HSEROUT Newbie question/problem

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- 10th July 2006, 14:05
Mark Scotford

HSEROUT Newbie question/problem

I am trying to use serial comms to a PC for the first time. I am using a known good PCB from another project which has a MAX 232 chip for the RS232 I/O. The processor is a 17C756A running at 10Mhz and I am using the Serial communicator in Micro Code Studio + to see what coming out of the port. I am trying to use 2400 Baud 8N1 (which serial communicator is set up to) for no other reason than it was the first one I thought of, but I have tried others. Basically the project is a Temperature Data Logger, which will have 8 inputs and as each sensor is read in turn, squirts the value read out of the Logger to a PC, most probably running Excel. I have used ADCIN before on another project and I know I can get that to work (if its wrong in the example shown, don't worry about that I will sort it later) my problem now is to get the value stored in variable B3, out of the serial port and into my PC, at the moment, serial communicator shows characters coming out, but they are garbage and some of the time the characters change. I have forced B3 to a known value for testing purposes, so B3 should be reading as 123. I have calculated the SPBRG value from the Microchip Data Sheet AN774 as being (10000000 / (64 x 2400 =153600) -1 =64.104166. There is no High Speed option on the PIC17C756A according to the data sheet, so BRGH = 0. Incidentaly the LCD display is working fine.

Here is a listing from what I have so far:-

'FW1-0DLV1-0 09/07/2K6
'Was MCV2-2FW1-2

'A4 P43 =RS232 RX-1 Input
'A5 P42 =RS232 TX-1 Output
'B0 P59 ="Serial" LED Output
'B1 P58 ="Coin" LED Output
'B2 P54 ="Error" LED Output
'B7 P48 =Beeper Output
'D0 P11 =Display D0 Output
'D1 P10 =Display D1 Output
'D2 P9 =Display D2 Output
'D3 P8 =Display D3 Output
'D4 P4 =Display D4 Output
'D5 P6 =Display D5 Output
'D6 P5 =Display D6 Output
'D7 P4 =Display D7 Output
'E0 P12 =Display RS Output
'E1 P13 =Display R/W Output
'E2 P14 =Display E Output
'F0 P28 =AN4=Input
'F1 P27 =AN5=Input
'F2 P26 =AN6=Input
'F3 P25 =AN7=Input
'G0 P34 =AN3=Input
'G1 P33 =AN2=Input
'G2 P32 =AN1=Input
'G3 P31 =AN0=Input

B0 VAR BYTE
B1 VAR BYTE 'General Purpose Counter
B2 VAR BYTE 'Value Of ADC Channel
B3 VAR BYTE 'ADC Channel Value after processing
B21 VAR BYTE
B22 VAR BYTE
B26 VAR BYTE

clear

TRISB = %01100000 'Sets Pins to Input or Output
TRISC = %11111100 'Sets Pins to Input or Output
TRISD = %00000000 'Sets Pins to Input or Output
TRISE = %11111000 'Sets Pins to Input or Output
TRISF = %01011111 'Sets Pins to Input or Output
TRISG = %11111111 'Sets Pins to Input or Output

PORTE.1 = 0
PORTB.7 = 1

DEFINE OSC 12
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 0
DEFINE LCD_RWREG PORTE
DEFINE LCD_RWBIT 1
DEFINE LCD_RSREG PORTE
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTE
DEFINE LCD_EBIT 2
DEFINE LCD_BITS 8
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50

ADCON1 = %11101111

DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 50

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 20h
DEFINE HSER_BRGH 0
DEFINE HSER_SPBRG 64
DEFINE HSER_CLOERR 1

GoTo STARTUP

STARTUP:
LCDOut $FE,1,"Data Logger V1.0"
LCDOut $FE,$C0,"Reseting "
PortB.0 = 1
PortB.1 = 1
PortB.2 = 1
Pause 100
PORTB.0=0 : PORTB.1=0 : PORTB.2=0 : PORTB.3=0 : PORTB.4=0 : PORTB.7=1
PORTC.0=0
PORTF.5=0 : PORTF.7=0
GOTO MAIN

MAIN: LCDOut $FE,1,"Press button "
LCDOut $FE,$C0,"to start logging"
PAUSE 100
'IF PORTC.2 = 0 Then START
Goto start 'MAIN

START: SOUND PORTB.7,[127,5]
GOTO Sens1

SENS1: ADCON0 = %00010001
ADCON1 = %11101010
ADCIN 1, B2 'Read Value of RTC
B3 = B2 >> 2
ADCON1 = %11101110
ADCON0.0=0
PAUSE 100
LCDOut $FE,1,"Sensor 1 = ",#B3
PortB.0 = 1
PAUSE 50
Portb.0 = 0
B3 = 123 'Set B3 to known value for testing Port
HSEROUT [DEC B3,13,10]
PAUSE 100
GOTO SENS1

END

Here is an example of what comes out (using Serial Communicator)

