Revision as of 20:55, 17 January 2017

Action

Initializes the SCL and SDA pins.

Syntax

I2CINIT

I2CINIT #const

Remarks

By default the SCL and SDA pins are in the right state when you reset the chip. Both the PORT and the DDR bits are set to 0 in that case.

When you need to change the DDR and/or PORT bits you can use I2CINIT to bring the pins in the proper state again.

For the XMEGA which has multiple TWI interfaces you can use a channel to specify the TWI interface otherwise the default TWIC will be used.

For normal AVR processors with multiple TWI interfaces you can specify the interface : TWI or TWI1.

When no parameter is provided, the first default TWI will be selected.

ASM

The I2C routines are located in i2c.lib. _i2c_init is called.

See also

I2CSEND , I2CSTART , I2CSTOP , I2CRBYTE , I2CWBYTE , I2C TWI Library for using TWI

Example

Config Sda = Portb.5
Config Scl = Portb.7
I2cinit
 
Dim X As Byte , Slave As Byte
X = 0 'reset variable
Slave = &H40 'slave address of a PCF 8574 I/O IC
I2creceive Slave , X 'get the value
Print X 'print it

Example XMEGA

Open "twic" For Binary As #4 ' or use TWID,TWIE oR TWIF
Config TwiC = 100000 'CONFIG TWI will ENABLE the TWI master interface
I2cinit #4