HSerin problems on power up

[mister_e]

If there's HSERIN/HSEROUT, you should use DEFINEs, unless you just need to write the USART registers.

INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler     RX_INT,     _GetData,   PBP,  no

You want to reset flags, unless, your program will loop in the ISR forever.

I haven't look the whole thing, but those are the really first thing that jump in my face.

[Luckyborg]

Thanks, I'll give the reset flags a try latter. I can't use defines as the baud rate needs to be user configurable in the field.

[mister_e]

Yes you can do it, you define one at the top, then you change it later on the fly by writing SPBRG, RCSTA, TXSTA. Check the datasheet for the recommended sequence.

[Luckyborg]

I finally had a chance to try out your suggestions by putting the defines at the beginning of the program and trying to reset the flag, but I have the same result of garbage in on the first transmission, then clear after that. Any other ideas would be appreciated.

David

[mister_e]

It may happen if your transmitter use SEROUT/SEROUT2/DEBUG and the pin idle state is not set before sending the first data.

Post your both code, receiver and transmitter end.

[Luckyborg]

I use a VB program not a pic as the transmitter. I can leave the program running while the pic is powered down. I give the pic a few seconds stabilization time after power up before the next transmission is sent

David

[mister_e]

Ok then, modify your VB program to send few garbage character, then a Synch String (let's say OK), and in your ISR use WAIT("OK") . See if this solve your problem.