2 cable and more pic

[mister_e]

answer yes...

here is something to start...
http://www.picbasic.co.uk/forum/showthread.php?t=1192

[SuB-ZeRo]

I think u understand me wrong i am trying to explain like the picture...
for exemple slave1 =S1
S1 will read the main line and will wait call for S1
all the pics must connect to the main line.

[ronjodu]

Have you considered CAN controllers? I just aquired some samples from Microchip to do that same thing. No progress yet however.

[SuB-ZeRo]

Yes that's right.I am trying to do that.It's not impossible imposible things re that we can't do.And i will find a solition if i find i will share.

[mister_e]

you don't need to get some CAN stuff for that. TWO WIRES only

One scheme... there's a thousands other way but.. I2C could be interesting also

1 Busy line
1 TX/RX line


Master enable the busy line
all slave listen the Master for a x timeout delay
Master message done, Master disable busy line and wait reply of a Slave
Slave enable busy line and talk to Master


That imply to switch I/Os to input and output but this work...

OR if you want to do everything more easy.... another scheme


1. TX (From master TX to all slave RX)
1. RX (From all slave TX to Master RX with diode mixer and pull down/pull up resistor depending of your serial mode (inverted or true driven))

[Ceug2005]

SuB-ZeRo.
Read more about "1 wire network ".
i think ... is possible to give a ID to S1/S2/....S10 and problem is solved.
line 1 - lets say - ground
line 2 - data.


All the rest is pure imagination.

[Melanie]

In it's simplest form, connect ONE wire between the comms pin of your choice on ALL your PICs. The Master has a LOW VALUE Resistor (say between 1K and 4K7) between it's comms pin and Vdd. All pics idle in RECEIVE (Input) mode.

MASTER sends a Transmit Request to the SLAVE of it's choice. The SLAVE will then reply accordingly. All PICs on completing communication return to idle in RECEIVE. No problems here. SLAVE addresses can be individually coded into the SLAVE software, or, more commonly, assign some pins on the PIC (in your case for ten SLAVES you will need four pins) to designate your SLAVE address. The SLAVE will read those pins at power-on and assign its own address accordingly - this approach is more sensible as then you only have to write ONE piece of code that will fit all the SLAVES.

If the SLAVE PICs are remotely located (ie in other parts of the building or in external equipment), then you will need a more sophisticated interface, as 0-5v one-wire lines will have a transmission limit. Try LOW baud rates (eg 300-1200 baud) at first. The upper limit will be determined by the pull-up Resistor and the number of PICs loading the comms line.