The DigiRule

By brad, October 8, 2015

Digirules are available again from my Tindie store:

Here’s a youtube video of the improved version:

And now back to the original post…

This project is completely open source. You can download all files including PCB layout, source code and BOM in the link at the bottom of this page.

UPDATE: 30 December 2015 – Jaap has made a really cool DigiRule Java Simulator which you can check out in the link below. Try the DigiRule without having a DigiRule!

DigiRule Java Simulator

I’ve seen a number of PCB rulers out there for example this one from Adafruit:

However I wanted to make one that was a little more interesting and of course, should have some LED’s built in. (LED’s seem to make electronic projects more interesting…)

So I made the DigiRule! – The DigiRule is a 15cm (6″) ruler with which is marked in binary digits rather than decimal. It has a number of built in digital functions including:

  • Logic Gates
    • NOT Gate (Inverter)
    • OR Gate
    • AND Gate
    • XOR Gate
    • NOR Gate
    • NAND Gate
    • XNOR Gate
  • Flip Flops
    • SR Flip Flop
    • JK Flip Flop
    • Toggle Flip Flop
    • Data Flip Flop
  • Four bit binary up/down counter

It is powered by a single 3V CR1220 button battery and the brains of the unit is a PIC 18F43K20 microcontroller (which is a greatly over powered device for such a simple task – but they are cheap!)  The functions listed above are controlled by nine surface mount push buttons and has twenty three surface mount LED’s to show the status of the inputs and outputs.


The rear of the ruler contains logic gate and flip flop truth tables, a binary conversion chart, a few select SMD component footprints and some drill hole sizes.



Check out the youtube video for a demonstration:

Here is the ICSP (In Circuit Serial Programming) port connector pinout.

Screen Shot 2015-12-16 at 10.16.17 am

Click below to download the DigiRule archive – note this contains all software fixes for the button bounce issue and the SR flip flop issue. It also contains a simple user manual to help with using the DigiRule. (Note, there seems to be an issue with Diptrace not importing the silkscreen images so I have included these in the latest download for if you want to modify it at all within Diptrace)


Additional (free) software to go with the above download include:

Diptrace – The PCB editor that I used to design the DigiRule

Swordfish Basic – The IDE that I used to code the DigiRule

PICKIT2 Software – The software that I use to transfer the .hex file to the DigiRule’s microcontroller

And finally, a PICKIT2 (or similar) USB programmer to actually copy the .hex file to the microcontroller (this is used in conjunction with the PICKIT2 Software). You can buy a genuine PICKIT2 or 3 from or you can buy a clone for cheaper. Since microchip has released the PICKIT2 hardware and firmware as open source, there is no problem with buying a clone. I recommend this one:





  • Bitfogav

    Neat little project Brad, I like how you’ve added logic gates into the ruler. Will we be able to get one of these?! 🙂

  • Pedro

    When can I get one of these awesome rullers? 😀

  • Ian

    That is without a doubt the coolest ruler I have ever seen. You left out the blinking LED.
    Do I see a Kickstarter project on the horizon…..

  • admin

    Hi Guys – thanks for the comments!

    I was going to do a Kickstarter campaign but it looks like they will be a bit expensive when you factor in fees and shipping. They would probably cost $15 each all up which is perhaps a bit expensive for a ruler 🙂

    • Ian

      I would be more than happy to pay $15 for one of these. I bought two of your digipixel modules from your last Kickstarter and they were nothing short of excellent, so based on that these rulers should be good value for money, sure the Adfruit ruler is about $5 but all you can do with that is draw straight lines, yours is so much more that a ruler….

  • Matt

    I would gladly pay $15 for this.

  • Bitfogav

    I would be more than happy with the $15 too..

  • I agree — I would happily pay $15 for one of these little beauties!!!

  • Roeland K

    yup would buy this if shipping to EU wasn’t ridiculous 🙂

    Any chance on making the design open?

  • admin

    Roeland, I don’t know why I didn’t upload all the files for this project! My mistake, I have now uploaded an archive containing all files needed to make and modify your own DigiRule!

    As for a Kickstarter campaign, I guess I’ll look into how cheap I can get them made for. Let me see what I can figure out 🙂

  • Bitfogav

    Could you not cut the cost down by using a PIC with fewer pins? and maybe remove the On/Off switch and use the PIC sleep mode to save battery? just an idea 😕 I would love for this ruler to have a USB connection (but obviously those PIC’s cost a few more $)..

  • Ian

    $15 shipped? Sign me up too. Only 995 more comments like this and you don’t even need Kickstarter. Though I’d be curious to see what kind of stretch goals you could come up with.

    I say give it a shot, worst that could happen is you actually have to manufacture and ship a bunch of rulers 🙂

  • Gary

    Awesome gadget!