À0>0ð0~€0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>Àp~0ð0>À0>0ð0>À0>pð0>À0>0ð0>À0>0ð0~€0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>Àp~0ð0>À0>0ð0>À0>pð0>À0>0ð0>À0>0ð0~€0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>Àp~0ð0>À0>0ð0>À0>pð0>À0>0ð0>À0>0ð0~€0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>À0>0ð0>Àp~0ð0>À0

Would somebody please help me, I've done all the usual "try everything/anything" " late nights" "
Regards Mark Scotford
[email protected] (remove the X to reply)
- 10th July 2006, 14:26
mister_e

Code:

DEFINE HSER_RCSTA 90h DEFINE HSER_TXSTA 20h DEFINE HSER_BRGH 0 <-- Don't exist DEFINE HSER_SPBRG 64 DEFINE HSER_CLOERR 1 <-- HSER_CLROERR

@12MHZ what is the expected baudrate? 2400?
using the calc i done few month ago
@12 MHZ you must use the following

Code:

DEFINE HSER_RCSTA 90h DEFINE HSER_TXSTA 20h DEFINE HSER_SPBRG 77 ' 2400 Bauds DEFINE HSER_CLROERR 1

about now?
- 10th July 2006, 14:46
Mark Scotford

Steve, you beat me to it, I was just downloading your Calculator program (thank you for sharing your work with us).

I posted in the new values Unfortunaly there is still garbage coming up in Serial Communicator (see example below) although it does seem more consistent.

ðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽ ðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽ ðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽ ðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽðàpøà~øàŽ
- 10th July 2006, 15:03
mat janssen

When you see that kind of data,you will be sure that the baudrate is not propper together with the parity and the number of data and stopbits.
Try to figger out what is the right baudrate. You can play with your settings of your read program
- 10th July 2006, 15:45
Mark Scotford

Slight correction to the wording of my original post. It should have read 12Mhz Crystal clock and not 10, although I did have it right in my coding as far as the DEFINE OSC 12 was correct. I could not work out why my calculations were wrong when compared to the results from Steve's excellent calculator (link shown below). A stupid mistake, but after correcting things, it still does not make any difference to the problem I am having. I have tried changing all the Parameters in Serial Communicator to all the different combinations of settings available and still no joy.

http://www.picbasic.co.uk/forum/atta...tachmentid=316
- 10th July 2006, 15:54
mister_e

1 Attachment(s)

Or the config fuses are not set correctly, or the OSC speed is not the right one OR the MAX232 circuit is bad OR there's a little hardware problem, OR the serial communicator is not set properly OR all DEFINEs are not written in UPPERCASE.

Bellow is tested and work on a 16f877.. but it shouldn't make any difference whatever PIC you're using...

Code:

define OSC 12 DEFINE HSER_RCSTA 90h DEFINE HSER_TXSTA 20h DEFINE HSER_SPBRG 77 ' 2400 Bauds DEFINE HSER_CLROERR 1 START: hSEROUT ["HELLO, THIS IS A TEST",13,10] PAUSE 100 GOTO START

<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=959&stc=1&d=1152544022 ">
- 10th July 2006, 16:14
mister_e

mmm... what about if ...

Code:

define OSC 12 RCSTA1=$90 TXSTA1=$20 SPBRG1= 77 ' 2400 Bauds DEFINE HSER_CLROERR 1 START: hSEROUT ["HELLO, THIS IS A TEST",13,10] PAUSE 100 GOTO START
- 10th July 2006, 16:33
Mark Scotford

Steve, I get this out, and I have my Serial Communicator set up the same as the prevous posters

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- 10th July 2006, 17:35
mat janssen

Is your powersupply oscillating?
Did you mount a capacitor over the supply points of the chips?
- 10th July 2006, 17:48
Mark Scotford

Yep, all chips have a 104 Cap near-by. Hold fire a while on this problem chaps. I tried programming an EPROM version of the processor instead of using my beloved ICEPIC2, and I am getting nothing happening, unfortunetly I have to go out now, but will continue tomorrow.
- 11th July 2006, 10:36
Mark Scotford

Appologies are due, especially to Steve and Matt. I made the fundamental mistake of believing what I was being told, a colleague said he had given me a known working board. The problem was the Loading Caps on the Oscillator crystal were of the wrong value (too high a value) which were not enough to completely cripple my ICEPIC2 but were enough to affect the speed.

I am now getting comms. and I did that thing of jumping up and down when the word "hello" appeared in Serial Communicator.

Thanks to everybody who helped and sorry if I wasted your time.
- 11th July 2006, 11:05
Mark Scotford

Just as a side issue, I plugged my ICEPIC2 back in, and I got garbage out again, on checking I find that ICEPIC2 uses its own clock of 4Mhz, (in my defence I got this secondhand so I do not have the manual) 4Mhz is the frequency I normally use on my PIC projects, so it has not been an issue before. Anyway just changed the crystal to 4Mhz, changed the settings in my code, run ICEPIC2 again and everything is working fine, so I am off and running, thanks to all.
- 11th July 2006, 14:44
mister_e

may happen dude. Nice to know you find the problem and learned from it.

Have fun!