Alcor6L/PicoLisp/i2c

This module contains functions for accessing the I2C interfaces of the Alcor6L CPU.

Only master I2C mode is implemented in eLua (and Alcor6L).

Functions

i2c-setup

Setup the I2C interface.

(i2c-setup id speed)

• id - the ID of the I2C interface.
• speed - the clock frequency of the I2C interface. It can be *i2c-fast* (400KHz), *i2c-slow* (100KHz) or a number giving the required I2C bus clock speed in Hz.

Returns:

• speed - the actual speed of the I2C interface.

i2c-start

Send a START on the specified I2C interface.

(i2c-start id)

• id - the ID of the I2C interface.

Returns: NIL.

i2c-stop

Send a STOP on the specified I2C interface.

(i2c-stop id)

• id - the ID of the I2C interface.

Returns: NIL.

i2c-address

Send an address on the I2C interface.

(i2c-address id address direction)

• id - the ID of the I2C interface.
• address - the address.
• direction - *i2c.transmitter* if the master wants to send data, or *i2c-receiver* if the master wants to receive data.

Returns:

• asked - true if the address was acknowledged by an I2C slave, false otherwise.

i2c-write

Writes data to a slave that has already acknowledged an i2c-address call.

(i2c-write id any1 [any2] ... [anyn] )

• id - the ID of the I2C interface.
• any1 - the data to send. It can be either a number between 0 and 255, a symbol or a list.
• any2 (optional) - the second data to send.
• anyn (optional) - the n-th data to send.

Returns:

• wrote - the number of bytes actually written.

i2c-read

(i2c-read id numbytes)

Reads a number of bytes from a slave that has already acknowledged an i2c-address call. It acknowledges all the bytes received except for the last one.

• id - the ID of the I2C interface.
• numbytes - the number of bytes to read.

Returns:

• data - a string with all the data read from the I2C interface.