HSERIN woes

[ad8bc]

I am developing a program using HSERIN in automatic mode. The basic idea of this application is to have a device attached serially to a computer running some specifit software. When this software sends a "1", "2", or "3", the device is to turn on a green, yellow, or red LED by itself (i.e. turn off any LEDs already on). On receipt of a "0" the leds are off.

I made a working program using regular serrxd which works fine... however, since there is to be a simple routine to flash the LED if a "F" is received from the computer, I went on to design code using HSERIN in background mode on a 40X2 so I don't lose any communications while the program is pausing for the flash modes.

It works... sort of.

0, 1, 2, and 3, the ASCII characters I expect per the program, don't work. Instead (and I found this out by accident), the characters that actually work are > : 6 and 2 (decimal 62, 58, 54, and 50).

There is a pattern here but I don't know what it means... I can't figure it out.

Any ideas?

Also (unrelated) I noticed it didn't matter if I used inverted mode or not on the hsersetup... is this important?

Code below.

'	STACKLIGHT2.bas
'	Test program for 40X2 development kit
'	WITH HSERIN!!!
'
'	OUTPUTS:
'	B.0	GREEN LED
'	B.1	YELLOW LED
'	B.2	RED LED
'
'	OPERATION: If serial data from attached computer = 1, 2, or 3, turn on
'	green, yellow, or red LED by itself.  If data is 0. turn off leds.
'	If data is F, enable flash mode, if data is S, disable flash mode



'=== Constants ===
symbol STACK = outpinsB
symbol char = W3
symbol flash = B0
symbol GREEN = %00000001
symbol YELLOW = %00000010
symbol RED = %00000100
symbol BLANK = %00000000
symbol abit = 500

'=== Variables ===
' none

'=== DIRECTIVES ===
#com 7				' SPECIFY SERIAL PORT
#picaxe 40X2			' SPECIFIY PICAXE TYPE
#no_data				' SAVE DOWNLOAD TIME
'#terminal off			' ENABLE TERMINAL WINDOW

'=== MAIN PROGRAM ===
dirsB = %11111111			' PORT B ALL OUTPUTS

hsersetup B9600_8, %11 		' baud 9600 at 8MHz, Invert, Background
	HSerPtr = 0			' Reset (background) write pointer
	HSerInFlag = 0		' Reset reception indicator
	Ptr = 0			' Reset read pointer
	@Ptr = 0			' Clear the first scratchpad location

'STACK=%00000100
main:
	if hserinflag = 1 then gosub datain
	if char="F" then let flash = 1 endif
	if char="S" then let flash = 0 endif
	if char="0" then let STACK=BLANK endif
	if char="1" then let STACK=GREEN endif
	if char="2" then let STACK=YELLOW endif
	if char="3" then let STACK=RED endif
	if flash = 0 then goto main
	pause abit
	if hserinflag = 1 then gosub datain
	let STACK=BLANK
	pause abit
	goto main
	
datain:
	ptr = 0
	char = @ptr
	hserptr = 0
	hserinflag = 0
	return

 

[inglewoodpete]

I suspect your problems lie the the misconfiguring of the hSerSetup command. The X2 devices have a 3-bit mode parameter. While the 3 bits need not all be specified if the leading bits are zero, I think they should be something like %111 or %101

The left-most bit is the receive polarity, which would usually be N or 1. The middle bit is the send (transmit) polarity control, which has no affect on your posted code.

0, 1, 2, and 3, the ASCII characters I expect per the program, don't work. Instead (and I found this out by accident), the characters that actually work are > : 6 and 2 (decimal 62, 58, 54, and 50).

I noticed that the expected 4 characters 1, 2, 3, 4 (ascii 49, 50, 51, 52) were appearing in reverse order (ascii 62, 58, 54, 50), vaguely suggesting a polarity error. I'm not 100% sure but give it a go.

 

[ad8bc]

Thanks Pete, that was exactly the problem. I changed the setup to %101 and it worked perfectly.