Jonome - now with funky perspex case!

  • Greetings all! Real life has distracted me from Chronoming for a little while, but here's a quick chance to describe what I've been working on. **This project still has a few little problems to be ironed out, so I wouldn't recommend copying it //quite// yet.** Have a look at the attached pics to accompany the text - captions in italics as we go through.

    I started off with a simple Arduinome based on Sparkfun buttons and a stripboard shield (I attached some diagrams to [[|this]] thread a while ago - I hope to do a better post on this another time). It was the usual single-colour setup, and worked fine with the monome apps that I tried, but I had soldered up the breakout boards with RGB LEDs for future expansion (i.e. this project).

    The Jonome's layout is intended to be identical to that of [[|Owen and Jordan's Chronome]], only using the Sparkfun buttonpads and a home-made stripboard shield instead of PCBs. As the TLC5940 LED drivers used in the Chronome sink current from the ground pins of the individual LEDs, the buttonpad boards require a little modification. Specifically, the LED-GND traces need to be severed so that the grounds are separated rather than connected in rows. Then each LED needs its own connection to the shield/TLC.

    **Note: Having a little trouble getting attachments to upload, and trying to link to image files is producing some weird results, so for now full size versions of the pics and diagrams available [[|here]].**

    //**Pic 1:** The RED, GREEN, BLUE, SWITCH, and SWT-GND connections are made in the usual way (i.e. same as the Arduinome). The LED-GND traces are cut (stanley-knife cuts just about visible) and each LED given its own GND lead://

    //**Pic 2:** The LED-GNDs are wired up to 4 2x8 IDC connectors (C, D, E, F) in such a way that the LEDs 0-63 are connected to sequential pins of the TLCs: the first TLC connected to the first two rows (LEDs 0-15), the 2nd to the next two rows, and so on://

    //**Jonome Stripboard Shield Diagram:**//

    //**Pic 3:** NB: Components above the upper red line are part of some troubleshooting experiments, and can be ignored for now://

    //**Pic 4:** Likewise ignore the 4 capacitors://

    //**Pic 5:** Shield connected to the Mega://

    **Teething Problems ------------------------------------------------------------------**

    1. For a while I had a very strange problem: the board would sometimes run its program fine; other times it wouldn't. I checked over everything again and again, testing and re-testing the circuit. Eventually, I discovered that depending on how far one of the TLCs packages was inserted into its socket, it was //physically// pressing the Arduino's reset button //just// enough to cause problems! Quite the most baffling electronics problem I've come across, especially since the problem would obviously disappear when I removed the shield from the Mega to inspect it.

    So the moral of this story is to check the physical clearances of things! This could be solved by moving the offending TLC (3rd from the left on the diagram) one place to the left. In my case, I added spacers between the Mega and shield, enough to clear the button, but thin enough to make sure all the pins still contact correctly. //**Pic 6:**//

    2. I've been been having a problem with the LEDs dimming when lots of them are on, causing colour mismatches. See [[|this thread]], and please contribute if you have any ideas!

    3. During my experiments to power the LEDs separately, I suspect I may have blasted a sensitive pin with too much current, which has killed the bootloader on my Mega. It still runs the loaded firmware fine, but I can't upload any new programs. I have purchased a replacement Mega, but it's an R3, which seems to have complicated the serial-number-flashing step of setup. Hmm.

    Other than these three issues, I'm pretty happy with how the project is going: the buttons are working fine, and the device is behaving as it should. If I was starting from scratch (which I may yet do if I can't solve the dimming issue) I would space out the components on the stripboard a little more. I like the compactness of my setup, but it does mean soldering in some pretty tight spaces!

  • Lastly, and excitingly, I shall leave you with a tantalising glimpse of the case which has arrived this week. More shots of the fully-assembled beast will arrive in due course!

  • Hi Josephiah,

    Nice project! After seeing the pictures, I might suggest one possible area that could lead to the LED dimming issue. The TLC5940s are on your shield, and as such, the GND leads to each LED is very very long. This will create extra resistance along the lines, and might be contributing to the dimming effect. I know on both the Chronome, and the Octinct, the TLC5940s GND traces are kept as short as possible. Might be worth a look.

    Looking forward to seeing the final enclosure.

  • Cheers for that Owen, replied on the [[|other thread]] to keep all the troubleshooting stuff in one place.

    Here's couple of pics of the case. More to come when I get round to it, and will be happy to share case design files for anyone who's interested.




  • Ooh. Pretty.

  • beauty! Love the lines...

  • Chronome with this style case= Brainmelter.

  • @Cropsie,
    Can't really be done with a "direct physical manipulation" approach. e.g., you can't push the buttons with your fingers if the LEDs are arranged as a grid. (the button board is your enemy here; LEDs in the middle need to be suspended without their base obscuring the line of sight between one mirror and the other)

    What would work (and work well) is to build this as a secondary display, to perhaps sit behind you on stage, picking up signals from something like SerialOSnoopy to make its grid match the one you're actually touching.

    (I've given a lot of thought towards putting a large infinite-LED ring on each wall of an installation, echoing whatever's on my arc 4. Note, with that design, you could put an encoder in the middle for direct manipulation. You just need to be damned sure the thing's mounted securely to the wall. Nothing ends a show like your device shattering in a cascade of broken glass to slice up the audience, right?)