1-wire emulator

[johnyman34]

I want to emulate a 1-wire device with a Pic!
Any ideia to start?

regards

Joao

[DynamoBen]

That’s pretty easy. OWIN and OWOUT are going to be the commands you use. As far as the protocol I would start with looking through datasheets on the maxim site. The protocol is generally very simple. The only problem you may have is you need a unique ID number if there are going to be other nodes on the line and you will have to create a CRC for each packet. It’s a Master/Slave arrangement so you will need a master to control these slaves you are creating.

This may be a good place to start:

http://www.maxim-ic.com/appnotes.cfm/appnote_number/126

[johnyman34]

Hi DyamoBen
First of all tank you for your kindly reply.

Do you think i can start with something like this?


loop:
owin 2,1,[value]
if value <>0 then continue
goto loop

continue:


tks in advance

[DynamoBen]

Its hard to say for sure if this will work for your application. That being said the command you have will listen to the one-wire line and recieve one byte of data.

You may want to make sure you are specifing the pin the one wire is connected to.

OWIN Pin, Mode,[ Item... ]

IE: owin PortB.2,1,[value]

[Darrel Taylor]

I hate to be the little Smurf that always runs around saying "It'll never work!", but...

It'll never work!

1-wire devices have a Master/Slave type arrangement. OWIN and OWOUT are both Master commands. OWIN will receive from a slave, but will not receive from another master.

If you want to create a slave device, you'll need to write your own routines, which will not be very easy because the timing requirements for 1-wire devices are very strict.

If you decide to write your own. Here's everything you need to know about 1-wire.
http://www.maxim-ic.com/appnotes10.cfm/ac_pk/1
<br>

[DynamoBen]

boo-hiss

I guess it can't be done.