I'm confused

[Robotica1]

I had to start a new thread as for some reason I cannot reply to the last one. When I try I get the message:
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I don't know what it's all about but here's that schematic...oh no it isn't..I can't do attachments...I get told that I am currently viewing as a guest etc (even though I am logged in...but can't reply to my own posts?!?!?) So I'll try my previous trick of posting this and then editing it to attach a schematic...fingers crossed

[mackrackit]

Maybe I am missing something but... code does not match schematic.

symbol l9= porta.1

symbol l10= porta.2

symbol l11= porta.3

symbol l12= porta.4

Drawing has:
A1 going to l10
A2 going to l11
and so on...Maybe I am the one confused

As far as you posting goes contact Darrel for help.

[Robotica1]

Yeah sorry about that....originally the port settings were as schematic: l9=a0, l10=a1, l11=a2, l12=a3. I changed them later to check that it wasn't just something with a0 but as a few of you pointed out I can't use a4 for I/O so I shifted 'em back. Maybe the code I sent was the middle test 'era' as it stands the last 4 port settings are a0-->a3 respectively. I've tested this setup on 3 PICs and 3 bargraphs (2 green and 1 red) with the same result. So I tried a6....same result. Out of pure frustration I wired the a0 output to a totally independant standalone LED...which flashes perfectly at the right time. This would make me think that the problem is with the Bargraph. But if I just pulse l9 then it is fine and if you look at the original code there are two subroutines (standard and pulse) which work absolutely fine. I cannot for the life of me see any reason whatsoever why one LED would work perfectly with a signal whereas another would flash ever so briefly with the same signal yet work fine when another signal comes from the same line....totally inexplicable and maximum admiration to anyone who can work this out!!!

[mackrackit]

Ok, Looking at the data sheet in section 11 VOLTAGE REFERENCE MODULE on page 68.

11.5 Connection Considerations
The Voltage Reference module operates independently
of the Comparator module. The output of the reference
generator may be connected to the RA2 pin if the
TRISA<2> bit is set and the VROE bit, VRCON<6>, is
set. Enabling the Voltage Reference module output onto
the RA2 pin with an input signal present will increase
current consumption. Connecting RA2 as a digital output
with VREF enabled will also increase current consumption.
The RA2 pin can be used as a simple D/A output with
limited drive capability. Due to the limited drive
capability, a buffer must be used in conjunction with the
Voltage Reference module output for external connections
to VREF. Figure 11-2 shows an example buffering

I am sure Mister-E can clear this up if it is the problem, now I am in new ground

[Robotica1]

Thanks Dave, (and mister_e and all who've contributed),
I have to go to bed now as it's 3am and my boy's B'day tomorrow (today)....looks like I won't get the full coding down for his 'wrist scanner'...I'll work it out later and 'upgrade' him. Thanks again for all your help and if anyone actually puzzles this out I'll be all ears as to what's happening.

Good night all

[mister_e]

The voltage reference is disabled by default, but yeah, not bad to make sure of everything
CVRCON = 0 if my memory serves me well

with CMCON = 7 it usually enough.

Anyways, on this one, IF we want to have always the same brightness on ALL LED, we will need to do some TRIS and PORT tricks. Obviously our friend omit to add the resistor in his schematic, but no problem, i'm working on something right now.

For once, i'll try it on a SIM

Schematic is attached