    I’d also happily pay $15 for one of these – so long as shipping to AU wasn’t a million bucks! 🙂

  • I’m not a PIC guy. What do I need to program the micro?

  • admin

    Gary – the $15 I quoted would be all inclusive I.E. that would cover the cost of the DigiRule, Kickstarter and Amazon fees and also worldwide shipping. Since there is a bit of interest here and on youtube, I will certainly see if I can get them made for $15 all up (or under that ideally) – if I can, I will run a kickstarter campaign.

    • Pedro

      Can’t wait to see it up on Kickstarter!

    • Ian

      Best news I’ve heard all day. I’m gonna get me a best nerd ruler ever invented!

  • admin

    James – To program PIC’s you would need some sort of USB programmer (or you could go old school and get a parallel port programmer).

    I use a PICKIT 2 which is designed by microchip but is open source so you can pick up a third party one from ebay or aliexpress etc… for less than $10. Like this one,201527_4_71_72_73_74_75,201560_9

    You then need the pickit 2 software (which is free) from here:

    You then connect five wires from the PICKIT 2 to the PIC microcontroller (GND, VCC, VPP, PGC and PGD) open up the hex file (in the download on the digirule page) and copy it to the PIC.

    I hope that helps!

  • Awesome, thanks Brad for the mini-tutorial! 😉

  • David

    Count me in for $15 it’s a cool no-brainer!

    It could make a useful small gift for kids or anyone getting into micro controllers to begin delving into the world of digital electronics.

  • Bitfogav

    Hi Brad, I’m guessing if this do go to a kickstarter, that there will be a ICSP connector added to the board? 🙂

    • If this trend is as wide spread as it seems from the reports, it make me wonder how it will eventually affect China or any other totalitarian ruled country that refuses to allow its citizens to communicate openly with other societies throughout the world. If China currently prohibits access to many areas in cyberspace, how will one of the leading manufacturers and exporter of goods keep up with industry as other countries become more close knit or innpedreetdent? Will they have eventually yield to the winds of technological change? If you believe in ancient prophecy, the answer to that question is, yes.

  • Daniel Richert

    Im in for the kickstarter. this is awesome.

  • RÖB

    This was just featured in so get ready for plenty of interest!

  • Fer Uria

    Worldwide shipping sounds great to me, Ill be glad to buy one.

  • brian

    yes its a winner of an idea put me down for one ,needs LEDs of course

  • Patrick

    Please do a Kickstarter!
    I really would like to buy one!

  • Getting subscribed to the comments so I can join any crowdfunded project that happens.

    I bet a lot of the people who backed would be interested too…

    • Ian

      At least one of those people who backed the Chip on Kickstarter is interested in this 😉

  • EricJ

    Are you kidding? OF COURSE I would pay $15 for a couple of these. I congratulate you on the nerdiest ruler I have ever seen! They would make great gifts for geeky friends and family, I would surely be ordering 4 or 5 as gifts.

    Count me in!

  • It looks so awesome. I would pay $15 and more for this ruler. In Germany I have to pay 4-5€ for a ruler. And this one is so much better! It will be the rescue in every boring lesson.
    Please start a kickstarter campaign.

  • lol123tm

    If you make a kickstarter i would buy one or two.

  • lImbus

    shut up and take my money !

  • DrSommer

    !Please, please, please!
    let us crowd-fund it
    I’ll take two

  • I’ve shared it two times on twitter, but the counter doesn’t react. 🙁 I hope that is no reason for giving up the kickstarter campaign!

  • Eric

    Count me in. 15$ is absolutly fine.

  • Andy

    I’d buy 2

  • Fotis Τ.

    I really would like to buy 2-3!


  • Peter

    Would definitely pay 15$ for DigiRule. Do you know ? I think they could be interested in your DigiRule too.

  • Benjamin

    I’ll buy two of them if you’d ship them to germany!

    Do it!

  • Thomas

    Count me in for the Kickstarter project :). Thanks a million from Ireland!

  • Bernhard

    Congratulations for this cool project! Count me in for two of them, I will gladly pay $15.

  • Dieter

    I’ll buy two of them too if you’d ship them to germany!

  • Carsten

    I would buy ten at least. I have so many nerdy friends out there which would kill for those ones.

  • Stefan

    Count me in, I would also take 2-3. Greetings from another german nerd 😛

  • Achim

    Great little nerdy tool! I would buy three of them, shipping to EU / germany please.

  • Oliver

    Want it!

  • Alex

    I would buy also two if you would ship them to Germany! Great gaged!

  • maker

    This is awesome! Make sure to add some stretch goals cause this is gonna sell like crazy. How about a 30cm version? A 7-segment counter? A built-in LED-based pong game!

  • Bitfogav

    How about A led matrix like the USB Meter Pro 5×10 pixel leds.. 🙂

  • Philip

    You definitly need a branch Office in Germany. I’d be great to by at least one.

