Admin: Created page with "The I2C_USI library is an alternative I2C master library. It is intended to be used with processors that have an USI interface. Using the hardware is better since it will use..."

2015-06-15T21:22:07Z

Created page with "The I2C_USI library is an alternative I2C master library. It is intended to be used with processors that have an USI interface. Using the hardware is better since it will use..."

New page

The I2C_USI library is an alternative I2C master library. It is intended to be used with processors that have an USI interface.

Using the hardware is better since it will use less processor resources.

If a processor has TWI, use the TWI

If a processors has USI, use the USI

If a processor has no hardware I2C, use the default built in software routines.

 

To use the USI in master mode, use [[CONFIG USI|CONFIG USI]].

<source lang="bascomavr">

'------------------------------------------------------------------------------
' (c) 1995-2014 MCS Electronics
' USI-MASTER.bas
' USI used as TWI master demo
'------------------------------------------------------------------------------

$regfile = "attiny2313.dat"
$crystal = 8000000
$hwstack = 40
$swstack = 16
$framesize = 24
$baud = 19200

config usi = twimaster , mode = fast

dim b as byte

i2cinit

do
i2cstart
i2cwbyte &H40 'send slave WRITE address for PCF8574
i2cwbyte &B10101010 'send a pattern
i2crepstart 'repeated start

i2cwbyte &H41 'send slave READ address
i2crbyte b , ack 'read a byte
i2crbyte b , nack 'and again
i2cstop 'end transaction and free bus

waitms 100 'some delay not required only when you print
loop
</source>

<br/>{{Languages}}

[[Category:ASM Libraries and Add-Ons]]

I2C USI - Revision history

Admin: Created page with "The I2C_USI library is an alternative I2C master library. It is intended to be used with processors that have an USI interface. Using the hardware is better since it will use..."