diff options
Diffstat (limited to 'drivers/avr/i2c_master.c')
| -rwxr-xr-x | drivers/avr/i2c_master.c | 110 |
1 files changed, 55 insertions, 55 deletions
diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c index 4e76e2e7c..47c6f8e6c 100755 --- a/drivers/avr/i2c_master.c +++ b/drivers/avr/i2c_master.c @@ -15,15 +15,15 @@ void i2c_init(void) { TWSR = 0; /* no prescaler */ - TWBR = (uint8_t)TWBR_val; + TWBR = (uint8_t)TWBR_val; } i2c_status_t i2c_start(uint8_t address, uint16_t timeout) { - // reset TWI control register - TWCR = 0; - // transmit START condition - TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); + // reset TWI control register + TWCR = 0; + // transmit START condition + TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { @@ -32,13 +32,13 @@ i2c_status_t i2c_start(uint8_t address, uint16_t timeout) } } - // check if the start condition was successfully transmitted - if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return I2C_STATUS_ERROR; } + // check if the start condition was successfully transmitted + if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return I2C_STATUS_ERROR; } - // load slave address into data register - TWDR = address; - // start transmission of address - TWCR = (1<<TWINT) | (1<<TWEN); + // load slave address into data register + TWDR = address; + // start transmission of address + TWCR = (1<<TWINT) | (1<<TWEN); timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { @@ -47,19 +47,19 @@ i2c_status_t i2c_start(uint8_t address, uint16_t timeout) } } - // check if the device has acknowledged the READ / WRITE mode - uint8_t twst = TW_STATUS & 0xF8; - if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return I2C_STATUS_ERROR; + // check if the device has acknowledged the READ / WRITE mode + uint8_t twst = TW_STATUS & 0xF8; + if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return I2C_STATUS_ERROR; - return I2C_STATUS_SUCCESS; + return I2C_STATUS_SUCCESS; } i2c_status_t i2c_write(uint8_t data, uint16_t timeout) { - // load data into data register - TWDR = data; - // start transmission of data - TWCR = (1<<TWINT) | (1<<TWEN); + // load data into data register + TWDR = data; + // start transmission of data + TWCR = (1<<TWINT) | (1<<TWEN); uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { @@ -68,16 +68,16 @@ i2c_status_t i2c_write(uint8_t data, uint16_t timeout) } } - if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return I2C_STATUS_ERROR; } + if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return I2C_STATUS_ERROR; } - return I2C_STATUS_SUCCESS; + return I2C_STATUS_SUCCESS; } int16_t i2c_read_ack(uint16_t timeout) { - // start TWI module and acknowledge data after reception - TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA); + // start TWI module and acknowledge data after reception + TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA); uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { @@ -86,15 +86,15 @@ int16_t i2c_read_ack(uint16_t timeout) } } - // return received data from TWDR - return TWDR; + // return received data from TWDR + return TWDR; } int16_t i2c_read_nack(uint16_t timeout) { - // start receiving without acknowledging reception - TWCR = (1<<TWINT) | (1<<TWEN); + // start receiving without acknowledging reception + TWCR = (1<<TWINT) | (1<<TWEN); uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { @@ -103,39 +103,39 @@ int16_t i2c_read_nack(uint16_t timeout) } } - // return received data from TWDR - return TWDR; + // return received data from TWDR + return TWDR; } i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(address | I2C_WRITE, timeout); - if (status) return status; + if (status) return status; - for (uint16_t i = 0; i < length; i++) { - status = i2c_write(data[i], timeout); + for (uint16_t i = 0; i < length; i++) { + status = i2c_write(data[i], timeout); if (status) return status; - } + } - status = i2c_stop(timeout); + status = i2c_stop(timeout); if (status) return status; - return I2C_STATUS_SUCCESS; + return I2C_STATUS_SUCCESS; } i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(address | I2C_READ, timeout); - if (status) return status; + if (status) return status; - for (uint16_t i = 0; i < (length-1); i++) { + for (uint16_t i = 0; i < (length-1); i++) { status = i2c_read_ack(timeout); if (status >= 0) { data[i] = status; } else { return status; } - } + } status = i2c_read_nack(timeout); if (status >= 0 ) { @@ -147,47 +147,47 @@ i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16 status = i2c_stop(timeout); if (status) return status; - return I2C_STATUS_SUCCESS; + return I2C_STATUS_SUCCESS; } i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(devaddr | 0x00, timeout); - if (status) return status; + if (status) return status; - status = i2c_write(regaddr, timeout); + status = i2c_write(regaddr, timeout); if (status) return status; - for (uint16_t i = 0; i < length; i++) { + for (uint16_t i = 0; i < length; i++) { status = i2c_write(data[i], timeout); - if (status) return status; - } + if (status) return status; + } - status = i2c_stop(timeout); + status = i2c_stop(timeout); if (status) return status; - return I2C_STATUS_SUCCESS; + return I2C_STATUS_SUCCESS; } i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(devaddr, timeout); - if (status) return status; + if (status) return status; status = i2c_write(regaddr, timeout); if (status) return status; status = i2c_start(devaddr | 0x01, timeout); - if (status) return status; + if (status) return status; - for (uint16_t i = 0; i < (length-1); i++) { - status = i2c_read_ack(timeout); + for (uint16_t i = 0; i < (length-1); i++) { + status = i2c_read_ack(timeout); if (status >= 0) { data[i] = status; } else { return status; } - } + } status = i2c_read_nack(timeout); if (status >= 0 ) { @@ -199,13 +199,13 @@ i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16 status = i2c_stop(timeout); if (status) return status; - return I2C_STATUS_SUCCESS; + return I2C_STATUS_SUCCESS; } i2c_status_t i2c_stop(uint16_t timeout) { - // transmit STOP condition - TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); + // transmit STOP condition + TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); uint16_t timeout_timer = timer_read(); while(TWCR & (1<<TWSTO)) { @@ -215,4 +215,4 @@ i2c_status_t i2c_stop(uint16_t timeout) } return I2C_STATUS_SUCCESS; -} +}
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