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usiTwiSlave.h
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usiTwiSlave.h
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/*##############################################################################
Name : USI TWI Slave driver - I2C/TWI-EEPROM
Version : 1.3 - Stable
autor : Martin Junghans jtronics@gmx.de
page : www.jtronics.de
License : GNU General Public License
Created from Atmel source files for Application Note AVR312:
Using the USI Module as an I2C slave like an I2C-EEPROM.
LICENSE: Copyright (C) 2010 Marin Junghans
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, or
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
16.11.2010 - reworked by Markus Schatzl
//##############################################################################
Description:
The slave device acts like a I2C-EEPROM.
Write data from master to slave (into slave rxbuffer):
1. Master sends slave address (bit 7-1) + r/w flag (bit 0), which must be set to 0
2. Master sends address of where to start with writing data (one byte)
3. Master sends data to rxbuffer[buffer address]
Read data from the slave (from slave txbuffer):
1. Master sends slave address (bit 7-1) + r/w flag (bit 0), which must be set to 0
2. Master sends address of where to start reading data (one byte)
3. Master sends slave address (bit 7-1) + r/w flag (bit 0), which must be set to 1
4. Master waits for callback, demanding the slave to send data starting with txbuffer[buffer address]
Info:
- You have to change the buffer_size in the usiTwiSlave.h file
- Buffer address is automatically incremented
- If buffer address > buffersize -> start with buffer address 0x00
//############################################################################*/
#ifndef _USI_TWI_SLAVE_H_
#define _USI_TWI_SLAVE_H_
//##################################################################### includes
#include <stdbool.h>
//################################################################### prototypes
void usiTwiSlaveInit(uint8_t ownAddress); // send slave address
//#################################################################### variables
#define buffer_size 15 //in bytes (2..254), change ONLY here!!!!!
//volatile uint8_t rxbuffer[buffer_size]; // Buffer to write data received from the master
//volatile uint8_t txbuffer[buffer_size]; // Transmission buffer to be read from the master
volatile uint8_t twibuffer[buffer_size];
volatile uint8_t buffer_adr; // Virtual buffer address register
#if (buffer_size > 254)
#error Buffer to big! Maximal 254 Bytes.
#elif (buffer_size < 2)
#error Buffer to small! mindestens 2 Bytes!
#endif
//##############################################################################
#endif // ifndef _USI_TWI_SLAVE_H_