Monday, 6 August 2012

Arduino-based Audio Cable Tester

I love the Arduino platform - it makes it so quick and easy to get things done.

The local music school had a need to test a bunch of audio cables (1/4" and XLR) in a hurry in preparation for the annual students' concert.  Yes, it can be done with a multimeter but if you have lots of them to do this becomes very tedious very quickly.  Sounds like a job for an Arduino





It does XLRs also...



The work is all done by an Atmel Atmega mircocontroller



All of the development work is done in the Arduino environment.  Once it was all working I just transferred the microcontroller onto a piece of perfboard (so that I could reuse the Arduino board for my next project).  The connectors on the far-left of the board (connected to pins 1,2,3,7 and 8 ) allow the Arduino board to be used as a programmer (see http://arduino.cc/en/Tutorial/ArduinoToBreadboard). That link explains how to configure the Arduino to use the built-in 8MHz RC clock in the Atmega so no external crystal is required (neither accuracy nor flat-out CPU speed are remotely important in this application).

I also stuck a normal ICSP connector on it so that it can be programmed using a normal programmer (bottom-left corner).  This is handy:  once the code was complete I was able to blow the Arduino boot-loader away so that the sketch starts immediately rather than after a pause.  The downside is that if I want to use an Arduino to program it again I need to reinstall the boot-loader (for which that ICSP header will be very useful !)

The source-code is posted here.  The comments in the code list the required connections.  I haven't bothered to draw a circuit-diagram but if anyone wants one just leave a note in the comments below and I will post it here.

 

 

 

11 comments:

  1. This comment has been removed by the author.

    ReplyDelete
  2. This comment has been removed by the author.

    ReplyDelete
  3. This comment has been removed by the author.

    ReplyDelete
  4. Uh?... Why write comments if they will be deleted?...

    ReplyDelete
    Replies
    1. I'm sorry for that. To be honest, I don't know how it happened. I didn't deliberately delete anybody's comments and I didn't notice them missing until I saw your comment here. I'll take a look to see if I can figure out what happened.

      Delete
  5. Would you like to write a blog about audio cable ? The sample is free for you. If you like, please contact me. Thank you.

    ReplyDelete
  6. Would you like to write a blog about audio cable ? The sample is free for you. If you like, please contact me. Thank you.

    ReplyDelete
  7. Dear Eamonn McGonigle!
    Please send the schematics to my email address: k_alajos at freemail.hu
    Thanks!

    ReplyDelete
  8. Hello, good project. thanks for sharing this. Please can you send me the schematics, my mail is: felipebetancur.lo@gmail.com

    ReplyDelete