  • chr.kropp

    want to have atleast 2 pieces

  • Sylvia

    I am interested in 2 pieces, too. Is it possible to buy them via Amazon?

  • Volker

    I would buy also such a rule if you would ship them to Germany! Great gadged!

  • Jens Mademann

    Nice gadged for sure! If you ship to Germany as well, please count me in.

  • Björn

    Nope, 15 Bucks for this nice piece of hardware-ruler is fine by me 🙂
    Looking forward to your kickstarter campaign!

  • Birdie

    Also as Jens wrote: If you ship to Germany pls. let me know.

  • Peter

    Very cool stuff!!
    I would buy up to 10 instantly for 15$ to 20$ each. Same for me as the other wrote -> great present for my geek friends and for me!!
    Perhaps they can help if Kickstarter is to big or expensive:

    maybe would Support this Project in some way.

    Go, go! great idea!!

  • Yves

    That would be a great Christmas present for a few friends of mine. I think I would take 2 or 3, if you ship to Germany. ^_^

  • Superb idea – consider the PIC32MX250F128B in the SMD package. It has USB onboard, so you could add a micro port. It is programmable via MPIDE or UECIDE similar and compatible with Arduino IDE. I can help you with the bootloader …
    Anyway – 15$ for this ruler is perfectly ok for me – looking forward to the campaign
    Ciao, Mathias

  • Schallrich

    Count me in, I would also take 2-3.

  • sascha

    whooaaa. this is just brilliant!

    so, me too ™! i would take 2-3 depending on the shiping costs to germany.

  • Bernd

    Now I finally know what I want to buy as a christmas gift.
    I’ve got quiet alot of friends who are interested in this ruler.
    Make sure to ship to Germany 😉

    Also thanks for the archive, I’ll definitely try to build this ruler on my own.


  • MS


  • janhoo

    same with me. count me in for at least two.

  • Markus

    Count me in! This is great!

  • Alan

    Real great idea, even being in europe I would definately buy at least one!

  • Markus

    Count me in for at least two of these gems if you start a kickstarter campaign!

  • Tobias

    … where is that KickStarter link, again? 15US$ + shipping is ok.

  • ressl

    I’m highly interested, but Be careful with the name and copyright! There exists a company with this name…

  • Marcus


    great project.

    I would buy it at 15$ + shipping.

    • yusuf kurtuluÅŸ diyor ki:slm iÅŸ bilenin kılıç kuÅŸananın senelerdir yurt dışındayım yüksel inÅŸahatı çalışmaların dan ve baÅŸarıların dan dolayı yürekten ve can dan kutluyorum bir türk olarak ta gurur duyuyorum saa8ılyrımla&#g230;

  • Adij

    I d be willing to get one as well for 15$ and shipping , maybe even two or three, for the right people it s also an awesome gift 😉

  • Tom

    Hello, great Idea… please metric scale and CR2032 (BIOS battery) so you can get cheap replacement. Maybe a blinking LED or a POV-Mode, when you move it fast?

  • Andy

    The metric scale is on the DigiRule already (in binary). a CR2032 is too big and too thick. No point using a bigger battery.

    wtf, a blinking LED and adding more components?? I think you didn’t get the idea about this thing…

  • This ruler is THE Nerd xmas present I have been looking for. 15 usd is absolutly fine … I would pick 3 and shipping to Europe (yes, we also have nerds).

  • OK

    Do it — Kickstarter!!!!

  • DeeKay

    Please do it, on Kickstarter or any other way.
    For 15 bucks I would buy 3 of them. But please please please, do a cheap shipment to Germany / Europe.
    Would be so great, I like this design so much!!

  • Alex Schmidt

    I wanna buy one or two! Perfect for christmas. Grettings from Germany.

  • Muschelschubser

    Aweseome! Count me in, I would buy one or two.

  • Winni

    Where great Job!!
    I wonna buy two DigiRules. Please do it before Chrismas.

  • Henning

    I want some !!! 3-5 i think!!!!

  • Simon

    I definitely have to buy 3 of those. Where to get it?

  • Mike

    Need it! Please do it!!!

  • Another Stefan

    I would also take 2-3.
    Please do it before Chrismas (shipment to Germany).
    Greetings from another german nerd.

  • Michael

    I like to buy a DigiRule + shipping to germany. Is there a KickStarter project available now?


  • Clemens

    I would also take one (or two 🙂

  • admin

    Thanks for the comments everyone, I have just submitted the project to Kickstarter and i’m just waiting for the approval from them. As soon as the approval comes through, the project will be live. I have updated to the DigiRule page on my site (above) with the details.

  • Roland

    I would also take some of that rulers – great idea! Hopefully shipping to germany shhould be no problem?

