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/****************************************************************************
* Copyright (C) 2009-2013 by Claas Anders "CaScAdE" Rathje *
* admiralcascade@gmail.com *
* Project-URL: http://www.mylifesucks.de/oss/c-osd/ *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
****************************************************************************/
#include "main.h"
#include <avr/io.h>
#include <avr/interrupt.h>
#include "spi.h"
#if !(ALLCHARSDEBUG|(WRITECHARS != -1))
volatile uint16_t icnt = 0;
volatile uint8_t request_count = 0;
volatile uint8_t spi_ready = 1;
volatile union SPI_buffer_t SPI_buffer;
int16_t ampere = 0, max_ampere = 0, s_volt;
int32_t ampere_wasted = 0;
#define INT0_HIGH PORTD |= (1 << PD2);
#define INT0_LOW PORTD &= ~(1 << PD2);
/**
* init the SPI as master
*/
void SpiMasterInit(void) {
volatile char IOReg;
// set PB4(/SS), PB5(MOSI), PB7(SCK) as output
DDRB = (1 << PB4) | (1 << PB5) | (1 << PB7);
PORTB |= (1 << PB4); // pullup SS
// enable SPI Interrupt and SPI in Master Mode with SCK = CK/128
SPCR = (1 << SPIE) | (1 << SPE) | (1 << MSTR) | (1 << SPR0) | (1 << SPR1);
IOReg = SPSR; // clear SPIF bit in SPSR
IOReg = SPDR;
//sei(); // we do it later
}
/**
* SPI interrupt handler
*/
ISR(SPI_STC_vect) {
if (request_count == 0) {
SPI_buffer.buffer.chk = SPDR; // firs char received is check byte from last transfer
} else {
SPI_buffer.buffer.c[request_count - 1] = SPDR; // safe received byte to buffer
}
request_count++;
if (--icnt) {
//SPDR = *iptr; // send next byte
spi_ready = 1; // we _should_ send later because the slave needs more time
} else {
SPCR &= ~_BV(SPIE); // deactivate interrupt
INT0_HIGH // transfer is done, slave does not need to listen
}
}
/**
* check if SPI transfer is still busy
*/
int TransferIsBusy(void) {
return SPCR & _BV(SPIE);
}
/**
* start a new transfer with length <len>
*/
void StartTransfer(uint16_t len) {
INT0_LOW // /SS LOW ^= SS HIGH ^= slave should listen
// this is a new request
request_count = 0;
// set up pointer and length for interrupt handler
icnt = len;
SPCR |= _BV(SPIE); // enable spi interrupt
SPDR = 'A'; // start transfer by first command char
}
/**
* send next command through spi
*/
void spi_send_next() {
SPDR = 'A' + request_count;
}
#endif