serial data ideas please

[spcw1234]

What did you end up changing?

[retepsnikrep]

Just the oscon and osctune to your values.

[retepsnikrep]

DT Interrupts?

A problem has appeared and when the routine has been runing for a random amount of time the TX side of the usart starts sending garbage causing a crash in my external equipment. I have used a scope and logic probe on the input/output and the incomming data is correct.

I'm running the 18F2620 at 32mhz and have removed all my extra code so the pic is now just running this interupt driven USART rxd & txd 9600,8,E,1

Any stupid errors spring to mind?

Bizzarely when the code is running correctly if I touch a piece of wire to the GND on my pcb the usart crashes and sends garbage or if i connect my unconnected to anything else logic analyser to just the gnd pin the usart crashes? The wire or equipment does not have to be connected to anything so perhaps is picking up some EMI but how can that be affecting the pic? Any ideas on extra capacitance to add. Is the pic flaky at 32mhz? The pic and code seems solidly reliable otherwise.

'------------------------------ General 18F2620 configuration --------------------------

#CONFIG
 __CONFIG _CONFIG1H, _OSC_INTIO67_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
 __CONFIG _CONFIG2L, _PWRT_OFF_2L & _BOREN_OFF_2L
 __CONFIG _CONFIG2H, _WDT_OFF_2H
 __CONFIG _CONFIG3H, _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_OFF_3H
 __CONFIG _CONFIG4L, _STVREN_OFF_4L & _LVP_OFF_4L & _XINST_OFF_4L & _DEBUG_OFF_4L
#ENDCONFIG

DEFINE OSC 32			'Set PicBasic Pro processor speed to 8 Mhz (Must change this if run at 32mhz mode)  
OSCCON = %01110000 		'Internal 8 mhz Osc and stable 
OSCTUNE= %11000000		'Pllen Frequency Multiplier Enabled for 8mhz Clock enables 32mhz Clock!!

CMCON  = %00000111		'Comparators Off
CVRCON = %00000000		'CvRef Powered Down 

CCP1CON= %00001100		'CCP1 Module PWM Mode
CCP2CON= %00000000		'CCP2 Module Disabled 

HLVDCON= %00000000		'HLVCON Disabled

T1CON  = %00110000		'$30 = Prescaler 1:8, TMR1 OFF
	
TRISA = %00001011 		'SET PORTA0, A1 & A3 AS INPUTS, REST AS OUTPUTS
TRISB = %00000000 		'SET PORTB AS OUTPUTS
TRISC = %11010000 		'SET PORTC AS OUTPUTS EXCEPT PORT C4 & C6,C7 
	
ADCON0 = %00000001		'SETUP ADC & ENABLE ADC MODULE on AN0
ADCON1 = %00001110		'SETUP ADC SET REFV to VDD & VSS AN0 
ADCON2 = %00100010		'SETUP ADC FOSC/32 LEFT JUSTIFY TAD 8

DEFINE LCD_DREG PORTB 		'PORTB is LCD data port
DEFINE LCD_DBIT 0 		'PORTB.0 is the data LSB
DEFINE LCD_RSREG PORTC 		'RS is connected to PORTC.0
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTC 		'EN is connected to PORTC.1
DEFINE LCD_EBIT 1
DEFINE LCD_BITS 8 		'8 lines of data are used
DEFINE LCD_LINES 4 		'It is a 4-line display
DEFINE LCD_COMMANDUS 2000 	'Use 2000uS command delay
DEFINE LCD_DATAUS 50 		'Use 50uS data delay

DEFINE ADC_BITS 8      		'Set number of bits in result
DEFINE ADC_CLOCK 3      	'Set Clock source (3 = rc)
DEFINE ADC_SAMPLEUS 50     	'Set sampling time in uS
   
DEFINE CCP1_REG PORTC 		'HPWM channel 1 pin Port C Backlight PWM Driver
DEFINE CCP1_BIT 2 		'HPWM channel 1 pin Bit 2

'Setup the hardware USART for 9600 baud

DEFINE HSER_BAUD 9600		'Set Baud rate to 9600bps
DEFINE HSER_BITS 9		'Set to 9 bit mode
DEFINE HSER_EVEN 1		'Set Even Parity
DEFINE HSER_CLROERR 1 		'Clear overflow error automatically


