Gummi Worm Clock

I forgot to build something for the Bay Area Maker Faire Bring A Hack event. I started this on April 7th. The Faire is May 16th.

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The rarest gummi of them all, the gummi RGB seven-segment clock. Carved by gummi artisans who work exclusively in the medium of gummi.

It's a clock using very cool seven-segment displays available from Adafruit. Each segment of the display is an RGB LED. Yes, it will look cool.

Holy balls, does that ever look awesome.

This is a clock made with RGB seven-segment LED modules available from Adafruit. The form factor will be an oversized Raspberry Pi Hat; this clock needs to connect to the internet (for some reason) and I have some other ways to use these numbers.

  • Live Update From Bring A Hack

    Benchoff05/18/2015 at 06:10 0 comments

    Maker Faire, the greatest show and sale on Earth is finally over. That means it's time for Bring A Hack, which laen from OSH Park has conveniently organized at the BJ's Pizza Palace in San Mateo. It's time to shine, which is good, because I really need to PWM these displays down:

    I wrote the code for this at the bringahack, which makes me the most badass person possible. Also, free beer until we drank it all.

  • Moving to Moteino

    Benchoff05/03/2015 at 13:15 0 comments

    I scrounged up enough stuff at the techcrunch JavaScript-a-thon to put together a microcontroller board for the clock:

    Yes, that's a hot glue conformal coating. The rest is some 40ga kynar wire I had sitting around. I know it works, now it's just a matter of coding it.

    Here's the pins for my future reference:


  • Perhaps the Raspi was a bad idea

    Benchoff04/29/2015 at 18:38 0 comments

    I originally designed this as a Raspi Hat for some reason I don't remember. I believe an Internet-connected clock was part of the decision, and of course the blog cred for putting a clock on a Raspi.

    I am now reconsidering this choice.

    I'm not getting PWM timing that looks good with only software PWM available on the Pi. A microcontroller would be a much better choice, so I'm getting one of these, sticking a Trinket on it, and plugging in the display/clock board.

    It's really just a matter of putting the R, G, and B OE signals on different timers... A duino can do it...

  • Digits Finally Working

    Benchoff04/28/2015 at 06:53 3 comments

    I can't say I'm completely happy with it - I'm pretty sure I screwed up something on the colon LEDs, and a Raspi really isn't the right tool for this (but a Pi2 would...), but it works.

    Now it's just a matter of turning it into a clock. I'm still trying to wrap my head around how the programming for that is going to go. After that, it's done. Until I repurpose a Pi Hat prototyping thing as a microcontroller breakout board or something...

  • Because Someone Is Probably Wondering What The Inside Of These Displays Look Like

    Benchoff04/23/2015 at 01:19 1 comment

  • DS3231 RTC Up And Running

    Benchoff04/22/2015 at 22:53 0 comments

    The boards arrived and the I2C RTC is up and running, confirming that at least some of the board works. I'm a little hesitant about soldering those driver chips... I need a hot air setup.

    If you need some instructions on setting up the I2C, here you go

  • Missing Pins And Eagle Footprints

    Benchoff04/20/2015 at 16:00 0 comments

    I recieved my order from Adafruit this weekend. Checking out the pins for the RGB seven-segment displays, there are a few slight differences.

    Yes, missing pins! There's no problem; the missing pins aren't connected to anything. They do, however, allow for a bit more flexibility in routing a project that uses these displays.

    Other than that, these displays match my Eagle footprint, so I'm going to call that a win. Now I'm only waiting for the OSHPark boards to arrive, and I can start assembly.

  • I can confirm the Eagle LED2472G Footprint

    Benchoff04/13/2015 at 19:45 0 comments

    Just got an order from Mouser. The Eagle footprint I created for the LED2472G driver is good. It's in the Github.

    Here's a size comparison:

  • So Who Wants To Build The World's Coolest Clock?

    Benchoff04/12/2015 at 07:07 5 comments

    Before I dig into this, I'm just going to say, no, I'm not going to build this. This is simply an exercise in procrastination. It does look pretty cool, though.

