Topic: arduino ATtiny85
(Read 1 time)
Nov 13, 2012, 10:50 pm
I am creating a small system of temperature and humidity detection using arduino in different places located several tens of meters between them.
So that the temperature sensors lose the signal after a few meters would then implement a system in such a way that the sensors communicate with arduino via a RS485 cable.
so I have to create an electronic circuit where I connect the temp sensor. an ATtiny85 which sends the read data to a SN75176 then using a cable rs485 I connect to another SN75176 installed on arduino.
My problem is that I do not know how to connect the pins of the ATtiny85 pin SN75176. Have you by any chance a wiring diagram?
My project is right? Other electronic parts are missing?
Re: arduino ATtiny85
Nov 14, 2012, 07:16 am
I use some ATtiny85-s for the same purpose, too...
But I connect them via one data cable with the central...
The central pulls it high when it wants to talk to someone...
Then it calibrates the 1-bit (e. g. 20usec low) and the 0-bit (e. g. 10usec low)...
Then it sends the address of the ATtiny85 it wants to talk to...
Then it sends the request including a parity byte...
Then the ATtiny85 starts talking by pulling down the line...
U need less cables and less hardware, but it still works...