MSGEQ7 pain fun!

Taken from Distributted by CC BY 2.0

Several years ago I had ordered five MSGEQ7 to eventually build a graphic equalizer. During my first attempts at it, I didn’t use any capacitors and couldn’t get it to work, so I gave up.

Fast forward to earlier this year when I decide I’m going to do something with these chips (project to be shown later) and tonight I finally break them out and give it a go.

The datasheet provides a working example of how to properly use the chip and I built up that example circuit; however, that didn’t work.

Next, I new Sparkfun had an Arduino Shield for the chip and they give both code examples and their schematics. So, I built that up, modified their code and….nothing. Garbage output.

I look for a third source and find this blog post. So I build it up and still garbage output.

At this point, I’m loosing my patience. Now I have cheap Chinese breadboads and sometimes they aren’t the best and since the circuit was so simple, I just pulled out a sheet of perfboard and made it. Still, nothing on the output.

Really upset now, I go to my drawer where I have extras and I pull them out and start popping them into the circuit and observing the output. The second one gives different garbage output, same with the third and fourth.

Finally, on my last one, I get some useful output. It isn’t perfect and one of the channels is garbage, but it is something.

So, with a somewhat working chip, I start to resort the defective chips to make sure I gave them a fair shake. As I put them back in and looked at the serial monitor, I still got garbage back. 🙁

I’m none too happy at the moment with this chip. I think I’d recommend people to get premade breakout boards. Yeah, they cost over $10, but it’s easier and faster to check for defects.

In the meantime, I have my own breakout board so if I ever feel like ordering more, then I’ve got something to test them with.

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Eclipse Collage

Today was the big day! There was a total solar eclipse across the entire US!

Unfortunately, where I was at did not to a full 100%; however, I thought I’d show you part of what I did manage to get.

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Pantum P2500 on Linux

I’ve had a Pantum P2500W laser printer for a while and it’s a cheap B&W printer. I use it for printing journal articles and for making PCBs.

It does its job quite well and I’d even recommend it.

What’s good about this printer is that it supports Linux! (yay!) However, if you’re on a rpm based distro, then you’re kinda out of luck.

You can get the official driver here for Ubuntu or Debian.

Normally I wouldn’t write something, because you can just use Alien to convert it. Nothing big…

However, let’s look at this:

./ --to-rpm ./Pantum-P2500-Series-2.6.x86_64.deb
Warning: alien is not running as root!
Warning: Ownerships of files in the generated packages will probably be wrong.
Use of uninitialized value $field in string eq at Alien/Package/ line 262.
Use of uninitialized value in lc at Alien/Package/ line 630.
Use of uninitialized value in lc at Alien/Package/ line 630.
Warning: Skipping conversion of scripts in package : postinst postrm
Warning: Use the --scripts parameter to include the scripts.
Use of uninitialized value in lc at Alien/Package/ line 630.
Use of uninitialized value $_ in pattern match (m//) at Alien/Package/ line 673.
Use of uninitialized value $_ in concatenation (.) or string at Alien/Package/ line 674.
mkdir: invalid option -- '0'
Try 'mkdir --help' for more information.
unable to mkdir -0: at Alien/ line 257.

And you get nothing…so how do we fix this?

Well, we need to extract the data from the deb. We can do this with ar.[1]

mkdir ./Pantum-P2500-Series-2.6.x86_64
ar -x ../Pantum-P2500-Series-2.6.x86_64.deb

You’ll see that I did this in a new directory. In this case, you get “tar bomb’d”; however, I imagine that is the case for other debs as well.

Anyway, with that you’ll see that you have two tar archives. Extracting them, you’ll get a layout like:

├── control
├── control.tar.gz
├── data.tar.gz
├── debian-binary
├── postinst
├── postrm
└── usr
├── lib
│   └── cups
│   └── filter
│   └── pt2500Filter
└── share
├── cups
│   └── model
│   └── Pantum
│   ├── Pantum P2200 Series.ppd
│   ├── Pantum P2200W Series.ppd
│   ├── Pantum P2500N Series.ppd
│   ├── Pantum P2500NW Series.ppd
│   ├── Pantum P2500 Series.ppd
│   ├── Pantum P2500W Series.ppd
│   ├── Pantum P2550N Series.ppd
│   ├── Pantum P2550 Series.ppd
│   ├── Pantum P2600N Series.ppd
│   ├── Pantum P2600NW Series.ppd
│   ├── Pantum P2600 Series.ppd
│   └── Pantum S2000 Series.ppd
└── doc
└── pantum-p2500-series
├── changelog.gz
└── copyright

At this point, we have everything we need to get our printer up and working. As root, do the following:

cp -rv ./usr/share/cups/model/Pantum /usr/share/cups/model
cp -rv ./usr/lib/cups/filter/pt2500Filter /usr/lib/cups/filter
systemctl restart cups

From here on out, you can add the printer the normal way that you would want to.

