Hi boroko,
You're throwing away perfectly good data with that.Code:Getbytes: While RCIF = 1 ' clear the buffer HSERIN 100,error,[Serialdata] ' Get serial led2count = led2count + 1 ' Incr heartbeat Wend
You need to process everything that comes in, even if it's not for this chips address.
And you don't need a Timeout in the HSERIN, because it's guaranteed to have a byte in the USART if it triggers an interrupt.
Well, I wrote this last night. I thought I'd get a chance to test/debug it. But today I've got 5 people coming at me from 4 different directions.
Makes me wonder what those 2 are doing together.
Hopefully, what I was trying to say will show through, if it doesn't work.
Basically it's, make the Handler as fast as possible. Get in, do your thing, and get out.
No PAUSES, no HSEROUTS, nothing that will keep it from leaving the interrupt as fast as possible.
Anything that needs to take time, should be done in the main loop. Where it can be interrupted again..
Flags are used to trigger those "Main Loop" processes.
Hope it gives some direction ...
If nothing else, note the changes to the Getbytes: handler.
Code:'::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: 'Based on Hserin with Darrel Taylor's Instant Interrupts '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ' Program to echo incoming serial data. ' RX SYNC byte, if good: ADDRESS byte, if good: COMMAND ' MPASM, LabX-1 , PBP2.47, Using PIC 16F877A @ 4mHz, 9600 Baud ' Using Hardware USART and MAX232 to MCS Serial Communicator on PC DEFINE OSC 4 DEFINE HSER_RCSTA 90h ' enable serial port, define HSER_TXSTA 24h ' enable transmit, define HSER_BAUD 9600 ' set baudrate to 9600 DEFINE HSER_CLOERR 1 ' automatic clear overrun error TRISD = $00000000 'D to outputs for the LEDs TRISC = %10000000 ' PORTC.7 is the RX input, PORTC.6 is the TX output ADCON1 = %00001111 'Set up ADCON1 register no matter what yr doing!!! '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: INCLUDE "DT_INTS-14.bas" ' Base Interrupt System INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ' Variable definition '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: led0 var PORTD.0 led1 var PORTD.1 led2 var PORTD.2 led7 var PORTD.7 ERROR_LED VAR led7 ' rename the LED's LATE_LED VAR led2 HEART_LED VAR led0 LEDonDELAY CON 4 CmdBuf var byte 'command for the pwm or acknowledge SerialData var byte ' ERRORtime var byte LATEtime var byte HEARTtime VAR BYTE state VAR BYTE Sync VAR state.0 ' Sync byte rcvd ForMe VAR state.1 ' Packet is for this device CmdRcvd VAR state.2 ' Command has been rcvd ERROR VAR state.3 ' Sync rcvd out of order LATE VAR state.4 ' command rcvd before last one was processed SyncByte CON "U" ID CON "A" state = 0 '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ASM INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler RX_INT, _Getbytes, PBP, no INT_Handler TMR0_INT, _TMR0handler, PBP, YES endm INT_CREATE ; Creates the interrupt processor ENDASM @ INT_ENABLE RX_INT ; enable RX_INT interrupts @ INT_ENABLE TMR0_INT ; enable TMR0_INT interrupts 65.5ms '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: hserout ["start"] 'splash screen to verify comm HSEROUT [13,10] ' CR to start new line on terminal program Mainloop: IF CmdRcvd THEN GOSUB ProcessCMD ' Process any incomming data IF ERROR THEN ' if there's been an Error HIGH ERROR_LED ' Turn ON ERROR LED ERROR = 0 ' reset the error flag ERRORtime = LEDonDELAY ' start countdown till LED-OFF HSEROUT ["Error",13,10] ENDIF IF LATE THEN ' if command took too long HIGH LATE_LED ' Turn ON LATE LED LATE = 0 ' reset the LATE flag LATEtime = LEDonDELAY ' start countdown till LED-OFF HSEROUT ["Late",13,10] ENDIF GOTO Mainloop '*********** Process received command ************************************** ProcessCMD: hserout ["Cmd: ",CmdBuf, " [", _ ' send Command and CR/LF DEC CmdBuf,"]",13,10] CmdRcvd = 0 ' indicate CMD has been processed RETURN '*********** 'ISR for TMR0_INT interrupt *********************************** TMR0handler: IF ERRORtime > 0 THEN ' if the Error LED is ON ERRORtime = ERRORtime - 1 ' decrement the count IF ERRORtime = 0 THEN ' when it reaches 0 LOW ERROR_LED ' turn the Error LED OFF ENDIF ENDIF IF LATEtime > 0 THEN ' if the LATE LED is ON LATEtime = LATEtime - 1 ' decrement the count IF LATEtime = 0 THEN ' when it reaches 0 LOW LATE_LED ' turn the LATE LED OFF ENDIF ENDIF HEARTtime = HEARTtime + 1 ' Toggle heartbeat ~.5sec IF HEARTtime = 7 THEN HEARTtime = 0 TOGGLE HEART_LED ENDIF @ INT_RETURN '*********** 'ISR for RX_INT interrupt ************************************* Getbytes: HSERIN [Serialdata] ' Get the serial data IF Serialdata = SyncByte THEN ' if it's a Sync byte, IF Sync THEN ERROR = 1 ' last command was corrupted Sync = 1 ' indicate Sync was rcvd ForMe = 0 ' ID has not been rcvd ELSE IF Sync THEN IF !ForME THEN ' if we haven't rcvd the ID IF Serialdata = ID THEN ' and this byte matches the ID ForMe = 1 ' indicate ID rcvd ELSE Sync = 0 ' Not my packet ForMe = 0 ' reset receive state ENDIF ' and wait for next Sync ELSE CmdBuf = serialdata ' store the command IF CmdRcvd THEN LATE = 1 ' last command not finished CmdRcvd = 1 ' indicate a command was rcvd Sync = 0 ' reset receive state ForMe = 0 ENDIF ENDIF ENDIF @ INT_RETURN
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