[sdiy] ARM Cortex M4F chips with CODEC interfaces & DIY-friendly packages

[nvawter]

I learned to solder the 0.5 mm LQFP-64 stm32f405 for my Music-Optimized 
Breakout
Board (MOBB) using this tutorial:
https://www.youtube.com/watch?v=3NN7UGWYmBY

I re-watch it every time I get a batch of 3 in.  I do the soldering 
first thing
in the morning when I am fresh and before I have any coffee.  I use a 
binocular
magnifier at 10x, but many people say a single magnifier works great.
I use the same techniques as in that video and I have had 100% success
(about 9 boards).  In fact, as I got a bit confident with it, I started 
to
understand the physics of "drag soldering" and even to drag solder a few 
pins
at a time.  I get my tools and materials from:
http://www.zeph.com/smd_solder_process.htm   except for my iron which is 
a WES51
with a 1/32" tip.

When I tell people this, they *inevitably* tell me "just put it in a 
toaster
oven!"  as if I've been running around with my shoes unlaced for four
decades complaining about tripping over my own two feet.  In fact, the
oven is a brilliant next step, but I do not need it yet.

If people wanted to make my MOBB a community project I would be willing 
to share.
I'm having trouble with the DAC output at the moment, but other than 
that I have
made a half-dozen instruments with it.  (It's a two pole passive 
Low-pass filter,
but the output is way too low.)  I do most of my work in Linux with gcc 
and gdb
in C.

Additional options include:

1. Martin Klang's board that he and his group use in the Hoxton
Owl is also a viable option.  It's very similiar to mine, but it uses 
the larger
chip (144-pin) and has 24 analog inputs and I believe the 24-bit codec 
is built-in?
(I can't find the schematics on their website, but go ahead and crawl 
around http://hoxtonowl.com)

2. the LXR drum synthesizer uses an stm32f4 is open source, but I'm 
having trouble finding
their schematic, too:  http://www.sonic-potions.com/home

3. Eric Brombaugh made a nice, little stm32f4 board with a 16-bit codec 
and SD card slot.
It had some small issue with the SD card in the first rev, but the codec 
worked great
and I don't know if he took it any farther

-Noah



On 2014-09-16 09:15, Robin Whittle wrote:
> I mentioned an ST chip in a UFQFPN48 package:
> 
>   http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1577/LN1877/PF260148
> 
> because it had fewer pins than LQFP-64 packages - so I thought it might
> be more DIY-friendly.  However, after looking at the data sheet, page
> 122, I think this is not the case.
> 
> As far as I know, 0.5mm LQFP packages could be soldered by hand, by
> filling the area with solder and removing what is not needed with wick
> or a desoldering tool.  I have never tried anything like this - can
> anyone report success or otherwise?
> 
> However, the UFQFPN packages have no leads - just solder pads on the
> inside edge of the bottom of the package, so there would need to be
> solder paste put in place with a stencil, precise alignment, perfect
> heating etc, and no chance for inspection or solder sucking if things
> didn't work out well.
> 
>   - Robin
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