Month: November 2017

Sneaky Serial Port

Tried out serial communication b/w PC (Windows 7 using hterm) and notebook (Fedora 23 using bash+stty).

Could get data from notebook to PC but not vice versa. Reading from /dev/ttyUSB0 just would not show any received data.

Tried out all combinations of parity bits, stop bits.

Turns out all data arrived but LF was missing, so nothing was displayed in the shell….

That’s one wasted afternoon.

VLSI tools in 500 LOC or Longing for Attention

My VLSI tools take a chip from conception through testing. Perhaps 500 lines of source code. Cadence, Mentor Graphics do the same, more or less. With how much source/object code?

– Chuck Moore, the inventor of Forth –

Now, I’ve seen chip design tools by the likes of Cadence and Mentor Graphics. Astronomically costly licenses. Geological run times. And nobody quite knows what they do.

– –

Installing Altera Quartus Prime on Fedora 23

Installation did run without problems.
Executing >>quartus from the ~/altera/15.1/quartus/bin folder has no effect whatsoever, no error is printed on the command line.
Adding the above path to $PATH has no effect.
Running >>quartus 2> quartus.stderr to redirect stderr to a file uncovers the following error:

>>cat quartus.stderr
>quartus: error while loading shared libraries: cannot open shared >object file: No such file or directory”

Aha, so a file is missing, why can’t quartus just tell me this?

>>sudo dnf search libpng12
>libpng12.i686 : Old version of libpng, needed to run old binaries
>libpng12.x86_64 : Old version of libpng, needed to run old binaries
>libpng12-devel.i686 : Development files for libpng 1.2
>libpng12-devel.x86_64 : Development files for libpng12

>>sudo dnf install libpng12

Ok let’s try again…


Finally, it works.

Building up a Sound System

Here’s a suggested approach on how to grow your home sound system from a simple stereo system to a full grown 7.1/2 surround sound theater.

  1. Start with a simple stereo system. 2 speakers, front left and front right.
  2. Add a subwoofer for improved bass.
  3. Add a center speaker.
  4. Add 2 speakers, rear left and rear right. This makes a 5.1 system.
  5. Add 2 speakers, effect left and effect right. This makes a 7.1 system.
  6. Add another subwoofer. This makes a 7.2 system.
  7. That’s it.

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