Video update on Drum-machine progress

Here’s a video update on where I am with my Drum-machine project. In the past few months I’ve implemented a fair few new features and sorted out some long standing bugs.

  • A new menu mode using the joystick to navigate.
  • Added control over the LCD Backlight.
  • Added a simple Reverb mode.
  • New LCD driver code to render graphics to a buffer and squirt it out to the LCD via 9bit SPI.
  • Includes a basic graphics library with some widgets to make creating screens easier.
  • Fixed an odd issue with LED’s flashing out of sequence. I had my MAX6957 ports all out or order.
  • Added RUN LED flashing to every 4th beat.
  • Implemented loading and saving to one of 16 JSON files on the SD card.
  • Added a Tuning mode to allow you to individually set the volume and adjust the playback rate of each instrument/sample.

9 thoughts on “Video update on Drum-machine progress

  1. Pingback: Introducing the ChipStomp : A Digital effects pedal built with a ChipKit DP32 and a Stompshield | Catmacey's stuff

  2. hello there and great work on the drum machine
    really nice job and looks lots of fun too

    i would like to suggest you involve an encoder for menu surfing
    but also more importantly for value changes
    ideally with a speed vs resolution feature – meaning the faster you turn the blunter the increment changes and the slower the finer
    (and perhaps a small fader for things one might like to change quickly – volume being a classic)

    from many years of electronic instrument use – synths and drum machines and fx units etc i can sure you that you and anyone else who gets to use it will be glad it has one (at least one and / or faders)
    buttons presses really slow down parameter changes but also are fatiguing – albeit incredibly mildly but it does still detract from the creative moment

    if you have a look at whats going on at NAMM 2015 right now you’ll notice ‘analog’ synths making a massive comeback
    whilst notionally this is about the sound it also has a lot to do with ‘immediacy’ of control
    and the last several years have seen a return towards what the press calls “….the knobbier the better..”

    anyway – none of that is meant to detract from your work in any way – and in fact i would probably be interested in buying one

    so i will leave you with my first thought
    great work and good luck with your continuing progress

    • Hi Ade,
      I’m sure you could make a drum machine using a PIC16 or 18 but this particular project isn’t going to work for you without some significant modifications.

  3. Hello! Very interested to make this device πŸ™‚ I am wondering, if any blank PCBs available? I already ordered Nokia LCD, and now I am about to order a PIC32, but – question of PCB: if those not available, I will order DIP version and make it perfoboard, if I cold get somehow a PCB, I will order SOIC . Thank you! πŸ˜‰

    • Hi Juris.
      I’ll be happy to send you a PCB if I have any spare. It’s been a while since I worked on this project so I’m not 100% sure if I have any left or not.
      If I don’t have any then you can always order your own using the Eagle files in the GitHub repo.


      • I was checking prices, and – oh boy, that LED driver is most expensive thing in drum machine, at distributors it costs like 4 times price of PIC controller πŸ˜€ And, I guess, ebay ones might be fakes. So, hmm, I will probably make without LEDs at first, or look for some addressable substitute for that MAX. Also, about PCBs, if it happens that you look around for spare PCBs that left (or not), would be super if LCD breakout could be available. Thank you a lot in advance.

      • Hi Juris, yes it true they are quite pricey.
        I originally started using it because I got some free samples in DIP package direct from maxim using their sampling service. That’s something you could try too, they’re quite generous.
        I have been on the lookout for a replacement for a while – mostly due to the price – but it seems that most similar drivers are either use i2c or some other not SPI interface for communications which is not great is you are already using SPI for everything else. Or they only have a small number of LED ports (10 or so) which would require multiple parts. Or they are perfect but are only available in a really hard to use package like QFN. So I’ve stuck with the MAX6957. That and the fact that it is really easy to control (and I have all the drive code already written) make it worth the price, at least for now anyway.

        Good news for you is that I do have one last PCB left and also a break-out for the LCD too.
        Send me your address details by email and I’ll get them on their way to you.

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