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.