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PIO hinzugefügt

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This commit is contained in:
Tristan Krause 2019-03-25 09:57:38 +01:00
parent 99c282566f
commit 419e37eeae
14 changed files with 954 additions and 75 deletions
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78
pio/i2c/impl0.h Normal file
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/***
* impl0.h
* This file is part of the PIO library.
* For license information see "pio.h" in the super parent directory.
*/
#if !defined(PIOLIB) || PIOLIB < 100
#error This file should be included directly. Use "pio.h" instead.
#endif
#ifndef F_CPU
#error F_CPU not defined!
#endif
#ifndef F_I2C
#ifndef PIO_DISABLE_I2C
#warning F_I2C not defined, I2C disabled.
#endif
#else
#include <stdlib.h>
// AVR TWI master transmitter status codes
#define TWS_START 0x08
#define TWS_REPEATED_START 0x10
#define TWS_ADDR_ACK 0x18
#define TWS_ADDR_NOT_ACK 0x20
#define TWS_DATA_ACK 0x28
#define TWS_DATA_NOT_ACK 0x30
#define TWS_ARB_LOST 0x38
// functions
void i2cInit(void);
void i2cBeginTransmission(uint8_t);
void i2cSend(uint8_t);
void i2cEndTransmission(void);
// error function pointer
void (*i2cError)(void) = NULL;
void i2cInit() {
// i2c clock speed, see SCL frequency formula in datasheet
uint16_t sp = F_CPU / F_I2C - 16;
uint16_t bp = sp;
while(sp > 510) {
TWSR++;
sp /= 4;
}
TWBR = bp / (1<<(2*(TWSR & 0x03)+1));
}
void i2cBeginTransmission(uint8_t addr) {
TWCR = _BV(TWEN) | _BV(TWINT) | _BV(TWSTA);
while (!(TWCR & _BV(TWINT)));
if((TWSR & 0xF8) != TWS_START)
i2cError();
TWDR = (addr & 0xFE) << 1;
TWCR = _BV(TWEN) | _BV(TWINT);
while (!(TWCR & _BV(TWINT)));
if((TWSR & 0xF8) != TWS_ADDR_ACK)
i2cError();
}
void i2cSend(uint8_t b) {
TWDR = b;
TWCR = _BV(TWEN) | _BV(TWINT);
while (!(TWCR & _BV(TWINT)));
if((TWSR & 0xF8) != TWS_DATA_ACK)
i2cError();
}
void i2cEndTransmission() {
TWCR = _BV(TWEN) | _BV(TWINT) | _BV(TWSTO);
while (TWCR & _BV(TWSTO));
}
#endif