'Button		var PORTA.0	'Joy Button Input
HLineIn		var PORTA.1	'H Line In
HLineOut	var PORTA.2	'H Line Out
KLineIn		var PORTA.3	'K Line In
KLineOut	var PORTA.4	'K Line Out
GreenLed	var PORTA.5	'Green Led Out
Scs		    var PORTA.6	'SCS Line Out
Piezo		var PORTA.7	'Piezo Buzzer Out

Lcd0		var PORTB.0	'Parallel Lcd0
Lcd1		var PORTB.1	'Parallel Lcd1
Lcd2		var PORTB.2	'Parallel Lcd2
Lcd3		var PORTB.3	'Parallel Lcd3
Lcd4		var PORTB.4	'Parallel Lcd4
Lcd5		var PORTB.5	'Parallel Lcd5
Lcd6		var PORTB.6	'Parallel Lcd6
Lcd7		var PORTB.7 	'Parallel Lcd7

LcdRS		var PORTC.0	'Parallel LcdRS Line
LcdEN		var PORTC.1	'Parallel LcdEN Line 
LcdLight	var PORTC.2	'Parallel Lcd Backlight Control
I2CClock	var PORTC.3	'I2CClock Line
I2CData		var PORTC.4	'I2CData Line
RedLed		var PORTC.5	'Red Led Out
'Txd		var PORTC.6	'Usart Logger Txd
'Rxd		var PORTC.7	'Usart Logger Rxd


'*******************************************************************************

'Variables Constants and I/O definitions

'------------------------ Variables 16bit --------------------------------------


	
'------------------- Variables 8bit --------------------------------------------

IChkSum   var BYTE  	'MotA Line rolling Checksum Byte
AssistLevel   var byte 	'Shows level of Ima Assist
RegenLevel    var byte	'Shows level of Ima Regen
FlagBits  var BYTE	'Flag Bits Byte (0-7)  
DutyCycle var BYTE	'PWM DutyCycle for Lcd backlight [127 = 50% duty] 
Key 	  var BYTE 	'Returned Button Value (0-5) 5 = No key pressed
Gen	  var BYTE	'Gen is a General Use Byte variable (0-255)

ImaCtrl	   var BYTE	'Ima Control Byte 0-8 (0-3 = Regen) 4 = Off (5-8 = Assist) 


LCM	  VAR BYTE    	'Lcd Command Code 254

LCL       VAR BYTE    	'Lcd Control Code  Clear Lcd

L12       VAR BYTE    	'Lcd Control Code  Line 1 Column 0
L22       VAR BYTE    	'Lcd Control Code  Line 2 Column 0
L32       VAR BYTE    	'Lcd Control Code  Line 3 Column 0
L42       VAR BYTE    	'Lcd Control Code  Line 4 Column 0

L52       VAR BYTE    	'Lcd Control Code  Line 1 Column 10
L62       VAR BYTE    	'Lcd Control Code  Line 2 Column 10
L72       VAR BYTE    	'Lcd Control Code  Line 3 Column 10
L82       VAR BYTE    	'Lcd Control Code  Line 4 Column 10

'------------------- Variables 1bit --------------------------------------------


AssistBit var FlagBits.Bit1 	'Assist Bit Shows when Ima Assist in operation. 
RegenBit  var FlagBits.Bit2 	'Regen Bit Show when Ima Regen in operation. 



'------------------------------ Main Program -----------------------------------

EEPROM 1014, [254,1,128,192,148,212,138,202,158,222]	'20x4 Lcd Control Codes

'**************************************************************************************************************	

'Alias & Vars
RCIF VAR PIR1.5             	'Receive  interrupt flag (1=full , 0=empty)
TXIF VAR PIR1.4             	'Transmit interrupt flag (1=empty, 0=full)
OERR VAR RCSTA.1            	'Alias OERR (USART Overrun Error Flag)
CREN VAR RCSTA.4           	'Alias CREN (USART Continuous Receive Enable)

Ptr_in VAR BYTE             	'Pointer - next empty location in buffer
ErrFlag VAR BYTE            	'Holds error flags
ptr_in = 0                  	'Clear buffer pointer (in)

