Any Simple ASM interupt code examples out there?

[sougata]

Hi,

As far as I understood that you need to monitor the serial input lines for your system to get "READY" as your qualifier. You can always do the qualifier checking manually. Looking for a "R", if found then "E" if not then again "R" and so on. Thus you (your PIC) would not be sitting inside the receive subroutine. Also the b1 variable used in your code is a BIT variable. I have no idea how a bit variable is treated in the serin ?? Also your pseudo code for the interrupt makes no sense. I thought "time" was a label but your code increments it
Please give me a little more detail on the receiver module, a datasheet pointer perhaps and exactly what you are trying to achieve in plain english. 16F676 does not have a hardware USART. Using it saves you the headache of polling the serial pin quite often so that you don't miss a bit. But you need to use USART interrupt then.

[George]

Hi,

As far as I understood that you need to monitor the serial input lines for your system to get "READY" as your qualifier. You can always do the qualifier checking manually. Looking for a "R", if found then "E" if not then again "R" and so on. Thus you (your PIC) would not be sitting inside the receive subroutine. Also the b1 variable used in your code is a BIT variable. I have no idea how a bit variable is treated in the serin ?? Also your pseudo code for the interrupt makes no sense. I thought "time" was a label but your code increments it
Please give me a little more detail on the receiver module, a datasheet pointer perhaps and exactly what you are trying to achieve in plain english. 16F676 does not have a hardware USART. Using it saves you the headache of polling the serial pin quite often so that you don't miss a bit. But you need to use USART interrupt then.

How would I do the manual looking for "R", "E"... and so forth? Sorry about my pseudo code, I did it in a hurry, the lower time should read "timer" or something equiv.

The receiver module is a linx RXM LR-418 and a link to data sheets is here: http://www.linxtechnologies.com/inde...gory=lr_series

I'll I'm trying to do is not get the program stuck in the SERIN command when it's hearing radio static. even a timeout of 1ms hardly manages to break out of the command - very randomly and intermittantly. Am wanting to increment timer, I'll try using the TMR in the PIC for the 1st time on this project, but really need it to reliably be able to come out of the SERIN so I can switch other things - it will very seldom see a radio transmission - but when it does I need to capture it. Thanks for yr input so far

A BIT variable seems to work ok in serin - well I haven't had any trouble with it, and it's always responded reliably.

[sougata]

Hi,

As you mentioned most of the time your radio receiver would be idle (receiving nothing). Your intention is to get out of the serial in routine when you are getting "junk" due to the random switching of the receiver output. The code I posted can just do that for you. The SERIN can jump to a label when nothing is received in the input (the input pin remains idle). So most of the time you will get "characters" due to the receiver throtlling around the noise floor. Just validate your character manually and reset your timer_counter if it is something you expect. Say you are expecting a "R". Get the character from serin first to a byte variable then check if the byte="R" and increment another pointer to check for an "E" next. If not you can let your timer_counter roll. Also you can use a 5 byte FIFO buffer to make things easy. In the FIFO you will always have the last 5 bytes received and validation becomes easier.

You can also use the RSSI as per the datasheet to guide your PIC when to grab a data. It releives you of the software headache.

Give the receiver side code or whatever you are transmitting. I shall try to find some time to give you an example