W dniu 2014-03-26 17:07, Akond ze skwak pisze:
> Czy da się zrobić na ATtiny13 master I2C w prostym układzie : Czujnik
> ->i2c->procesor->sygnalizator (beeper).

Patrz u źródeł.
http://www.atmel.com/devices/ATTINY13A.aspx?tab=docu
ments

Atmel AVR156: TWI Master Bit Bang Driver
(file size: 126KB, 4 pages, revision A, updated: 07/2012)

This application note describes a Two-wire Interface (TWI) master
implementation, in the form of a full-featured driver. Many chips
feature a hardware TWI module; others have Universal Serial Interface
(USI), which can be used in TWI mode. This application note discusses
the TWI master driver for devices without any of these hardware modules.
This driver provides interfaces to read/write to a TWI slave.

TWI to Atmelowska nazwa I2C

Ja, o ile pamiętam, lata temu używałem I2C Master autorstwa Petera
Fleury'ego
http://homepage.hispeed.ch/peterfleury/avr-software.
html

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Michał