Serial UART and Interupts on a 16F87X

[cncmachineguy]

In your isr you check for relay =1..6. Then you GOTO a routine to turn the proper relay on. Then from there you GOTO back to loop.

Isr is never re-enabled. Plus you goto out of your isr sub routine so there is no way to get back and properly return.

That's my thoughts.

[Archangel]

Ok probably I am wrong again:
DISABLE
RECEIVE:
I think Disable should go inside this sub directory
like
RECEIVE:
DISABLE
Cause if you goto receive then do not you sail past the disable?
Also you have if then loops for condition 1:6,
where does it go if NOT 1:6?

WW6PAC

[scasale]

If it is not 1 thru 6 then it loops back to the start. I will look at this again in the AM as I start work early.
I put an ENABLE after the RESUME. Does that in itself not restart the checking for an interupt? But maybe I need a GOTO loop just after that. I noticed I missed a goto loop just after the ENABLE. Looks like it has no where to go! Maybe that is what I missed.
DO I need to set the option reg for a rising edge for the incomming serial?

Thanks,

Scott

[scasale]

I also agree that the disable goes inside, but all the code I see eaxamples of always put it just before the subroutine, so that is what I did.

[cncmachineguy]

Ok maybe a better way for me to explain is this:

Think about the ISR as a subroutine. As such it MUST be returned from. In the case of ON INTERRUPT, this is the RESUME statement. But in your case you jump past the resume with the GOTO's in the ISR. I don't know if the interrupt get re-enabled, but I don't think so because of this. You have 2 choices IMHO.

1. make all the goto's gosub's in the IF's, then change the GOTO loop in each RELAY action to return.
2 This is my favorite:

Loop:
HSEROUT stuff
IF Relay > 0 then
   If relay = 1 then outr1
   If relay = 2 then outr2
   If ....
Endif

Then in each outr routine, set relay = 0 before you goto loop.

Last thing, Don't use loop for a label. It is reserved in later releases of PBP.

[HenrikOlsson]

Hi,
I never use ON INTERRUPT so I don't know if you have to clear the interrupt flag before resuming (the USART flag clears itself when reading the RXREG but the interruptflag). Apart from that I think Bert is on it. You get to the interrupt, then you GOTO one of the Outx routines and then you END....

ENABLE/DISABLE are not normal "PBP commands" that executes at runtime. They are directives to the compiler to tell it where to start/stop inserting commands to poll the interrupt flag. In this case it doesn't matter if you put ENABLE before or after the Receive: label since ENABLE is not a command that executes at runtime.

/Henrik.

[scasale]

Ok, I made the following changes and it is not responding to any data now. It does continue to send data, just won't receive.
Also the code from the PC sets the corosponding relay back to 0 at the end of the command.
Example TX 2,1 then TX 2,0 meaning relay 2 HIGH then relay 2 LOW. Relays 3 thru 6 are latching and are unlatched when a differint relay is selected. Only relays 1 and 2 are momentary.

Intersting thing is I had this working great when connecting to a PC directly using COM Port with OUT interupts. I was using RTS/CTS but now that I am going thru a LAN to serial adapter it does not behave the same. I just recently added a RS-232 level converter that has a MAX232 of some flavor on board, so maybe I'll give the RTS/CTS deal a try again. I would love to get a handle on this interupt thing though so I can grow my PIC projects!

I also took out the wait statement, because I understand the UART can only grab 2 bytes at a time. Changed loop to MAIN.

Thanks for the info on ENABLE/DISABLE. It is for the compiler! I'll keep grinding away here.


on interrupt goto RECEIVE

MAIN:

TRANSMIT:
ADCIN 0, POTADC 'convert ADC value to a byte value:
HSEROUT [DEC POTADC,32] 'TX DATA on PORTC.6
PAUSE 300

GOTO MAIN

DISABLE
RECEIVE:
IF (RCSTA.2=1) THEN
HSERIN [RXBYTE]
else
HSERIN 500,TRANSMIT,[relay,stat] 'Serial data in on PortC.7
endif

IF relay = 1 THEN GOSUB outr1 ' Process relay#1 routine
IF relay = 2 THEN GOSUB outr2 ' Process relay#2 routine
IF relay = 3 THEN GOSUB outr3 ' Process relay#3 routine
IF relay = 4 THEN GOSUB outr4 ' Process relay#4 routine
IF relay = 5 THEN GOSUB outr5 ' Process relay#5 routine
IF relay = 6 THEN GOSUB outr6 ' Process relay#6 routine

RESUME
ENABLE
GOTO MAIN

'***************** DRIVE RELAYS ******************************************
outr1:
IF stat = 1 THEN high1
LOW CW: RETURN
high1:
HIGH CW: RETURN ' Turn on CW Relay

outr2:
IF stat = 1 THEN high2
LOW CCW: RETURN
high2:
HIGH CCW: RETURN ' Turn on CCW Relay

outr3:
IF stat = 1 THEN
HIGH ANT1: LOW ANT2: LOW ANT3: LOW ANT4
RETURN ' Turn On Relay for Antenna 1
endif

outr4:
IF stat = 1 THEN
HIGH ANT2: LOW ANT1: LOW ANT3: LOW ANT4
RETURN ' Turn On Relay for Antenna 2
endif

outr5:
IF stat = 1 THEN
HIGH ANT3: LOW ANT1: LOW ANT2: LOW ANT4
RETURN ' Turn On Relay for Antenna 3
endif

outr6:
IF stat = 1 THEN
HIGH ANT4: LOW ANT1: LOW ANT2: LOW ANT3
RETURN ' Turn On Relay for Antenna 4
endif

END