RS232 Coms

[trisb]

HI all,

I am working on a project, where I need to communicate between 4 to 8 Pics, each pic on the board, will be given a Byte value and will only run a command if this byte value is seen first, this will be done either via a Master Microchip controller or a PC,

I plan on linking up all the boards to a common point, so I can either plug in a master controller or a PC connection.
Each board will be about a inch max away form each other.
I am trying to reduce cost as much as I can, but need it to be stable as this will be used in a industrial App.,

My Questions are:
Will I need to have a MAX232 or similar on each boards and link these to a common input connection?
or can I get away with just one MAX232 on the common input connection and then link each board to this?

any suggestions would be very much appreciated.

Thanks guys

Tristan

[Steve]

RS232 is a point-to-point protocol and can only be used to link one device to another. If you have many chips that you need to interconnect, you will need to use a different protocol.

Presuming you have a single "master" node, you can use I2C or SPI.

[trisb]

Hi Steve,

Thanks for the reply.
I did not know this at first, but now I have done a bit of research... and with your reply.
I have now changed this and I will now be using RS485.

I do have a few questions about using RS485, some of witch I have found the answers by look through the site.

however can any one recommend some software to use to for communicating with RS485 devices?
my ideal interface software would be a windows based program. but i have no clue on how to go about making such a program to control 2 and up to 12 of the driver cards I am working on.

any help would be very much appreciated.

Thanks

Tristan