Errflag = 0                 	'Clear error flag
Char var byte			'Define Char as the data byte being sent
RCSTA.7 = 1             'Configue PortC 6 & 7 as Usart
BAUDCON.4 = 1                   'Invert USART Output for use with Transistor driver  TXCKP

'-----------------------------------------------------------------------------
INCLUDE "DT_INTS-18.bas"
INCLUDE "ReEnterPBP-18.bas"     	'Include if using PBP interrupts

ASM
INT_LIST  macro    ;IntSource,        Label,       Type,    ResetFlag?
        INT_Handler    RX_INT,      _INT_Serin,     PBP,        no
    endm
    INT_CREATE               	;Creates the interrupt processor
ENDASM

@   INT_ENABLE   RX_INT     	;Enable external (INT) interrupts
'-----------------------------------------------------------------------------

'***********************************************************************  

'Skip over the interupt handler & subroutines

	goto Start

'***********************************************************************  

'-------------------------------------
' INTERUPT HANDLER
'-------------------------------------
		
INT_Serin:                  				'Serial Interrupt routine

	IF OERR Then usart_error 			'Check for USART errors
	HSerin [Char]     				'Read USART 
	
	if Char = $B3 then             			'Start of 9 byte packet
	Ptr_In = 0                     			'Reset Ptr_In to 0
	IChkSum = 0                    			'Clear Checksum Byte
	else
	Ptr_In = Ptr_In + 1            			'Increment pointer 
    	endif 
    
    	If Ptr_In = 1 then                 		'If Byte is 1 then check if assist or regen requested
       	If AssistBit = 1 then Char = %00010000        	'Modify byte 1 for Ima Assist Control = 16 Normal 
	    if RegenBit  = 1 then Char = %00100000          'Modify byte 1 for Ima Regen  Control = 32 Normal
        endif
    	    
    	If Ptr_In = 2 then                 		'If Byte is 2 then check if assist or regen requested             
        if AssistBit = 1 then Char = AssistLevel   	'Load Char byte 2 with Ima Assist Value 0-127 = 0-100%
        if RegenBit  = 1 then Char = RegenLevel		'Load Char byte 2 with Ima Regen  Value 127-0 = 0-100%
    	endif 
        
        If Ptr_In = 5 then                 		'If Byte is 5 then check if Regen requested
        If AssistBit = 1 then Char = %00100001        	'Modify byte 5 for Ima Assist Control = 33
        if RegenBit  = 1 then Char = %00000001          'Modify byte 5 for Ima Regen Control  = 1
        endif
            
    	if Ptr_In = 8 then              		'Calculate IChkSum Byte
	IChkSum = ~ IChkSum				'NOT CheckSum
	IChkSum = IChkSum + 1				'Add 1 to CheckSum
	Char = IChkSum & $7F	 			'AND $7F
    	else
   	IChkSum = IChkSum + Char       			'Add Char to accumulated data
    	endif     
    
    	hserout [Char]                              	'Sends data     
        	
	IF RCIF = 1 Then INT_Serin 				'Check for another character while we're here
	
	Toggle RedLed  	                         	'Flash the Red Led


@ INT_RETURN           					'Return to program

USART_Error:                				'Error - USART has overrun (data too fast?)

    	errflag.0 = 1               			'Set the error flag for hardware 
	CREN = 0 					'Disable continuous receive to clear overrun flag
	CREN = 1            				'Enable continuous receive

@ INT_RETURN           					'Return to program


'**************************************************************************************************************	

'OBDII Gauge Main Program  

Start:                          			'Start of Program 
	
	ImaCtrl = 4					'Ima Control Byte = 4 (No Assist or Regen)
	Gosub SetIma					'Gosub Set Ima Routine
	
		
	Read 1014,LCM,LCL,L12,L22,L32,L42,L52,L62,L72,L82	'Load 20x4 Lcd Control Codes from EEprom adr 

	HPWM 1, 255, 500   				'Change/Start 500hz HPWM 'Set Backlight Duty 0 = Off 255 = FullOn

   	Pause 2000                              	'Pause for 2.0 seconds

	LCDOUT LCM,LCL 
	
	    	
'**************************************************************************************************************	

