i2c - I2C access

       Generated automatically by Doxygen for bcm2835 from the source code.

bcm2835                                           Version 1.75                                            i2c(3)

       These functions let you use I2C (The Broadcom Serial Control bus with the Philips I2C bus/interface
       version 2.1 January 2000.) to interface with an external I2C device.

intbcm2835_i2c_begin(void)[extern]
       Start I2C operations. Forces RPi I2C pins P1-03 (SDA) and P1-05 (SCL) to alternate function ALT0, which
       enables those pins for I2C interface. You should call bcm2835_i2c_end() when all I2C functions are
       complete to return the pins to their default functions

       Returns
           1 if successful, 0 otherwise (perhaps because you are not running as root)

       Seealsobcm2835_i2c_end()voidbcm2835_i2c_end(void)[extern]
       End I2C operations. I2C pins P1-03 (SDA) and P1-05 (SCL) are returned to their default INPUT behaviour.

   uint8_tbcm2835_i2c_read(char*buf,uint32_tlen)[extern]
       Transfers any number of bytes from the currently selected I2C slave. (as previously set by

       Seealsobcm2835_i2c_setSlaveAddress)

       Parametersbuf Buffer of bytes to receive.
           len Number of bytes in the buf buffer, and the number of bytes to received.

       Returns
           reason see bcm2835I2CReasonCodesuint8_tbcm2835_i2c_read_register_rs(char*regaddr,char*buf,uint32_tlen)[extern]
       Allows reading from I2C slaves that require a repeated start (without any prior stop) to read after the
       required slave register has been set. For example, the popular MPL3115A2 pressure and temperature sensor.
       Note that your device must support or require this mode. If your device does not require this mode then
       the standard combined:

       Seealsobcm2835_i2c_writebcm2835_i2c_read are a better choice. Will read from the slave previously set by

           bcm2835_i2c_setSlaveAddressParametersregaddr Buffer containing the slave register you wish to read from.
           buf Buffer of bytes to receive.
           len Number of bytes in the buf buffer, and the number of bytes to received.

       Returns
           reason see bcm2835I2CReasonCodesvoidbcm2835_i2c_set_baudrate(uint32_tbaudrate)[extern]
       Sets the I2C clock divider by converting the baudrate parameter to the equivalent I2C clock divider. (
       see

       Seealsobcm2835_i2c_setClockDivider) For the I2C standard 100khz you would set baudrate to 100000 The use of
           baudrate corresponds to its use in the I2C kernel device driver. (Of course, bcm2835 has nothing to
           do with the kernel driver)

   voidbcm2835_i2c_setClockDivider(uint16_tdivider)[extern]
       Sets the I2C clock divider and therefore the I2C clock speed.

       Parametersdivider The desired I2C clock divider, one of BCM2835_I2C_CLOCK_DIVIDER_*, see bcm2835I2CClockDividervoidbcm2835_i2c_setSlaveAddress(uint8_taddr)[extern]
       Sets the I2C slave address.

       Parametersaddr The I2C slave address.

   uint8_tbcm2835_i2c_write(constchar*buf,uint32_tlen)[extern]
       Transfers any number of bytes to the currently selected I2C slave. (as previously set by

       Seealsobcm2835_i2c_setSlaveAddress)

       Parametersbuf Buffer of bytes to send.
           len Number of bytes in the buf buffer, and the number of bytes to send.

       Returns
           reason see bcm2835I2CReasonCodesuint8_tbcm2835_i2c_write_read_rs(char*cmds,uint32_tcmds_len,char*buf,uint32_tbuf_len)[extern]
       Allows sending an arbitrary number of bytes to I2C slaves before issuing a repeated start (with no prior
       stop) and reading a response. Necessary for devices that require such behavior, such as the MLX90620.
       Will write to and read from the slave previously set by

       Seealsobcm2835_i2c_setSlaveAddressParameterscmds Buffer containing the bytes to send before the repeated start condition.
           cmds_len Number of bytes to send from cmds buffer
           buf Buffer of bytes to receive.
           buf_len Number of bytes to receive in the buf buffer.

       Returns
           reason see bcm2835I2CReasonCodes

       i2c - I2C access

Functions
       int bcm2835_i2c_begin (void)
       void bcm2835_i2c_end (void)
       void bcm2835_i2c_setSlaveAddress (uint8_t addr)
       void bcm2835_i2c_setClockDivider (uint16_t divider)
       void bcm2835_i2c_set_baudrate (uint32_t baudrate)
       uint8_t bcm2835_i2c_write (const char *buf, uint32_t len)
       uint8_t bcm2835_i2c_read (char *buf, uint32_t len)
       uint8_t bcm2835_i2c_read_register_rs (char *regaddr, char *buf, uint32_t len)
       uint8_t bcm2835_i2c_write_read_rs (char *cmds, uint32_t cmds_len, char *buf, uint32_t buf_len)