I2C

See the I2C Entity for generic information.

class brainstem.entity.I2C(module, index)[source]

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.

getSpeed()[source]

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

Returns:

Object containing error code and returned value on success.
errorunsigned byte

An error result from the list of defined error codes

valueunsigned char

The speed setting value.

Return type:

brainstem.result.Result

read(address, read_length)[source]

Read from a device on this I2C bus.

Parameters:

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

  • read_length (unsigned char) – The length of the data to read in bytes.

Returns:

Object containing error code and returned value on success.
errorunsigned byte

An error result from the list of defined error codes

valuelist(unsigned char)

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

Return type:

brainstem.result.Result

setPullup(enable)[source]

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.

Parameters:

enable (bool) – true enables pull-ups false disables them.

Returns:

An error result from the list of defined error codes in brainstem.result.Result

Return type:

unsigned byte

setSpeed(speed)[source]

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

Parameters:

speed (unsigned char) – The speed setting value.

Returns:

An error result from the list of defined error codes in brainstem.result.Result

Return type:

unsigned byte

write(address, buffer)[source]

Write to a device on this I2C bus.

Parameters:

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

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

Returns:

An error result from the list of defined error codes in brainstem.result.Result

Return type:

unsigned byte