95 lines
3.3 KiB
C
95 lines
3.3 KiB
C
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/*
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* Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef _spi_h__
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#define _spi_h__
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#include <avr/io.h>
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#ifdef __cplusplus
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extern "C"{
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#endif
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// create alias for the different SPI chip pins - code assumes all on port B
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#if (defined(__AVR_AT90USB82__) || defined(__AVR_AT90USB162__))
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#define SPI_SS_PIN PORTB0
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#define SPI_SCK_PIN PORTB1
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#define SPI_MOSI_PIN PORTB2
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#define SPI_MISO_PIN PORTB3
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#elif (defined(__AVR_ATmega48__) || defined(_AVR_ATmega88__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega328__) || defined(__AVR_ATmega328P__))
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#define SPI_SS_PIN PORTB2
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#define SPI_SCK_PIN PORTB5
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#define SPI_MOSI_PIN PORTB3
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#define SPI_MISO_PIN PORTB4
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#else
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#error unknown processor - add to spi.h
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#endif
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// SPI clock modes
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#define SPI_MODE_0 0x00 /* Sample (Rising) Setup (Falling) CPOL=0, CPHA=0 */
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#define SPI_MODE_1 0x01 /* Setup (Rising) Sample (Falling) CPOL=0, CPHA=1 */
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#define SPI_MODE_2 0x02 /* Sample (Falling) Setup (Rising) CPOL=1, CPHA=0 */
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#define SPI_MODE_3 0x03 /* Setup (Falling) Sample (Rising) CPOL=1, CPHA=1 */
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// data direction
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#define SPI_LSB 1 /* send least significant bit (bit 0) first */
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#define SPI_MSB 0 /* send most significant bit (bit 7) first */
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// whether to raise interrupt when data received (SPIF bit received)
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#define SPI_NO_INTERRUPT 0
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#define SPI_INTERRUPT 1
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// slave or master with clock diviser
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#define SPI_SLAVE 0xF0
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#define SPI_MSTR_CLK4 0x00 /* chip clock/4 */
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#define SPI_MSTR_CLK16 0x01 /* chip clock/16 */
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#define SPI_MSTR_CLK64 0x02 /* chip clock/64 */
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#define SPI_MSTR_CLK128 0x03 /* chip clock/128 */
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#define SPI_MSTR_CLK2 0x04 /* chip clock/2 */
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#define SPI_MSTR_CLK8 0x05 /* chip clock/8 */
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#define SPI_MSTR_CLK32 0x06 /* chip clock/32 */
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// setup spi
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void setup_spi(uint8_t mode, // timing mode SPI_MODE[0-4]
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int dord, // data direction SPI_LSB|SPI_MSB
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int interrupt, // whether to raise interrupt on recieve
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uint8_t clock); // clock diviser
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// disable spi
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void disable_spi(void);
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// send and receive a byte of data (master mode)
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uint8_t send_spi(uint8_t out);
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// receive the byte of data waiting on the SPI buffer and
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// set the next byte to transfer - for use in slave mode
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// when interrupts are enabled.
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uint8_t received_from_spi(uint8_t out);
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#ifdef __cplusplus
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} // extern "C"
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#endif
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#endif
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