HERSOUT2 (Weird problem)

[Megahertz]

My baud settings are as follows:

DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER_CLROERR 1 ' Clear overflow automatically
DEFINE HSER_BAUD 9600
DEFINE HSER_SPBRG  51 ' 9600 Baud
BAUDCON.3 = 1         ' Enable 16 bit baudrate generator
DEFINE HSER2_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER2_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER2_CLROERR 1 ' Clear overflow automatically
DEFINE HSER2_BAUD 14400

my code is as follows:

com var byte[12]

GETPIC:
		PAUSE 3000
		COM=0
		GOSUB SYNC
GOTO GETPIC
; UART2 IS CONNECTED TO THE CAMERA (www.4dsystems.com.au/downloads/micro-CAM/Docs/uCAM-DS-rev7.pdf)
; UART1 IS CONNECTED TO MY PC
SYNC:
		HSEROUT2 [$AA,$0D,$00,$00,$00,$00]
		HSERIN2	1000,SYNC,[COM]
		HSEROUT [$AA,$0D,$00,$00,$00,$00]' this statement and the ones below should not execute
		HSEROUT	[COM,13,10]
		HSEROUT2 [$AA,$0E,$0D,$00,$00,$00]
	GOTO GETPIC
RETURN

I should not get any response on my PC as I have removed my MAX232 and there is no way the data can go to the camera. But I get the following:

AA 0D 00 00 00 AA 0D 0A

why is com getting loaded with AA 0D 0A and then after a few loops of the same, it changes.

[HenrikOlsson]

Hi,
I guess a schematic of your setup would help, at least for me. But I guess that when you "remove" the MAX232 (provided it's located between the PIC and the camera (you DO have the RS232 version of the camera and not the TTL version, right?) the USART input on the PIC is floating, tricking the HSERIN2 statement into believing it's actually received something so the execution falls thru to the HSEROUT statement

Another thing that sticks out is you have COM declared as an array of 12 bytes and the response from the camera response to a SYNC is, as far as I can see, 6+6 bytes but you're only grabbing the first one with your HSERIN2 statement. Then it all starts over and there may be a residual byte in the USART buffer.

/Henrik.

[Dave]

This looks like a loop to me...
SYNC:
HSEROUT2 [$AA,$0D,$00,$00,$00,$00]
HSERIN2 1000,SYNC,[COM]

[Megahertz]

Hi,
I guess a schematic of your setup would help, at least for me. But I guess that when you "remove" the MAX232 (provided it's located between the PIC and the camera (you DO have the RS232 version of the camera and not the TTL version, right?) the USART input on the PIC is floating, tricking the HSERIN2 statement into believing it's actually received something so the execution falls thru to the HSEROUT statement

Another thing that sticks out is you have COM declared as an array of 12 bytes and the response from the camera response to a SYNC is, as far as I can see, 6+6 bytes but you're only grabbing the first one with your HSERIN2 statement. Then it all starts over and there may be a residual byte in the USART buffer.

/Henrik.

Ok, lets start solving the puzzle.

1) The camera is RS232 type
2) USART was floating. I tied it high and no reply back now - this problem is solved (cheers for that)

secondly can you suggest on how do I get these 12 bytes if HEX8 is the highest I can use

[HenrikOlsson]

If you know the length of the response, 12 in this case:

HSERIN2 1000,SYNC,[COM\12]

Since the normal response packet (except image data) seems to be 6 bytes and the camera response to a SYNC is an ACK (6 bytes) and a SYNC (6 bytes) I'd probably do it in two steps

COM1 VAR BYTE[6]
COM2 VAR BYTE[6]
HSERIN2 1000,SYNC,[COM1\6]
HSERIN2 1000,SYNC,[COM2\6]

[Megahertz]

If you know the length of the response, 12 in this case:

HSERIN2 1000,SYNC,[COM\12]
[

Not quiet sure about this. Doesn't seem to be valid.
I have instead declared 12 different variables and trying to get the response in them...i.e. - HSERIN 500,SYNC,[COM,ID,P1,P2,P3.....]

But it does not work, must be something with the baud, any idea what is the MAX baud we can do with 8MHz osc. I will appreciate if you can show as to how you can calculate it.

[rsocor01]

Not quiet sure about this. Doesn't seem to be valid.

The following text is taken from the manual. You will probably need to include the STR modifier.

STR ArrayVar\n{\c}
Receive string of n characters optionally ended in character c

must be something with the baud, any idea what is the MAX baud we can do with 8MHz osc.

Since you are dealing with HSEROUT2 (Hardware), my guess is that the answer to your question will be in the PIC datasheet.