unsigned char i2c_inbyte(void) { unsigned char aBitByte = 0; int i; /* Switch off I2C to get bit */ i2c_disable(); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/2); /* Get bit */ aBitByte |= i2c_getbit(); /* Enable I2C */ i2c_enable(); i2c_delay(CLOCK_LOW_TIME/2); for (i = 1; i < 8; i++) { aBitByte <<= 1; /* Clock pulse */ i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_LOW_TIME); /* Switch off I2C to get bit */ i2c_disable(); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/2); /* Get bit */ aBitByte |= i2c_getbit(); /* Enable I2C */ i2c_enable(); i2c_delay(CLOCK_LOW_TIME/2); } i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); /* * we leave the clock low, getbyte is usually followed * by sendack/nack, they assume the clock to be low */ i2c_clk(I2C_CLOCK_LOW); return aBitByte; }
// Send a byte to the I2C bus and return the ack sequence from slave int i2c_outbyte(unsigned char x) { int i; int ack; i2c_clk(0); for (i=0;i<8;i++) { if (x & 0x80) i2c_data(1); else i2c_data(0); i2c_clk(1); udelay(5); i2c_clk(0); udelay(5); x <<= 1; } i2c_data(0); i2c_dir_in(); i2c_clk(1); ack=i2c_getbit(); i2c_clk(0); i2c_dir_out(); if (ack==0) return 1; else return 0; }
// Read a byte from I2C bus and send the ack sequence unsigned char i2c_inbyte(int ack) { unsigned char value = 0; int bitvalue; int i; // Read data byte i2c_dir_in(); for (i=0;i<8;i++) { i2c_clk(1); udelay(5); bitvalue = i2c_getbit(); value |= bitvalue; if (i<7) value <<= 1; i2c_clk(0); udelay(5); } // Send Ack if(ack){ i2c_dir_out(); i2c_data(0); i2c_clk(1); udelay(5); i2c_clk(0); } udelay(200); return value; }
/*#--------------------------------------------------------------------------- *# *# FUNCTION NAME: I2C::sendAck *# *# DESCRIPTION : Send ACK on received data *# *#--------------------------------------------------------------------------*/ void i2c_sendack(void) { /* * enable output */ i2c_delay(CLOCK_LOW_TIME); i2c_dir_out(); /* * set ack pulse high */ i2c_data(I2C_DATA_LOW); /* * generate clock pulse */ i2c_delay(CLOCK_HIGH_TIME/6); i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_LOW_TIME/6); /* * reset data out */ i2c_data(I2C_DATA_HIGH); i2c_delay(CLOCK_LOW_TIME); i2c_dir_in(); }
void i2c_outbyte(unsigned char x) { int i; i2c_dir_out(); for (i = 0; i < 8; i++) { if (x & 0x80) { i2c_data(I2C_DATA_HIGH); } else { i2c_data(I2C_DATA_LOW); } i2c_delay(CLOCK_LOW_TIME/2); i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_LOW_TIME/2); x <<= 1; } i2c_data(I2C_DATA_LOW); i2c_delay(CLOCK_LOW_TIME/2); /* * enable input */ i2c_dir_in(); }
unsigned char i2c_inbyte(void) { unsigned char aBitByte = 0; int i; i2c_disable(); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/2); aBitByte |= i2c_getbit(); i2c_enable(); i2c_delay(CLOCK_LOW_TIME/2); for (i = 1; i < 8; i++) { aBitByte <<= 1; i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_LOW_TIME); i2c_disable(); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/2); aBitByte |= i2c_getbit(); i2c_enable(); i2c_delay(CLOCK_LOW_TIME/2); } i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); return aBitByte; }
