$FORCESOFTI2C

Action

The $forcesofti2c directive force the ATXMEGA to use software I2C/TWI Library instead of the hardware I2C registers of ATXMEGA.

 

 

Syntax

$forcesofti2c 

 

 

Remarks

ATXMEGA have usually enough I2C interfaces with fixed SDA and SCL pins but if you want to use other pins as SDA/SCL you can use this directive.

Required Library: $lib "i2c.lbx"  

 

You can not combine the soft mode with the hardware TWI. Thus when using $forcesofti2c, you can not add an additional TWI channel.

 

 

$forcesofti2c                        ' with this the software I2C/TWI commands are used when inlcuding i2c.lbx
$lib "i2c.lbx"               ' override the normal xmega i2c lib
 
 

Then you need to configure the SDA and SCL Pin and initialize the pins:

 

Config Scl = Port0 .1            ' Pin to use as SCL (The hardware pin is Pinb.1)
Config Sda = Port0 .0         ' Pin to use as SDA (The hardware pin is Pinb.0)
I2cinit                                                     ' Bring the Pin's in the proper state
 

 

 

 

See also

Using the I2C protocol

 

 

 

Example

' Using ATXMEGA with software I2C routines to use also pins which are no hardware SDA/SCL pins
' Needed Library: $lib "i2c.lbx"
' The $forcesofti2c directive force the ATXMEGA to use software I2c/TWI Library
 
' The hardware for this example is XMEGA-A3BU XPlained board from Atmel
' Don't forget the pull-ups on SDA/SCL pin !
' Bascom Version 2.0.7.6 or higher needed
 
$regfile = "XM256A3BUDEF.DAT"
$crystal = 32000000 '32MHz
$hwstack = 64
$swstack = 40
$framesize = 80
 
$forcesofti2c ' with this the software I2C/TWI commands are used when inlcuding i2c.lbx
$lib "i2c.lbx" ' override the normal xmega i2c lib
 
Config Osc = Enabled , 32mhzosc = Enabled
Config Sysclock = 32mhz , Prescalea = 1 , Prescalebc = 1_1
 
Config Portr.0 = Output
Led0 Alias Portr.0 'LED 0 (XMEGA-A3BU XPlained board from Atmel )
 
Config Portr.1 = Output
Led1 Alias Portr.1 'LED 1 (XMEGA-A3BU XPlained board from Atmel )
 
Dim B As Byte
 
'We use here Virtual port 0
Config Vport0 = B ' 'map portB to virtual port0
Config Scl = Port0 .1 ' Pin to use as SCL (The hardware pin is Pinb.1)
Config Sda = Port0 .0 ' Pin to use as SDA (The hardware pin is Pinb.0)
I2cinit ' Bring the Pin's in the proper state
 
 
Do
 
Waitms 500
Set Led1
Reset Led0
Waitms 500
Reset Led1
Set Led0
 
Incr B
 
I2cstart
I2cwbyte &H24 ' address of I2C Slave
I2cwbyte B ' databyte to send to slave
I2cstop
 
Loop
 
End 'end program

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