Multiplexer channel selection

[skimask]

Yes ... Ok, But ALSO inside a CODE window ...???
could we talk about a BUGGGGGGGGG ????

I don't know if it's a bug or not. Maybe bbCode doesn't handle nested tokens, or at least that nested token correctly, maybe it was intended to be that way.

[Castor]

Please stay on topic.

Here's a summary: I have two pesky devices in my circuit. A multiplexer and a decoder.The multiplexer is connected as:

MUX
'------------
'RA5	INH
'RA1	A
'RA2	B
'RA3	C
'RA4	D
'------------

notice how the selection channels are on consecutive pins thus making things easy for selecting the channels:

'mux channel selection
'low inh_mux
'for i= 0 to 15
'       Porta =  (Porta & %11000001 ) + (i *2)	'port masking for cycle purposes
'next i

On the other hand the decoder pins are scattered across PORT B and PORTC:

'DCD
'----------
'RE2	G1,G2	
'RB7	A
'RB6	B
'RB5	C
'RC6	D

here's the code i've devised:

'dcd channel selection
low g_dcd
for i=0 to 15
	portb = (portb & %00011111 ) + (i rev  3)<<5
	portc = (portc & %10111111 ) + (i<<3)
next i

The PORTB pins selection works fine (meaning lines A, B and C of the decoder behave as I expected). But line D (the only one on PORTC) gives me a headache. Am I missing something in the mask ?

[skimask]

Please stay on topic.

Guess what? Free help! Deal with it.

'dcd channel selection
low g_dcd
for i=0 to 15
	portb = (portb & %00011111 ) | ( ( i rev  3 ) << 5 )
	portc = (portc & %10111111 ) | ( i << 3 )
next i

OR don't ADD

[Acetronics2]

Guess what? Free help! Deal with it.

'dcd channel selection
low g_dcd

for i=0 to 15
	portb = (portb & %00011111 ) | ( ( i rev  3 ) << 5 )
	portc = (portc & %10111111 ) | ( i << 3 )
next i

OR don't ADD

to get rid of the i lower bits for portC ...

i would have used

portc = (portc & %10111111 ) | ( i.3 << 6 )

but, it's me ...

Alain

[skimask]

portc = (portc & %10111111 ) | ( i.3 << 6 )[/code]

I've tried to do something like that before. If I remember right, the fact that i.3 is a bit didn't work well with the << 6. It ended up shifting itself out into nowhere and always ended up being a '0'.
Maybe that was back in the day, in an older version of PBP or something. It just seems to me like that didn't work very well.

[Acetronics2]

Hi,

I did at test on the breadboard this morning ...

Everything fine ...

Alain

[Castor]

This is the winner:

portb = (portb & %00011111 ) | ( ( i rev  3 ) << 5 )
	portc = (portc & %10111111 ) | ( i.3 << 6 )

I've tried both in MPLAB SIM but

	portc = (portc & %10111111 ) | ( i << 3 )

doesn't mask the port right.

THANK YOU. Problem solved

[Acetronics2]

Good news !

Just for the fun ...

How many boards saved ???

Alain