nanogui: Thread: SetTop box Development [sorta an advert]

Ok,

Bush Internet.TV has gone bankrupt :) Only £17.9mil in debt. They have
an ABUNDANCE of kit left over (I think at the last count approx 30,000
units) at retailers across the UK - they were, the weekend past,
retailing at around £9.99 each at a TIme special, £19.99 at Toys'R'Us
with a Tenner mailback rebate, probably a few places on the net wanna
get rid of them too - have a google.

I got one, of course, and they will run Linux, a port is already
underway - I think they will make good setup boxen, apparently the
hardware alone lists at £200 cost, they are ARM based, 33k6 modem, PC
Style Parallel Port [D-Link-620 anyone?], Custom IR, and SCART ports and
contain, internally jumpers for 2 additional RS232 ports (on top of the
2 already in use), PS2 Kb & Mouse, IDE, Floppy, Gameport and probably
others I have forgotten etc, etc - They also come with an IR Keyboard &
Mouse-ish, albeit a crap one (you can buy a better one, apparently, am
yet to see it at a discount price - List ~£30, IIRC) and are currently
running a cutdown version of Ant & RiscOS. Finally, the innards of the
Cirrus Logic/ARM CPU used seems to be VERY well documented :)

Thought I woudl post a general "heads up" for people to keep an eye open
for, should they be interested....

Just thought of it as another ViewML/NanoX platform, that's why I bought
mine :)

	-Happy Hacking
	 Darran

> contain, internally jumpers for 2 additional RS232 ports (on top of the
> 2 already in use), PS2 Kb & Mouse, IDE, Floppy, Gameport and probably
> others I have forgotten etc, etc - They also come with an IR Keyboard &

The box I took apart you would need to be very very good at soldering to
fit those connectors.

> yet to see it at a discount price - List ~£30, IIRC) and are currently
> running a cutdown version of Ant & RiscOS. Finally, the innards of the
> Cirrus Logic/ARM CPU used seems to be VERY well documented :)

It seems to be a sawn of version of the acorn reference box for the 7500
series ARM

> The box I took apart you would need to be very very good at
> soldering to fit those connectors.

Standard surface mount chips. All very unpleasent. Running solder down
bent paperclips is my prefered method of mangling the board - although,
upon investigation with a mag.glass and half an ounce of clue, there
does seem to be jump-pads for a double-decker PS2 socket.  - labeled
SK1 - although mine were under a little round yellow sticker :)

 If you hold the box, topside up, front to your left. To the south-east
of the pair of (4Meg each?) ROM's.... I think :) Just "above" the
largest of the 3 connectors on the video/power daughterboard. But I'm no
hardware geek.

> > Cirrus Logic/ARM CPU used seems to be VERY well documented :)
>
> It seems to be a sawn of version of the acorn reference box
> for the 7500 series ARM

Yes, Agreed but the Socket Mounted ROM's make the whole show so much
easier to upgrade.

Next on the shopping list, a "flasher"  *grin*

	-Darran

> -----Original Message-----
> From:	Darran D. Rimron-Molloy ####@####.####
> Sent:	Tuesday, January 29, 2002 1:33 PM
> To:	Alan Cox
> Cc:	nano X
> Subject:	RE: [nanogui] SetTop box Development [sorta an advert]
> 
> 
> > The box I took apart you would need to be very very good at
> > soldering to fit those connectors.
> 
> Standard surface mount chips. All very unpleasent. Running solder down
> bent paperclips is my prefered method of mangling the board - although,
> upon investigation with a mag.glass and half an ounce of clue, there
> does seem to be jump-pads for a double-decker PS2 socket.  - labeled
> SK1 - although mine were under a little round yellow sticker :)
> 
	[Simon Wood]  
	The real trick with surface mount is to let the solder do the work. You don't need a small iron, I use on with a 4mm wide tip.

	For chip caps/resistor put a small blob on one end and then hold the chip with a pair of tweezers lightly touch the solder blob with the iron and the solder will pull the chip into place. Then solder the other end.

