HSERIN with/without interrupt

[Charles Linquis]

You are probably better off reading PIR1.5 in your loop. This is a flag that is set whenever the USART has a character in the buffer. It is extremely fast and doesn't waste time if no characters are waiting in the buffer. Just Put a 'IF PIR1.5 THEN...' in your main loop. If it is set, then go to HSERIN and read the characters. Put a small timeout on the HSERIN so it jumps out if ALL the expected characters aren't read.
Of course, this technique generally works best if the USART isn't going to get flooded with a continuous stream of characters.

The PIR1.5 flag gets set whenever the first character comes in, but the buffer holds up to two characters, so you actually have two character "times" to get the buffer read. The HSERIN command clears PIR1.5 when the character(s) are read.

[macinug]

Thanks for the suggestions.
Using PIR1.5 I am getting some response but it only works once in the loop.
Below is my new simplified loop for testing.
I am sending the data from the PC myself manually so there is no barrage of data for it to deal with. You say the PIR1.5 is set to 0 after reading (HSERIN?) but is the buffer also cleared or is there an instruction for that?
I thought the buffer held more than 2 characters. . .
Basically all I want to do is for the PIC to read the buffer constantly, perform one of 3 routines depending on the character "a" "b" "c", then go back to the loop and start reading for another character.
Any advice appreciated. Thanks

loop:
vbin = 0 ' reset VBIn
pause 1000
mybuzzer = 0
if pir1.5 = 1 then ' suggestion from forum, character in buffer
hserin [vbin]
sound mybuzzer,[60,10]
hserout [vbin]
Endif
goto loop