Subject:
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Re: Help! Hanyboard Assembly Testing problem!---I think solved!
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 16 Jan 2002 08:34:21 GMT
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Viewed:
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5784 times
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There was a very undetcible component-side solder bridge between pins 2 and
3 of RP4. I might not know until tomorrow when I can get a replacement for
RP4 (apparently I'm not very good at desoldering, and I didn't see the
bridge at all until I [forcibly] removed rp4)
Thanks. It probably would have been a while until I caught that one.
Sam
"LightMan" <lightman@lightman.nospam.org> wrote in message
news:Gq0tBp.7Do@lugnet.com...
> Hi,
>
>
>
> Thanks for your reply.
>
>
>
> RP4 has the part # 88102G, and adjacent pairs of pins have resistance of • 1k
> (ie, 4 discrete resistors).
>
>
>
> Ok, Tell me if this sounds really strange... R15 is installed, but tested
> at about 1k ohms, not 47k. I remove the resistor, and it tests at 47k • once
> removed from the board. I test contacts where r15 was, and there is
> resistance of 1k. So there is another path between +5 volts and the other
> side of this resistor. Just for kicks I verified this by turning on the
> board again without this resistor, and it pretty much behaves as it did
> before.
>
>
>
> I'll pursue this line of thought a little farther, but will answer your
> other questions in case I'm barking up the wrong tree.
>
>
>
> I did try many times putting the board in bootstrap mode without the • serial
> interface being plugged in, and the green light just stays on. This was • the
> first symptom that I had a problem.
>
>
>
> I also performed the loopback test mentioned below. Everything is A-OK!
>
>
>
> Once again, thanks for your help, and please let me know what you think
> about my findings stated above. I'm going to explore that a little more
> tonight.
>
>
>
> Sam
>
>
> "Fred G. Martin" <fredm@alum.mit.edu> wrote in message
> news:C16EFB08-09D3-11D6-BF56-0003934F857A@alum.mit.edu...
> > Sam, can you check the serial input circuit. if this is not correct,
> > then the 6811 won't stay in boot mode. make sure RP4 is a 1Kx4 resistor
> > pack (4 discrete resistors) and not a 1Kx7. also make sure R15 is
> > installed. see http://handyboard.com/schemv12/cpu.gif .
> >
> > also, try putting it in boot mode without the serial interface
> > attached. this should be possible. see the serial debug instructs at
> > http://handyboard.com/faq/winindex.html to verify that your serial int
> > works right.
> >
> > Fred
> >
> >
> >
> > On Tuesday, January 15, 2002, at 02:01 AM, LightMan wrote:
> >
> > > Ok,
> > >
> > > RP4 was fine.
> > > I've put a logic tester "MODA" line on the chip (from what I can • figure,
> > > this is this pin that gets the signal from the stop switch), and it is
> > > recieving a signal when I press the stop switch.
> > >
> > > I verified that the reset pin was getting a signal from u12. It is.
> > >
> > > I also verified that that TxD pin recieves signals when I send data
> > > through
> > > the serial line. It does.
> > >
> > > So what could be wrong? I guess everyone's on vacation, or would have
> > > gotten a reply by now. Anyone here? Anyone? I'd really like to get
> > > this
> > > thing working.
> > >
> > > Sam
> > >
> > > "LightMan" <lightman@lightman.nospam.org> wrote in message
> > > news:Gpv72r.1E1@lugnet.com...
> > > > Hi!
> > > >
> > > > I'm still can't get the chip to go into bootstrap mode. I've double • checked
> > > > I've got all the components installed in the correct direction, and
> > > > inspected the entire board for shorts, and have found none! What can • I
> > > do??
> > > > I'll try resoldering the processor chip socket. I tried to search
> > > > for a • new
> > > > processor at Frys Electronics, but they don't have them... I'll try a
> > > > few
> > > > surplus warehouses tomorrow/Monday. Any ideas, anyone???
> > > >
> > > > The "power fluctuations" have gone away, as I have cleaned off all
> > > > extra
> > > > flux, and used a soft brush attached to a dremel tool to clean and
> > > > polish
> > > > the board (I hope that's all I've done ;-)... but it is a fairly soft • brush,
> > > > and hasn't seemed to damage the board at all.
> > > >
> > > > The "power leak" (Power light, and battery light stay on when power • is
> > > > turned off, but only when charger board is connected.) is coming from • max232
> > > > chip on the charger/serial board. I remove the max 232 chip, plug
> > > > the 2
> > > > boards together, apply power to the charger board, and the problem • goes
> > > > away. Is this "normal"? Looking at the HB schematics, pin 5 from • the
> > > RJ11
> > > > Jack goes through a few resistors, and connects to both the power • led,
> > > > and
> > > > +5v, so if the max232 chip were to "leak" power to pin 5 of the RJ11
> > > > jack,
> > > > it would go to pin 5 on the HB, and power the board in some limited
> > > > way. • I
> > > > have replaced the max232 chip, and the problem is still there, so
> > > > either
> > > > this is normal, or there is something VERY weird going on.
> > > >
> > > > Also I don't understand how the processor can cause the green led to • go
> > > out,
> > > > when in bootstrap mode. it looks like the power led is directly
> > > > connected
> > > > via 2 resistors to a +5v supply. Hmm maybe I should test rp4? If • rp4
> > > > was
> > > > bad, it could cause both these problems.
> > > >
> > > > Sam
> > > >
> > > >
> > > >
> > > > "LightMan" <Lightman@lightman.nospam.org> wrote in message
> > > > news:GpsqtI.FuI@lugnet.com...
> > > > > Hi!
> > > > >
> > > > > I'm putting together my shiny new HanyBoard. I've got to the point • where
> > > > > I'm testing the serial line/power led on the HanyBoard itself.
> > > > >
> > > > > The processor won't seem to go into bootstrap mode(ie, the green • light
> > > > won't
> > > > > go out, and attempts to download the bootstrap code fail in IC).
> > > > >
> > > > > The previous testing step, testing the processor's clock seems to • work...
> > > > I
> > > > > have a logic probe, and pin 5 causes the logic probe to emit a • fairly
> > > fast
> > > > > blinking light, accompanied with a beeping sound.
> > > > >
> > > > > All other tests have passed as well. I have also tested the stop • switch,
> > > > to
> > > > > make sure it was functioning--it shorts when the button is pushed.
> > > > >
> > > > > Other things to note, that I find strange are:
> > > > > 1) somtimes the power led flickers once the board is fully powered. • This
> > > > > seemed lessened once I cleaned to bottom of the board with a pcb • board
> > > > > cleaner/degreaser (I thought it might be good to get rid of some of
> > > > > the • flux
> > > > > from soldering). Also this rarely happens when the board is on • "external
> > > > > power" from the serial interface board/charger.
> > > > >
> > > > > 2) when powering the board from the serial interface board, and I
> > > > > power • off
> > > > > the handyboard using the switch, the power light will stay lit, and
> > > > > the
> > > > > battery light will also come on, so I may have some voltage getting
> > > > > onto • the
> > > > > board.
> > > > >
> > > > > 3) The download fails, but I appear to have com communications • correct...
> > > > I
> > > > > can see the serial light flicker as the PC attempts to d/l the boot • strap
> > > > > code. Also for some reason the power led on the handyboard will
> > > > > flicker
> > > > > when the boot strap code is downloaded.
> > > > >
> > > > > I would assume that I have some sort of tiny short somewhere, but I • don't
> > > > > know where to look. Any ideas?
> > > > >
> > > > > Sam
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> >
>
>
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