For those of you who don’t want to go through the hassle of extracting the deb and all of that, I’ve put the x86_64 and i386 tarballs on the site for you to get.

You’ll still need to do the copy portion, but that’s really all there is to it to get this printer up and going.

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Remote Install of OpenSuSE

It’s time to update the network!

Most of the services I host have been running off of my main desktop which isn’t very safe, so I have this plan drawn out on my white board and I’m finally starting to implement it.

I’ll be using Tumbleweed from hereon out for my servers and I’ll stick with Leap for the desktop (because Nvidia…).

That said, I thought I’d try doing a remote install.

I plugged in a USB drive with the ISO “burned” on it and followed the standard procedure for remote install. A quick guide can be found here, but I’ll go over things just for fun.

At the boot screen, add the following boot options:

UseSSH=1 SSHPassword=unencrypted_password

I thought at that point, everything would be cool and I could just SSH into the box; however, it needs more user input than that.

You’ll first be required to say what language you want to use on your machine and then it’ll load Linux. After that, then it’ll prompt you for which network card to send a DHCP broadcast out to. This about five minuets, which is annoying to say the least.

I consider these prompts and the time it takes to be a problem. Suppose I wanted to just go into a datacenter, pop an install medium in, and put in those quick little boot parameters, then I’d be hosed as I couldn’t access my system remotely!

I know I’m nitpicking and that I should just do my installs with AutoYaST and the questions do actually make sense; however, it just isn’t what I expected.

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Rosabel Edney

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New Category! Wall of Shame

I’m going to start posting spam that I receive to my inbox.

The first post is in base64, so I’ll leave it as I got it; however, I hope to include full headers later on.

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Yvone Chen

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Nice little Hackathon

So I have an interview tomorrow and I was asked to show off a recent project I completed.

Well, I don’t really have one of those, so I decided to just make a project real quick.

I wound up making a webserver in about six hours (realize that includes taking breaks, having dinner, and so on). I think it does a good enough job to be honest. It probably has more memory leaks than FireFox, but I think it’s good enough.

I’d like to include the use of dlopen(3), but we’ll see how far I get on that tomorrow.

Anyway, if you want to see the code:
Here it is

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Problems with JSON and FOSS

So, over the past year or so, I’ve been introduced to JSON.

JSON is an alright format and is easier to write than XML (did I remember that close tag?).

However, my biggest gripe with it is the license.

Behold this statement:

The Software shall be used for Good, not Evil.

I think that was meant to be tongue in cheek; however, IBM didn’t think so and got special permission to use it however they see fit.[1]

This brings up a problem, clearly JSON is not “Free” data interchange. In fact, GNU points this out.

It appears to be heavily relied on for the Ruby community. Which is of course problematic if you’re a die hard GNU fanboy. Now, I appreciate the GNU GPL licenses (although they are not without their flaws); however, it isn’t my go to license. That said, I do have concern for that clause.

Maybe I’ll contact the Mr. Crockford and ask him to clear it up.

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SSL is live!

So, for those of you who want to connect securely, the option is now available.

Secure Version

This is made with my own CA and keys, so you’ll get a warning, but as long as these fingerprints match up, then you’re good:

SHA1 Fingerprint 6B:55:C4:32:6A:72:B6:CA:29:2A:CE:E7:24:FA:B8:44:EE:70:C8:7A
SHA-256 Fingerprint 46:B8:6A:6B:D8:FE:39:45:25:AF:EB:53:B6:0D:73:38:50:34:8F:EC:21:C9:8A:4B:D3:2D:B6:8D:5D:BE:A1:14

Eventually, I won’t be so cheap and I’ll get this sort of info from a trusted certificate authority; however, this works for now.

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