	For bigger components (i.e. chips) tack them in place at the corners, then use lots (!!) of liquid flux and create a ball of solder between the pins and the iron. You can drag the ball of solder along the pins without the iron touching them. Remove excess solder by cleaning you iron and then dragging it down the length of a pin, this removes a little solder each time.

	It does take a little practice at getting the right amount of solder (so you don't have to remove too much), but it really isn't that hard.

	That said I am still in awe of a technician who put a 208 pin BGA down with a hot air gun!!!

	Simon.

Actually you can get excellent tools for surface mount work from Jameco.com
they have hot tweezers, and small irons and other SMT tools for really low
prices..  $59.00 for hot tweezers is insanely low.. as work paid $1200.00
for the ones I use daily.   and SMT work is really easy if you get a liquid
flux pen. the secret is to use flux and alot of it. I was intimidated by SMT
work 2 years ago.. today I only prototype with SMT as regular DIP chips are
awkward and bulky....  Now if I could figure out how to solder a BGA chip
onto a board...  I really want to prototype with the ZFMicro MachZ Computer
on a chip.

-----Original Message-----
From: Simon Wood ####@####.####
Sent: Tuesday, January 29, 2002 8:50 AM
Cc: nano X
Subject: RE: [nanogui] SetTop box Development [sorta an advert]



> -----Original Message-----
> From:	Darran D. Rimron-Molloy ####@####.####
> Sent:	Tuesday, January 29, 2002 1:33 PM
> To:	Alan Cox
> Cc:	nano X
> Subject:	RE: [nanogui] SetTop box Development [sorta an advert]
> 
> 
> > The box I took apart you would need to be very very good at
> > soldering to fit those connectors.
> 
> Standard surface mount chips. All very unpleasent. Running solder down
> bent paperclips is my prefered method of mangling the board - although,
> upon investigation with a mag.glass and half an ounce of clue, there
> does seem to be jump-pads for a double-decker PS2 socket.  - labeled
> SK1 - although mine were under a little round yellow sticker :)
> 
	[Simon Wood]  
	The real trick with surface mount is to let the solder do the work.
You don't need a small iron, I use on with a 4mm wide tip.

	For chip caps/resistor put a small blob on one end and then hold the
chip with a pair of tweezers lightly touch the solder blob with the iron and
the solder will pull the chip into place. Then solder the other end.

	For bigger components (i.e. chips) tack them in place at the
corners, then use lots (!!) of liquid flux and create a ball of solder
between the pins and the iron. You can drag the ball of solder along the
pins without the iron touching them. Remove excess solder by cleaning you
iron and then dragging it down the length of a pin, this removes a little
solder each time.

	It does take a little practice at getting the right amount of solder
(so you don't have to remove too much), but it really isn't that hard.

	That said I am still in awe of a technician who put a 208 pin BGA
down with a hot air gun!!!

	Simon.

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Simon Wood wrote:
 > Remove excess solder by cleaning you iron and then dragging it down
 > the length of a pin, this removes a little solder each time.


Be careful not to overheat the chip doing that. A better way is to use 
solder wick (AKA desoldering braid) a few pins at a time, alternating 
sides so that you're not concentrating too much heat in one place. Put a 
clean length of solder wick over the pins, apply a small amount of 
solder the tip of your iron, and press down on the top of the wick for a 
few seconds (on the opposite side to the pins, to draw the solder through).

After soldering, lightly drag a sharp pointed craft knife along the top 
of each row of pins so that it makes a clicking sound- when you hit a 
dry joint you can usually feel (and hear) the difference. Then use a 
continuity tester to make sure that the power supply lines aren't 
shorted together before you try powering it up. If it doesn't work, 
quickly power it down again and look for shorts on all the other lines.

With the higher density packages a fairly low powered optical microscope 
with top illumination is very useful for visual inspection.

As always, remember to wear protection (the anti static variety). I've 
destroyed more than one device in the past by not heeding that advice.

-- 
------------ Alex Holden - http://www.linuxhacker.org ------------
If it doesn't work, you're not hitting it with a big enough hammer