DispLoop:						'Main Loop goes here

	Toggle GreenLed					'Flashes Green Led
  	
'***************************** Key Functions KeyBit 0 ****************************************

'*Key Check*

	Gosub KeyPress					'Gosub KeyPress Routine 5 = No Key Pressed
	
'*Key Bit Toggle* Press

    if Key = 0 then					'If Key = 0 (Press) then 
	ImaCtrl = 4					'Ima Control Byte = 4 (No Assist or Regen)
	Gosub SetIma					'Gosub Set Ima Routine
	endif      

        
'*Assist Up / Regen Down* Button Right

	if Key = 2 then			'If Key = 2 (Right) and KeyBit = 0 then (Toggle Assist Bit)
	If ImaCtrl < 8 then ImaCtrl = ImaCtrl + 1	'Increment ImaCtrl Byte if < 8
	Gosub SetIma					'Gosub Set Ima Routine
	endif 

'* Assist Down / Regen Up* Button Left
	
	if Key = 4 then			'If Key = 4 (Left) and KeyBit = 0 then (Toggle Regen Bit)
	If ImaCtrl > 0 then ImaCtrl = ImaCtrl - 1	'Decrement ImaCtrl Byte if > 0
	Gosub SetIma					'Gosub Set Ima Routine
    	endif  

      	
'* Display Assist/Regen Status on Screen
	
	LCDOUT LCM,146					'Set Display to Line 1, Column 19        	

    	if AssistBit = 1 then LCDOUT "A",#4 - (8-ImaCtrl)	'Display Assist Data on screen if active
    	if RegenBit  = 1 then LCDOUT "R",#4 - ImaCtrl 	     	'Display Regen  Data on screen if active
	if AssistBit = 0 and RegenBit = 0 then LCDOUT 32,32	'Blank Assist/Regen data if not active    

    pause 250

	goto DispLoop					'Goto Main Loop 


'****************************** Set Ima Routine *******************************

SetIma:							'Set Ima Routine 4 levels of assist/regen 25,50,75,100%

    	If ImaCtrl = 0 then				'If ImaCtrl = 0 then set Regen 100%
	RegenLevel = 0           			'Set Regen to 100%
	RegenBit = 1					'Set Regen Bit (Regen On)
	elseif ImaCtrl = 1 then				'If ImaCtrl = 1 then set Regen 75%
	RegenLevel = 64           			'Set Regen to 75%
	RegenBit = 1					'Set Regen Bit (Regen On)
	elseif ImaCtrl = 2 then				'If ImaCtrl = 2 then set Regen 50%
	RegenLevel = 96           			'Set Regen to 50%
	RegenBit = 1					'Set Regen Bit (Regen On)
	elseif ImaCtrl = 3 then				'If ImaCtrl = 3 then set Regen 25%
	RegenLevel = 116           			'Set Regen to 25%
	RegenBit = 1					'Set Regen Bit (Regen On)

	elseif ImaCtrl = 4 then				'If ImaCtrl = 4 then set Assist & Regen to 0%
	RegenLevel = 0           			'Set Regen to 0%
	RegenBit = 0					'Clear Regen Bit (Regen Off)
	AssistLevel = 0           			'Set Assist to 0%
	AssistBit = 0					'Clear Assist Bit (Assist Off)

	elseif ImaCtrl = 5 then				'If ImaCtrl = 5 then set Assist 25%
	AssistLevel = 15           			'Set Assist to 25%
	AssistBit = 1					'Set Assist Bit (Assist On)
	elseif ImaCtrl = 6 then				'If ImaCtrl = 6 then set Assist 50%
	AssistLevel = 35           			'Set Assist to 50%
	AssistBit = 1					'Set Assist Bit (Assist On)
	elseif ImaCtrl = 7 then				'If ImaCtrl = 7 then set Assist 75%
	AssistLevel = 76           			'Set Assist to 75%
	AssistBit = 1					'Set Assist Bit (Assist On)
	elseif ImaCtrl = 8 then				'If ImaCtrl = 8 then set Assist 100%
	AssistLevel = 126           			'Set Assist to 126
	AssistBit = 1					'Set Assist Bit (Assist On)
	endif

    	return						'Return to Main Program 	


'****************************** Buttons Routine *******************************

'Check Button is pressed > Push = 0 Up = 1 Right = 2 Down = 3 Left = 4 No Key = 5 (Count1 = Press Duration)

