Art and Technology are Friends

Wave JT – LED chaser with Joule Thief

Wave JT is a multi-function LED chaser/scanner/sequencer. Wave JT incorporates Joule Thief to power the LEDs, so it operates on just a single AA battery.
Wave JT has over 16 sequence patterns, and speed can be adjusted by double/triple tapping the button. It’s the most compact yet versatile LED chaser.

Sequence patterns include many variation of the classic “Larson Scanner” from “Knight Rider”, random sparks, fade in/out, flashing, etc.

Even though there is only one button switch on Wave JT, you can control many things with it.

> Purchase Wave JT kit or PCB

22 Responses

  1. John

    Hi what do you use to program the pic 16F1823, As i want to change the sequence, Thanks John

    April 6, 2014 at 10:55 am

  2. Hello LED Artist.

    Thanks for such a fun site with awesome LED goodies. I had received a Wave JT for a project I’m working on, after a few days this idea came to me as to what to do with this neat item. I hope you enjoy as much as my daughter and myself do. I present the first and only Altoids Tin/ave JT personalized handheld nightlight/flashlight. YouTube video link below :)

    July 4, 2013 at 8:57 pm

  3. Backe

    hallo again sir.
    thanks for your answer. i have now progam the chip and get it working. took some hours to fix and understand the PIC2 uppgrade. nice. i tried to skip the joule thief and connect it directly to 5 volt vith a switch connected to 5 v also. it starts with one led at the time and when switch is pushed pmw secuence starts for one turn then its dead until i reset power. must pin 2 have some clockfrequency? i like this ide and chip becouse its 1/4 in price compered with other chip and your sequencing is very nice. is it possible to run directry from 5 volt without joule thief?
    best regards
    Backe, Sweden

    October 7, 2012 at 3:52 am

    • If you want to skip the voltage booster and supply 5V directory, connect the power supply to the IC pin 1 rather than pin 2. Pin 2 controls the booster circuit and also checks the button switch.
      You can use the #2 and #3 holes of the ICSP header which you can access from the back side of the PCB. The hole with the triangle pointing is the #1. #2 hole is for +5V, and the #3 is GND/Earth.


      October 7, 2012 at 7:59 pm

  4. Backe

    hallo sir
    how do i program PIC16F1824 with a pickit2.
    it says no supported device.
    best regards, Backe, Sweden

    October 5, 2012 at 11:40 am

  5. The colors on the LED are incredible!

    August 22, 2012 at 5:22 pm

  6. Patrick Friedel

    Yeah, seeing your Wave JT made me consider getting out Eagle and seeing if I could arrange 6 RGB LEDs on a reasonably-sized board since I have a couple dozen RGB LEDs going spare. But I’m still debugging the current setup – if I try to put in too many modes (like 3 or 4 versus the current 2) into my main function switch, it gets visibly jerky. I haven’t imported it into AVR Studio to see what the compiler is doing to it, though. But that’s on the internal 8MHz RC clock. If I upgraded to the 20 pin tiny2313 and clocked it at 20MHz, I suspect a lot of the quirkiness would go away.

    But there’s something intrinsically fun about a design that simply uses a microcontroller, some resistors and 4 LEDs to make glowing shinies. Overcomplicate it too much and some of the appeal is lost.

    And with 9 pins, you could drive 9*8=72/3=24 RGB LEDs if you ran them in a charlieplex. Common anode or common cathode, either one works, I’m using both. The pin to LED LUT I use is different of course, but the electrical characteristics are similar enough. But 24 LEDs would be more than enough for a chaser! You could get away with 6 pins driving 8 RGB LEDs (leaving 6 “LEDs” unfilled) and freeing up a pin or two for the mode switch. I just don’t know how much the altered duty cycle would affect your response curves. Might be a fun experiment. Of course, I say this with a variety of AVR charlieplex toolkits under my belt, I don’t know what the PIC environment looks like.

    August 6, 2012 at 12:48 am

  7. Thurston

    Maybe this is a dumb question but what did you use to program the PIC?

    August 3, 2012 at 3:57 pm

    • I used PICKit 2 and 3. I tried them both just because I had them both… You can use either one, or ICD 2, 3, etc.

      August 3, 2012 at 3:59 pm

  8. Patrick Friedel

    Just because I don’t think I’ve ever seen the full description – how do you regulate the joule thief’s output into something that a microcontroller is happy about? I have a nice attiny-driven 4 RGB LED charlieplex arrangement that I’d love to run from a joule thief since it already gets ~13-14 hours from a CR2016, but the notion of feeding the unfiltered transients from a JT into a poor unsuspecting microcontroller gives me the heebie jeebies.

    (Also: Totally jealous of your RGB camerawork. Every last video I’ve ever shot of mine has been utterly blown out unless I adjust their maximum brightnesses in the code, and then the colors go all wonky…)

    August 2, 2012 at 1:59 am

    • Patrick Friedel

      Ah, found the instructable link with schematic and the question is answered.

      August 2, 2012 at 2:03 am

      • Hello Patrick,

        Glad you found the instructables. I should post more info here nowadays…
        BTW I’d love to see whatever you are working on. Send me pics or links please.

        August 2, 2012 at 10:12 am

  9. Glad I subscribed to you. VERY nice products. My Compliments.!!

    July 30, 2012 at 1:29 pm

  10. Wil

    Why not with rgb leds, like the aurora ?

    July 29, 2012 at 4:24 pm

    • With the 14 pin PIC, I can only control 3 RGB LEDs. That wouldn’t be much fun…

      July 30, 2012 at 12:35 am

      • sparr

        assuming you have 9 outputs… you can multiplex 6 RGB LEDs with that, or charlieplex 24 RGB LEDs.

        August 3, 2012 at 1:12 am

        • Yes with 9 output pins, you can drive up to 72 LEDs via Charlieplexing. However I wanted the LEDs to be able to fade nicely so I used my unique PWM method. Which eliminates the possibilities of Charlieplexing. Also, RGB LEDs are often 4 pin devices with either anodes or cathodes connected together, which eliminates the use of Charlieplexing as well.

          August 3, 2012 at 1:18 am

          • Patrick Friedel

            Ah, that’s not _entirely_ true – is using charlieplexing to drive 64 RGB LEDs, but his software API only drives them at 100% per channel, so you only get the 7 primaries (red, green, blue, yellow, teal, purple, white). I already had been using a non interrupt driven softPWM in other similar small projects, so I decided to try it out in RGB space. Right now I think it works out to something like 6 bits per color, after all the scaling and optimizations.

            Anyway, here’s a youtube of one of my more recent development videos: – although that might be running off of the arduino development board. I know this one is off of the ATtiny:

            August 5, 2012 at 11:10 pm

            • You got me thinking… Yes I _can_ drive 6 RGB common anode/cathode LEDs with 9 pins.
              I don’t know – are 6 LEDs enough for a chaser?


              August 5, 2012 at 11:25 pm

            • P.S. I watched the videos. Very nice.
              BTW I’m doing software PWM in 8 bit resolution. I believe that can be done with AVR as well. The clock has to be 20 MHz to run the PWM fast enough though.

              August 5, 2012 at 11:31 pm

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