    Okay, with the Pi version out to fab, I figured the clock doesn't need that much RAM to drive the display, the Pi version already has a RTC, and we're basically working with shift registers here. For the fuck of it, let's design a version with a microcontroller.

    And so a dozen hours were lost.

    This version (it's in the github now) features:

    • An ATMega328p microcontroller. Why not?
    • A DS3231M Real Time Clock - no crystal required!
    • Four LED2472G LED drivers. Why change what might work?
    • Improved power supply. Yes, it's just a 7805, but that'll be more than enough to drive all the displays at maximum brightness
    • Hour and Minute buttons, because I hate clocks around daylight savings time. No, a single button doesn't work, and every time DST comes around, I need to disconnect the battery in my car, and reconnect it exactly at noon.
    • An ESP-8266. Why? Because there was space on the board for one, and I don't give a shit.

    There we go, a microcontroller-based RGB Seven-Segment clock that has all the functionality of the Pi version and is completely overengineered for a clock. Does your clock have WiFi? No? Yeah, mine does.

    I'm not going to build this. It's insane, impractical, and I'm already spending $200 on the prototype to see if the LED2472 drivers will work. I just made this one because I'm bored.

    If anyone wants to make it, go ahead. It might work. Files are in the Git. I'd like to see it made, and you could probably sell a few of them on Tindie with some SEO on Pinterest or something...

  • Connecting Pins

    Benchoff04/11/2015 at 01:41 0 comments

    Since I'm waiting two weeks or something until I get some boards and parts, It's a good enough time to figure out how this thing is going to be programmed. The first step to that is documenting how I laid this thing out. Here's the pin map:

    Now it's a matter of how to connect this to the driver. Here's the datasheet for the driver. It gives me eight RGB drivers. Here's a table, because the editing tools on here are awesome:

    How the displays are connected
    Driver output numberSegment of the display

    And the pinout:

    ...and that's how you route these things with any semblance of sanity:

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rgbdigit wrote 07/11/2016 at 10:54 point

The project looks nice, maybe  next time ty using my solution for the wireing and controling problem 

See  hope you like it  

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xobmo wrote 04/23/2015 at 00:24 point

You should make a shield that has REAL Gummi Worms on it, pressed onto pin headers at the ends of each segment...

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Blecky wrote 04/29/2015 at 03:50 point

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Stefan-Xp wrote 04/08/2015 at 18:20 point

Awesome Project :) Do you want to control it by the Raspberry Pi?

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Benchoff wrote 04/08/2015 at 18:20 point

Yep. That's the plan.

There aren't many connections to the pi, though: only data, clock, latch, and some /OEs. The RTC is just I2C. I only need a few bytes of RAM to drive the display, so theoretically I could do this with a small ARM or ATtiny.

I wanted to connect this to the Internet for some reason, so a Pi was the natural choice.

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Stefan-Xp wrote 04/08/2015 at 19:04 point

Great thank you for your Reply! 

I'm still sad that i didn't get into Pi programming :(

Then Good luck and have fun ;)

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Stefan-Xp wrote 04/08/2015 at 19:07 point

BTW: Am i right, that the Hour and Minute Separations have the same color later on? 

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Benchoff wrote 04/08/2015 at 23:56 point

Yeah, The colon of 5mm RGB LEDs are going to be the same color all the time. Laying out the board, this was the best way to do it. I think it'll look better, but - meh - this is just something I want to make and it needs to be done in a month. Less than a month, actually.

The Github now has the beginnings of a non-pi version that makes a little more sense form-factor-wise. It's controlled with an ATMega328p. When I do the layout for that, I might make the seperator colon individually addressable. I need to work out the kinks with the Pi version first.

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Eric Hertz wrote 04/08/2015 at 15:45 point

"Holy balls, does that ever look awesome." You took the words out of my mouth, and probably every other blinky-light fanatic's as well.

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davedarko wrote 04/08/2015 at 15:48 point

double-clicked \r\n newlines? or pure excitement? :p love the blinky stuff, too!

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Eric Hertz wrote 04/08/2015 at 15:50 point

dag-nabbit! I thought I could clear that up before it was noticed. 

Apparently a bit overly-excited :)

Gummy-Worm-Segment LEDs!

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