Build your own 4-channel logic analyzer

If you’re just getting into hobby electronics chances are there are lots of tools you’d like to get you hands on but can’t yet justify the purchases. Why not build some of the simpler ones? Here’s a great example of a 4-channel logic analyzer that can be your next project and will add to your arsenal for future endeavors.

As you can see, [Vassilis'] creation uses a cellphone-sized LCD screen as the output. It is powered by four rechargeable batteries and driven by an ATmega8 microcontroller. He’s designed the tool without power regulation, relying on the ATmega’s rather wide range of operating voltages, and a few diodes to step down that voltage for the LCD screen.

As you can see in the clip after the break, alligator leads can be used to connect the test circuit to the inputs (don’t forget the ground reference!). Thee buttons at the bottom let you navigate the captured data by panning and zooming. Perhaps the best design feature is the single-sided circuit board which should be quite easy to reproduce at home.

[via Dangerous Prototypes]

25 thoughts on “Build your own 4-channel logic analyzer

  1. Very neat project – or so I’m guessing – I couldn’t stomach listening to the seven and a half minutes of crappy music and fumble finger configuration just to unearth the minute or so of useful information.

    Project makers – for the love of whatever you find holy, learn how to edit your videos. TL:DR applies to videos as well.

    As to the background music – DON’T. Unless you’re a band promoter (and if you are – kill yourself now) – just stop with the freakazoid music choices.

    If your INFORMATIONAL video can’t stand on it’s own without crappy background music – that’s a hint – you need to EDIT FOR CONTENT.

    1. I have to agree with you. I avoid videos, simply because they’re serial by nature, instead of parallel, like a text file or a web page.

      Advice to makers: post a summary with links to details. Include a link to a video if you’d like, but don’t skimp on printable pages.

      And lose the music…short and sweet. Edit, edit, edit!

      1. Agreed, I’d rather read a good tutorial than watch a how-to video. On the other hand, sometimes a video is better, so having both is best of all.

    2. I’ll have to agree with you on the music. Even though it is a decent looking build (certainly useful for par-time or broke hobbyists), music just makes your video unappealing to people who just want the info.

      Anyway, I’d add a plug for those logic inputs. Maybe something with alligator clips already installed. Could salvage the audio cable from the back of an old cd-rom drive. I used one to re-locate a Parallax compass module once, so those pins should fit.

    3. I have to agree. While I really appreciate people posting up videos of their work the background music is so distracting that i can never watch them with the sound on.

      Especially heavily synth pop music that sounds like it came off the 1980′s era Buck Rogers episode.

    4. @vonskippy
      I respect your opinion on the music track I had choose. I don’t have much experience in creating videos and any well-intentioned comment is welcome. I think in a 7.5 min video is not too hard for you to watch it.
      I would prefer of focusing on the logic analyzer circuit and if you want tell me your opinion about the logic analyzer or some improvements I could made on the circuit.

  2. I think it’s be cool if some enterprising hacker took some of the work building higher-speed FPGA-based analyzers and made a low-component count uber-instrument including LA, couple of moderate-speed scope channels, DVM, and component sense and then hooked it up to one of those ubiquitous chinese touchscreen LCD modules.

  3. Press the mute button, and fkucing get over it! And if you don’t have the time or the skills to either watch the whole video and/or fastforward in the video itself, but have the time to complain here with more than five lines, please go post a video yourself. Whiners!

      1. It should be a fairly easy thing to do with a Userscript Firefox plugin. This uses the Greasemonkey scripting engine. See my simple script here to change ebay auction times from PDT to CST.

        http://userscripts.org/scripts/review/109974

        You would just need to recognize their “username says:” and replace all text between there and the next Reply with [b]MUTED!!! STFU username!!![/b]

        ;-)

        It would be great to dynamically add usernames to the script… not sure how to do that part though.

        Send me an email if you want to collaborate on it.

  4. Nice build, but I would recommend beginners to buy a Logic (or cheap chinese clone) instead. Better specs,
    user experience, probably cheaper too.

    1. Microcontroller works on 16MHz crystal. You can get a better perfomance by overclocking the ATmega8 to 20MHz by using a 20MHz crystal instead of 16MHz one.
      In this case you will need a re-compilation of the source code by setting the frequency to 20MHz.

  5. This is an awesome use of an old cell phone screen, speaking of which, can anyone guide me towards information of palm treo screen pinouts? I have a slew of old palm treo’s (with cameras) my IT dept were going to thow out (60 in all), which I salvaged, is it possible to hack the screens for fun things like a second (mini) monitor for a modded pc case, while still utilizing the touch screen feature? Camera, to screen and flash memory storage, etc.?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s