Charlieplexed lighthouse version 2 PCBs have arrived

A long exposure makes it look quite funky

My version two charlieplexed lighthouse circuit PCBs (charliediscs) have arrived back from the Seeedstudio’s fab. I used the same deal as for my last boards, this time it took around 3 weeks in total.  That’s pretty good for 20USD!

The overall circuit is the same as the prototype I built two years ago but with some improvements to make it easier to use and also to allow you to use normal LEDs rather than surface mount packages. It’s mostly SMD but I’m still using the DIP package PIC12f683 (datasheet) as I have a whole bunch of them that I bought a while ago.


Two of the new boards. Seeedstudio sent me twelve in total.

Top side of the board. Note the hybrid LED pads that combine the SMD with a plated hole for normal LEDs. I also added a couple of mounting holes.

Bottom of the board. It's mostly the LM317 voltage regulator down here. If you were using a regulated supply you could by-pass it.

The board is designed to suit many type of LED package. Here's are some standard 603, 805 and 1206 packages (top) and a couple of oddballs (bottom)


You could also use some fancier packages such as these PLCC packages or the OSRAM PLCC side LED that I used on the prototype (top and bottom)


But for this one I'm going to use some super-bright 5mm blue LEDs that I've had kicking around for a while. I've bent them at a right angle so the light goes sideways.

Make sure you fit the LEDs with the polarity running in the same direction. It's doesn't really matter which way you choose as long as they are all the same.

All the LEDs are soldered in, just need to clip the legs.

By swapping around some of the pins this version can be programmed and then run with the ICSP connector still attached. No need to have the isolation switch that I needed on the prototype. It makes testing much easier.

Schematic for version 2. More or less the same as v1 but now the ICSP Clock line is used as the button input rather than as part of the charlieplexing. This means it can be programmed without needing to isolate the ICSP lines.

The original prototype (left) and the new v2 circuit (right). The new circuit is a bit bigger, partly to fit the hybrid LED pads in but also because the max size for the PCB deal was 5cm x 5cm so I thought I'd make the most of it. Note the red dip switch serving as the ICSP isolator for programming the prototype. We don't need that any more!

Another arty long exposure shot.

16 thoughts on “Charlieplexed lighthouse version 2 PCBs have arrived

    • It was the same cost. It’s all CNC routed anyway so I guess as long as it’s not a time consuming complex cut then it’s all the same to them.
      Yours will be in the post tomorrow by the way… 🙂

  1. Pingback: Lighthouse schematics and files « Catmacey's stuff

  2. Pingback: PIC 12F683, charlieplexed 12-LED disc with LDR and custom 1-wire network | WISH (Alpha)

    • Hi Winston,
      Yes I have around 6 spare boards for sale.
      They are 5 Euro each plus 4 Euro for shipping by registered post.
      If you send me a paypal payment to I’ll send you one out tomorrow morning.

      • do you have any of the boards still left and Do you have anything that is already assembled? I would like to buy one already done but i have a 12 volt power supply if it matters?

      • Hi Charles. I do have some boards left and I have one already made up with Blue LEDs that I would be happy to sell you for 25 Euro + shipping. If you would prefer one with white LEDs I can make you one up this weekend for 35 Euro + shipping.

  3. Hi,

    I dont belong to this field but i like to make some small hobby projects.In your schematic you didnt mentioned the voltage requirement for Vss & Vdd. Can you tell me wats the supply voltage requirement??

    • Hi Sirish,

      The circuit runs on 5 Volts but it has a linear voltage regulator on board so the voltage requirements are quite flexible.
      Anything from about 7 Volts up to around 30 Volts will be fine.


    • Hi Peter.
      I’ll dig around in my Eagle CAD archives and see if I can find them.
      [EDIT] I just realised that I already posted them online Here

  4. Hello catmacey, it’s Emmanuel from toulouse (FRANCE). Would you send me one charlieplexed circular PCB . What is you price and port for FRANCE.
    If you give me your IBAN, i would send you an account of the good price
    are you ok?
    Thanks a lot and merry Christmas

    • Hi Emmanuel.
      I’m sorry but I don’t have any left.
      It’s a very old project and I used up all my spares a while ago.
      The circuit is very simple. I’m sure you could build it on perf-board in an hour or two.
      Or you you wanted to get some made professionally my Eagle CAD files are available here

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