I2C Entity

See the I2C Entity for generic information.

group I2CEntity

Interface the I2C buses on BrainStem modules. The class provides a way to send read and write commands to I2C devices on the entities bus.

void i2c_read(unsigned int *id, struct Result *result, const int index, const unsigned char address, const unsigned char readLength, unsigned char *buffer)

Read from a device on this I2C bus.

The result parameter will output the following fields:

Parameters:

  • id – ID assigned through “module_createStem”

  • result – Output object containing result code.

  • index – The index of the entity in question.

  • address – The I2C address (7bit <XXXX-XXX0>) of the device to read.

  • readLength – The length of the data to read in bytes.

  • buffer – The array of bytes that will be filled with the result, upon success. This array should be larger or equivalent to aBRAINSTEM_MAXPACKETBYTES - 5

void i2c_write(unsigned int *id, struct Result *result, const int index, const unsigned char address, const unsigned char bufferLength, const unsigned char *buffer)

Write to a device on this I2C bus.

The result parameter will output the following fields:

Parameters:

  • id – ID assigned through “module_createStem”

  • result – Output object containing result code.

  • index – The index of the entity in question.

  • address – The I2C address (7bit <XXXX-XXX0>) of the device to write.

  • bufferLength – The length of the data to write in bytes.

  • buffer – The data to send to the device This array should be no larger than aBRAINSTEM_MAXPACKETBYTES - 5

void i2c_setPullup(unsigned int *id, struct Result *result, const int index, const unsigned char enable)

Set bus pull-up state. This call only works with stems that have software controlled pull-ups. Check the datasheet for more information. This parameter is saved when system.save is called.

The result parameter will output the following fields:

Parameters:

  • id – ID assigned through “module_createStem”

  • result – Output object containing result code.

  • index – The index of the entity in question.

  • enable – true enables pull-ups false disables them.

void i2c_setSpeed(unsigned int *id, struct Result *result, const int index, const unsigned char speed)

Set I2C bus speed.

This call sets the communication speed for I2C transactions through this API. Speed is an enumeration value which can take the following values: 1 - 100Khz 2 - 400Khz 3 - 1MHz

The result parameter will output the following fields:

Parameters:

  • id – ID assigned through “module_createStem”

  • result – Output object containing result code.

  • index – The index of the entity in question.

  • speed – The speed setting value.

void i2c_getSpeed(unsigned int *id, struct Result *result, const int index)

Get I2C bus speed.

This call gets the communication speed for I2C transactions through this API. Speed is an enumeration value which can take the following values: 1 - 100Khz 2 - 400Khz 3 - 1MHz

The result parameter will output the following fields:

Parameters:

  • id – ID assigned through “module_createStem”

  • result – Output object containing result code and the requested value if successful.

  • index – The index of the entity in question.