Communication between two PIC with single-wire

strsh · Joined: 16 Jul 2013 Posts: 34

Greetings.
Can you write me an example of communication between two PIC (any 8 bit) with a single wire. I looked on the internet, I tried to write code, but I did not succeed. I know there is a solution but I'm not so "strong" in programming and I ask for your help.
Thank you in advance.

ezflyr · Joined: 25 Oct 2010 Posts: 1019 Location: Tewksbury, MA

Hi,

Bi-directional communications?

A 'single wire'? A *true* single wire, or a single wire plus Gnd?

John

strsh · Joined: 16 Jul 2013 Posts: 34

For starters, one-way communication transmitter-receiver.
I have three wires 1-GND, 2 - VCC, 3 - communication.
I apologize if there are grammatical errors. I write through Google translator, but I hope it is understandable.
Thanks for your prompt response.

temtronic · Posted: Wed Apr 23, 2014 2:53 pm

Have a look in the FAQ section of the CCS C manual. They give a good example on how to do it !!!

There are other methods,but for short distances it's a very good place to begin.I'm assuming you only need a meter or so distance ?

I've done true single wire communications for 25+ years,up to 15 miles on a single wire,not fast but ultra reliable.

hth
jay

John P · Joined: 17 Sep 2003 Posts: 331

Check out Roman Black's "Blacknet" system:
http://www.romanblack.com/blacknet/blacknet.htm

temtronic · Posted: Wed Apr 23, 2014 6:49 pm

A couple decades ago Motorola had an 'addressable UART' (MC14469 ?),there's an application note about using it in 'single wire' mode.Should be easy to get a PIC to work very similarly though Black's design is very similar !

The more you read, the better choice you can make.

Best teacher though is a breadboard and time to experiment.

hth
jay

bkamen · Posted: Thu Apr 24, 2014 9:51 am

Why not use 2 wires?

Power w/data signal riding on top and GND?

Also, you could look up Dallas Semi's 1wire protocol for ideas.

-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D

Gabriel · Joined: 03 Aug 2009 Posts: 1067 Location: Panama

A while back i posted this:

http://www.ccsinfo.com/forum/viewtopic.php?t=51489

Which does a single byte, over a single wire, on any pin.

It relies on Software serial, so it has the same flaws, like not being interrupt friendly.

I was attempting to improve software serial by reducing the waiting time the PICs are stuck on the software serial routines.
I leave it to others to decide if i succeeded or not, or if this is helpful in any way.

EDIT: That "Blacknet" was a nice read!

G.
_________________
CCS PCM 5.078 & CCS PCH 5.093

temtronic · Posted: Thu Apr 24, 2014 8:00 pm

hmmm....from the OP, 2nd entry....

"For starters, one-way communication transmitter-receiver. "

We're over complicating things guys....

simple 'putc()' for the xmt..

simple 'getc() for the rcv..

should do fine.
basic 'rs232' type communications

examples are in the FAQ section of manual( I think.been a loooong day)

hth
jay

strsh · Joined: 16 Jul 2013 Posts: 34

Thanks for your answers.
You helped me with your suggestions to establish one-way communication between the two PIC with RS232 protocol. Thank you.
Greetings.