Red Echo

July 9, 2010

The success of the rhythm robot project got me really excited about making DJ gear, and I have ideas for half a dozen additional devices, along with some vague plans for possible future commercialization. Two of the gadgets need to do a lot of audio processing: one is a specialized percussion synthesizer, and the other is a multiband/multichannel compressor. I’ve been reading up on filters, oscillators, op-amps, and the like, and I think both of these projects could reasonably be done with a simple microcontroller driving an array of analog audio hardware, but I keep coming back to the fact that I’m basically a software guy building hardware in my free time. I don’t really want to spend weeks soldering up RC networks: especially not when I could just get a faster processor and do it all in code, which is cheap and easy to fix. So, I’m looking into 32-bit microcontrollers, and the most interesting line so far seems to be the ARM Cortex-M3.

Here are a few Arduino-style dev boards based on the ARM Cortex-M3:

  • Maple: 72 MHz, general USB, IDE based on Arduino, $50
  • Cortino: several models, 36-72 MHz, serial USB, no IDE (use gcc), $40-$70
  • ARMmite Pro: 60 MHz, no USB, Coridium IDE, $30

6 Comments

  1. Hi there,

    check out Xmos CPU’s. Some have nick named them “the son of the Transputer” – embedded parallel processing CPU’s. The CPU’s have been designed by the relatively newly formed XMOS company and employs several of the brains behind the Transputer chips. I am moving to them from PIC cpu’s as they are far more capable and look to be great fun to program :)

    http://www.xmos.com is the URL I believe.

    I’ll be interested to read your thoughts on them,

    Cheers,

    Wardy

    Comment by Wardy — July 9, 2010 @ 8:31 am

  2. Thanks for the pointer – I’ve never heard of XMOS, but it sounds like their chips have some interesting FPGA-like flexibility that might be really useful for DSP.

    Comment by mars — July 9, 2010 @ 9:22 am

  3. Wow, hilarious, you can get an XMOS chip set up as a plug-in board for an Arduino – “the XArduino board provides Arduino applications with a 400 MIP’s multi-threaded 32-bit co-processor, as well as providing a VGA video output and PS/2 keyboard/mouse input for Arduino application.” That tail definitely wags its dog…

    Comment by mars — July 9, 2010 @ 9:31 am

  4. Mars,

    I have to confess, until last friday, I had never heard of Arduino… Very nice systems – and as you say, especially when paired with an xCore cpu.

    I guess I kinda got stuck in the “do it yourself via PIC” mode. xCore doesn’t include DAC or ADC like the PIC, but these are easily added.. When added, you suddenly have something as capable yet a great deal more powerful. Some fun is to be had!

    Comment by Wardy — July 12, 2010 @ 8:59 am

  5. I never had much success with PIC; I think there was just too much to learn before getting to “hello world”, and I focused on more approachable projects. Arduino is nothing special from a technical point of view, but it streamlines the path from “write code” to “blink LED” so much that it was easy to jump in and make things that actually worked, and once you’ve hit that point it’s easy to build on it.

    The open platform is important, too. Unlike some of the other beginner-oriented microcontroller kits, it’s nice to know you can scale up from an Arduino to a manufactured PCB of arbitrary complexity without ever having to ask permission or pay licensing fees.

    It really is a great feeling, regardless of the technology, to be able to reach out into the real world and make actual things happen!

    Comment by mars — July 12, 2010 @ 12:20 pm

  6. Sounds like I need to look into Arduino more. Pic’s are good, but as you say, they are not quite as straight forward as one would like.

    It would appear that Arduino have taken a very sensible approach with their licensing – let’s hope other industries take note ;-)

    I have spent many months working on a PIC project. Trying to squeeze so much performance out of the little blighter wasn’t fun and began to prove impossible. I like the idea of a streamlined path. While it can be fun, it is also a hassle reinventing the wheel….

    Comment by Wardy — July 12, 2010 @ 1:33 pm