How to apply reception using P16F873A with address detection

The project need address detection when receiving the data. I read through the data sheet of the P16F87xA and knew that the 9-bit receiving mode can be set up to achieve this. But I still don't konw how to apply it in the program. Could anyone can tell me in details?Appreciate

Re: How to apply reception using P16F873A with address detec

ProjecterF said:

The project need address detection when receiving the data. I read through the data sheet of the P16F87xA and knew that the 9-bit receiving mode can be set up to achieve this. But I still don't konw how to apply it in the program. Could anyone can tell me in details?Appreciate

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What are you talking about?, RS232 or what?.

I mean recieve the data from the 75176 using the Rx pin of the pic controller.

ProjecterF said:

I mean recieve the data from the 75176 using the Rx pin of the pic controller.

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There's no address detection in hardware, you need to do it in software. The UART is designed for RS232, NOT RS485.

So could you please tell me how I can do the address detection in software. Appreciate.

ProjecterF said:

So could you please tell me how I can do the address detection in software. Appreciate.

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You first need to decide on the communication protocol you're going to use, and the size of 'packet' you will be sending.

Assuming you use a two byte packet, then the first byte will be the address, and the second the data. Simply read both bytes into two GPR's, and check if the address is correct - if not then throw both bytes away.

In practice it won't be as simple as that, you need a 100% way to detect the start of a packet, and probably checksum bytes as well?.

There may well be RS485 protocols commonly used?, I've no idea I've never used it. Bear in mind it is essentially a crude networking system, so you've got to account for collisions etc.