << SPIF)));

    // Pull slave-select low to signal transfer complete.
    MAX_SS(1);

    // Return result byte.
    return (SPDR);
}
示例#5
0
/*
 * Initialises the max3421e host shield. Initialises the SPI bus and sets the required pin directions.
 * Must be called before powerOn.
 */
void max3421e_init()
{

    SPI.begin();

#ifndef __AVR_ATmega2560__
    pinMode(PIN_MAX_INT, INPUT);
    pinMode(PIN_MAX_GPX, INPUT);
    pinMode(PIN_MAX_SS, OUTPUT);
    pinMode(PIN_MAX_RESET, OUTPUT);
#endif
#ifdef __AVR_ATmega2560__
    pinMode(PIN_MAX_SS, OUTPUT);
    DDRE &= ~ 0x40; // MAX_INT as input
    DDRJ &= ~ 0x08; //MAX_GPX as input
    DDRJ |= 0x04; //MAX_RESET as output
#endif


    /*
    #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)

    	// Set MAX_INT and MAX_GPX pins to input mode.
    	DDRH &= ~(0x40 | 0x20);

    	// Set SPI !SS pint to output mode.
    	DDRB |= 0x10;

    	// Set RESET pin to output
    	DDRH |= 0x10;

    #elif defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__)

    	// Set MAX_INT and MAX_GPX pins to input mode.
    	DDRB &= ~0x3;

    	// Set RESET pin to output
    	DDRD |= 0x80;

    	// Set SS pin to output
    	DDRB |= 0x4;

    #endif
    */

    // Pull SPI !SS high
    MAX_SS(1);

    // Reset
    MAX_RESET(1);
}
示例#6
0
/**
 * Writes multiple bytes to a register.
 * @param reg register address.
 * @param count number of bytes to write.
 * @param vaues input values.
 * @return a pointer to values, incremented by the number of bytes written (values + length).
 */
uint8_t * max3421e_writeMultiple(uint8_t reg, uint8_t count, uint8_t * values)
{
    // Pull slave select low to indicate start of transfer.
    MAX_SS(0);

    // Transfer command byte, 0x02 indicates write.
    SPDR = (reg | 0x02);
    while (!(SPSR & (1 << SPIF)));

    // Transfer values.
    while (count--)
    {
        // Send next value byte.
        SPDR = (*values);
        while (!(SPSR & (1 << SPIF)));

        values++;
    }

    // Pull slave select high to indicate end of transfer.
    MAX_SS(1);

    return (values);
}