KeyPress:                    				'Decodes Joybutton Input and returns 5 values (0,1,2,3,4) in Key 
    	
    	ADCIN 0, Gen					'Get value 0-255
	key = 5                         		'Set Default value for Key
	If Gen > 234 then return			'If No key pressed then key = 5 return
	if Gen < 235 then key = 2			'Test if button 2 pressed Right
	if Gen < 192 then key = 1			'Test if button 1 pressed Up
	if Gen < 150 then key = 4			'Test if button 4 pressed Left
	if Gen < 107 then key = 3			'Test if button 3 pressed Down
	if Gen < 64  then key = 0			'Test if button 0 pressed Press	
	
	High Piezo                             		'Sound Piezo
  	pause 75                              		'Pause for 0.075 seconds
	low Piezo                              		'Stop Piezo
	return						'Return to main program

[languer]

Sounds like there may be a HW issue. What does the simplified code looks like? Have you checked the errata on the device? There are USART flags for every silicon - but more so for the rev A's.

[retepsnikrep]

How do you know which version of silicon you have?

Does PBP 3.04 code take into account these below errata issues?

This looks suspect as I am using 9 bit HSEROUT mode with parity etc.

17. Module: EUSART
When performing back-to-back transmission in
9-bit mode (TX9D bit in the TXSTA register is
set), an ongoing transmission’s timing can be
corrupted if the TX9D bit (for the next
transmission) is not written immediately following
the setting of TXIF. This is because any
write to the TXSTA register results in a reset of
the baud rate timer which will effect any ongoing
transmission.
Work around
Load TX9D just after TXIF is set, either by polling
TXIF or by writing TX9D at the beginning of the
Interrupt Service Routine, or only write to TX9D
when a transmission is not in progress
(TRMT = 1).
Date Codes that pertain to this issue:
All engineering and production devices.

18. Module: EUSART
When performing back-to-back transmission in 9-bit
mode (TX9D bit in the TXSTA register is set), the
second byte may be corrupted if it is written into
TXREG immediately after the TMRT bit is set.
Work around
Execute a software delay, at least one half the
transmission’s bit time, after TMRT is set and prior
to writing subsequent bytes into TXREG.
Date Codes that pertain to this issue:
All engineering and production devices.

4. Module: Enhanced Universal
Synchronous Receiver
Transmitter (EUSART)
One bit has been added to the BAUDCON register
and one bit has been renamed. The added bit is
RXDTP and is in the location, BAUDCON<5>. The
renamed bit is the TXCKP bit (BAUDCON<4>),
which had been named SCKP.
The TXCKP (BAUDCON<4>) and RXDTP
(BAUDCON<5>) bits enable the Asynchronous
mode TX and RX signals to be inverted (polarity
reversed). RXDTP has no effect on the
Synchronous mode DT signal.
Register 18-3, on page 204, will be changed as
shown on page 3.
Work around
None required.
Date Codes that pertain to this issue:
All engineering and production devices

:?

[mackrackit]

I doubt it is the PIC.

With all the stuff you have going on in the ISR and the possible jumping out of the ISR is one problem. ISRs should be short and it is not a good idea to jump out of one.

Then you describe the touching of a wire to the board causes problems... That is a hardware problem you have, not the PIC. Post a schematic and someone may be able to spot the problem there.

[languer]

The MCU is HW; so yes it could have an issue. That being said, there can also be an issue with the supporting HW (i.e. around the MCU itself).

As for reading the silicon revision; look for DEVID1 on datasheet.
PicKit can read it. From Readme File of PicKit2: NOTE: silicon revision display is enabled by adding the INI file value "REVS: Y".
This link should also give you ideas on how to read it from the PIC itself:http://www.microchip.com/forums/m34318.aspx.

You say you have code which only does the UART stuff and still has the issue. What does that code looks like? I presume it shouldn't have any of the fancy interrupt, LCD, or other stuff.