I2C driver support for hardware abstraction layer
uint16_t value, i2cPeriphAddr, i2cRegAddr;
rt_dev_t i2c_bus;
// init
i2c_bus = i2c_getFreeDevice();
i2c_setBaudSpeed(i2c_bus, I2C_BAUD_400K);
i2c_setAddressWidth(i2c_bus, 7);
i2c_enable(i2c_bus);
// send and receive data
i2cPeriphAddr = 0x2A;
i2cRegAddr = 0x12;
value = i2c_readreg(i2c_bus, i2cPeriphAddr, i2cRegAddr, I2C_REG8 | I2C_REGADDR8);
value = 10;
i2c_writereg(i2c_bus, i2cPeriphAddr, i2cRegAddr, value, I2C_REG8 | I2C_REGADDR8);rt_dev_t i2c_getFreeDevice();Gives a free i2c bus device number
int i2c_open(rt_dev_t device);Open an i2c bus
int i2c_close(rt_dev_t device);Close an i2c bus
int i2c_enable(rt_dev_t device);Enable the specified i2c bus device
int i2c_disable(rt_dev_t device);Disable the specified i2c bus device
int i2c_setBaudSpeed(rt_dev_t device, uint32_t baudSpeed);Sets the speed of receive and transmit
uint32_t i2c_baudSpeed(rt_dev_t device);Gets the true baud speed
uint32_t i2c_effectiveBaudSpeed(rt_dev_t device);Gets the effective baud speed
int i2c_setAddressWidth(rt_dev_t device, uint8_t addressWidth);Sets the address width of slaves
uint8_t i2c_addressWidth(rt_dev_t device);Gets the address width of slaves
int i2c_start(rt_dev_t device);Sends a start condition
int i2c_restart(rt_dev_t device);Sends a restart condition
int i2c_stop(rt_dev_t device);Sends a stop condition
int i2c_idle(rt_dev_t device);Sends a idle condition
int i2c_ack(rt_dev_t device);Sends a ack condition
int i2c_nack(rt_dev_t device);Sends a nack condition
int i2c_putc(rt_dev_t device, const char data);Puts a byte
uint8_t i2c_getc(rt_dev_t device);Gets a byte
uint16_t i2c_readreg(rt_dev_t device, uint16_t address, uint16_t reg, uint8_t flags);Read a register at address 'reg' in i2c chip with address 'address'
ssize_t i2c_readregs(rt_dev_t device, uint16_t address, uint16_t reg, uint8_t regs[], size_t size, uint8_t flags);Read 'size' registers beginning at address 'reg' in i2c chip with address 'address'
int i2c_writereg(rt_dev_t device, uint16_t address, uint16_t reg, uint16_t value, uint8_t flags);Write 'value' in register at address 'reg' in i2c chip with address 'address'
int i2c_writeregs(rt_dev_t device, uint16_t address, uint16_t reg, uint8_t regs[], size_t size, uint8_t flags);Write 'regs' in registers that start at address 'reg' in i2c chip
flags parameter should be use with the following flag :
-
I2C_REG8(default) orI2C_REG16to indicate if register of the distant device have 8 or 16 bits register size (could be change for each transaction) -
I2C_REGADDR8(default) orI2C_REGADDR16to indicate the size of register address -
I2C_READ_RESTART(default) orI2C_READ_STOPSTARTto indicate if device need a restart or a stop followed by a start between read transaction (both exists)
This flag should be used with (|) pipes/logic or. It is not necessary to precise it if you use default value
Device assignation, configuration, send and read data fully functional
- review error return in high level function and i2c_getc
Header file : i2c.h
High level implementation file : i2c.c