unsigned char i2c_inbyte(void) { unsigned char aBitByte = 0; int i; /* Switch off I2C to get bit */ i2c_disable(); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/2); /* Get bit */ aBitByte |= i2c_getbit(); /* Enable I2C */ i2c_enable(); i2c_delay(CLOCK_LOW_TIME/2); for (i = 1; i < 8; i++) { aBitByte <<= 1; /* Clock pulse */ i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_LOW_TIME); /* Switch off I2C to get bit */ i2c_disable(); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/2); /* Get bit */ aBitByte |= i2c_getbit(); /* Enable I2C */ i2c_enable(); i2c_delay(CLOCK_LOW_TIME/2); } i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); return aBitByte; }
int i2c_getack(void) { int ack = 1; i2c_dir_out(); i2c_data(I2C_DATA_HIGH); i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/4); i2c_clk(I2C_CLOCK_HIGH); #if 0 i2c_clk(1); i2c_data(1); i2c_data(1); i2c_disable(); i2c_dir_in(); #endif i2c_delay(CLOCK_HIGH_TIME/2); if (i2c_getbit()) ack = 0; i2c_delay(CLOCK_HIGH_TIME/2); if (!ack) { if (!i2c_getbit()) ack = 1; i2c_delay(CLOCK_HIGH_TIME/2); } #if 0 i2c_data(I2C_DATA_LOW); i2c_enable(); i2c_dir_out(); #endif i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_HIGH_TIME/4); i2c_dir_out(); i2c_data(I2C_DATA_HIGH); i2c_delay(CLOCK_LOW_TIME/2); return ack; }
void i2c_sendnack(void) { i2c_delay(CLOCK_LOW_TIME); i2c_dir_out(); i2c_data(I2C_DATA_HIGH); i2c_delay(CLOCK_HIGH_TIME/6); i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_LOW_TIME); i2c_dir_in(); }
void i2c_stop(void) { i2c_dir_out(); i2c_clk(I2C_CLOCK_LOW); i2c_data(I2C_DATA_LOW); i2c_delay(CLOCK_LOW_TIME*2); i2c_clk(I2C_CLOCK_HIGH); i2c_delay(CLOCK_HIGH_TIME*2); i2c_data(I2C_DATA_HIGH); i2c_delay(STOP_CONDITION_HOLD_TIME); i2c_dir_in(); }
int i2c_getack(void) { int ack = 1; /* * enable output */ i2c_dir_out(); /* * Release data bus by setting * data high */ i2c_data(I2C_DATA_HIGH); /* * enable input */ i2c_dir_in(); i2c_delay(CLOCK_HIGH_TIME/4); /* * generate ACK clock pulse */ i2c_clk(I2C_CLOCK_HIGH); /* * Use PORT PB instead of I2C * for input. (I2C not working) */ i2c_clk(1); i2c_data(1); /* * switch off I2C */ i2c_data(1); i2c_disable(); i2c_dir_in(); /* * now wait for ack */ i2c_delay(CLOCK_HIGH_TIME/2); /* * check for ack */ if(i2c_getbit()) ack = 0; i2c_delay(CLOCK_HIGH_TIME/2); if(!ack){ if(!i2c_getbit()) /* receiver pulld SDA low */ ack = 1; i2c_delay(CLOCK_HIGH_TIME/2); } /* * our clock is high now, make sure data is low * before we enable our output. If we keep data high * and enable output, we would generate a stop condition. */ i2c_data(I2C_DATA_LOW); /* * end clock pulse */ i2c_enable(); i2c_dir_out(); i2c_clk(I2C_CLOCK_LOW); i2c_delay(CLOCK_HIGH_TIME/4); /* * enable output */ i2c_dir_out(); /* * remove ACK clock pulse */ i2c_data(I2C_DATA_HIGH); i2c_delay(CLOCK_LOW_TIME/2); return ack; }
unsigned char i2c_inbyte(void) { unsigned char aBitByte = 0; int i; int iaa; /* * enable output */ i2c_dir_out(); /* * Release data bus by setting * data high */ i2c_data(I2C_DATA_HIGH); /* * enable input */ i2c_dir_in(); /* * Use PORT PB instead of I2C * for input. (I2C not working) */ i2c_clk(1); i2c_data(1); /* * get bits */ for (i = 0; i < 8; i++) { i2c_delay(CLOCK_LOW_TIME/2); /* * low clock period */ i2c_clk(I2C_CLOCK_HIGH); /* * switch off I2C */ i2c_data(1); i2c_disable(); i2c_dir_in(); /* * wait before getting bit */ i2c_delay(CLOCK_HIGH_TIME/2); aBitByte = (aBitByte << 1); iaa = i2c_getbit(); aBitByte = aBitByte | iaa ; /* * wait */ i2c_delay(CLOCK_HIGH_TIME/2); /* * end clock puls */ i2c_enable(); i2c_dir_out(); i2c_clk(I2C_CLOCK_LOW); /* * low clock period */ i2c_delay(CLOCK_LOW_TIME/2); } i2c_dir_out(); return aBitByte; }