forked from ethersex/ethersex
/
soft_spi.c
52 lines (43 loc) · 1.3 KB
/
soft_spi.c
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/*
* Copyright(C) 2010 by Stefan Siegl <stesie@brokenpipe.de>
*
* 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 3 of the License, or
* (at your option) any later version.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* For more information on the GPL, please go to:
* http://www.gnu.org/copyleft/gpl.html
*/
#include "config.h"
#include <avr/io.h>
uint8_t
spi_send(uint8_t outdata)
{
DDR_CONFIG_IN(SOFT_SPI_MISO);
uint8_t j, indata = indata;
for(j = 0; j < 8; j++)
{
if(outdata & 0x80)
PIN_SET(SOFT_SPI_MOSI);
else
PIN_CLEAR(SOFT_SPI_MOSI);
PIN_SET(SOFT_SPI_SCK);
indata <<= 1;
if(PIN_HIGH(SOFT_SPI_MISO))
indata |= 1;
PIN_CLEAR(SOFT_SPI_SCK);
outdata <<= 1;
}
DDR_CONFIG_OUT(SOFT_SPI_MISO);
return indata;
}