  • Thorsten

    15 $ + shipping to Germany.. That is a great deal 🙂 Hope the kickstarter start quickly and it is done before Xmas. Greets from Germany

  • Great toy, Would love to spend 15 $ + shipment to Germany!

  • Thomas

    Want it. WANT IT!

    Even more then one, it’s a usefull gift for some of my freinds too.

    Waiting for the Kickstarter page to open!

    How much is shipment to germany?

  • Björn


    thats great, i want it too! please tell me wehre i can spend some money, and tell us the shipment to other countrys (Germany).

    this is a great idea

    greets from germany 🙂

  • DeeKay

    Very nice, that you listened to us and made a Kickstarter project for it. They must approve it, it’s just a very smart idea. And – as I wrote on Kickstarter – one of the coolest gadgets I’ve seen for a long time. I know some people, who want this if they see the ruler on my desk. A great gift for nerdy friends. So the 5-pack is mine. 🙂

  • RÖB

    If there is going to be a version 2.0 … Can I suggest that you use a LIR2032 recessed onto a large hole in the PCB and a printed USB plug just to recharge it.

    CR1220 40mAh 3.0V – non-rechargeable
    LIR2016 12mAh 3.6V – rechargeable
    LIR2032 45mAh 3.6V – rechargeable

  • Rudi

    count me in for 5 units on kickstarter!

  • Pedro

    Project is now live! And I was the first to pleadge!!! \m/

  • admin

    Okay everyone, here we go – the Kickstarter campaign is now live! Here’s the link:

    • IAN

      Two and a half hours after launch and your kickstarter is funded….. That must be some kind of record

  • admin

    Thanks again for all the comments guys. I think I may have to start thinking about the DigiRule 2, there have been some great suggestions coming in 🙂

    Congratulations to Pedro for being the first backer!

    I have included worldwide shipping costs in the price of each reward on Kickstarter, so no matter where you live in the world, there is no more to pay other than the reward price that you have chosen 🙂

    And let me say a big hello to all those from Germany – I’ve had loads of comments from you guys! thanks for your support 🙂

  • Clemens

    Thanks for starting the campaign!

    Oh no, no second version, i would have to buy it too and then my desk would be full of rulers 😉

    Greetings from germany!

  • DeeKay

    Oh yeah, at a second version of the DigiRuler, 30cm maybe, I have to buy it, too. What shall I do with all this rulers, man? 😀
    And I’m only one of the 20th backers, the Kickstarter page was hanging… I’m sure because of your project. 🙂 But I’m glad for my five rulers.
    The webpage made some kind of good advertising for you…^^
    Now – as you expect – greetings from Germany!

  • Freddi

    Ordered 5, I just hope they will make it in time for christmas. Also a little worried about customs …

    Anayway, greetings from Germany and I hope to see “DigiRule2 – The second coming” happening next year 🙂

  • Peter

    Thank you very much, that you kickstarted it!!
    I ordered 10 and I’m looking forward to Digirule2 😉
    Would be great, if you collect ideas for version 2 from your backers.

    Kind regards

  • Thomas

    How’s about adding kinda Flashlight… every now and then some random light patterns show up on the LED’s and vanish a second later or something like that.

    I just want to see how long it takes until my Boss gets irritated at his meetings 🙂

    Kind regards

  • Bradley,

    Please make the inches graduations in 1/16th intervals. Anything else would make it not as useful.

    Thank You,


  • RÖB

    Please don’t change the 1/10 inch scale to 1/16 inch. It’s a logic / PCB ruler and in the PCB world *all* imperial measurements are in 1/10 Inch.

    I have ordered one. I like the LED’s and switches and it’s geeky and I can show it off lol but I learnt these things decades ago. As for actually using it well I will have it on my desk for measuring component dimensions so 1/16 inch is useless. I currentlt have a offcut of vero board that I use for imperial but I have to count the holes.

  • RÖB

    I don’t understand why your changing the ruler measurement markings.

    You now have the ‘direction of print’ opposite to normal. Dimensions are usually read from the far edge of the ruler as what you’re measuring can larger and higher than the ruler and can obscure your vision of the rule if you use the closer edger to measure.

    Have a look at a ‘normal’ ruler. ie even if you reverse the ‘count direction of dimensions’, the ‘direction of print’ will remain the same.

    At the moment ( you have both the ‘count direction of dimensions’ AND the ‘direction of print’ backwards for both inches and cm when compared to a normal ruler.

  • admin

    @RÖB – you are exactly right – however I realised my mistake in my update, fixed it and then changed the update to reflect the change. However the details in the email you would have received would still have been the incorrect information.

    Have a look at the modified update on Kickstarter and you’ll see that it’s all been fixed 🙂

    I hope that helps!

  • RÖB

    That’s perfect!

  • Hi Brad-
    My colleagues & I here at Microchip spotted your project, and we all think it’s an awesome tool! We’d love to see the logic functions done in hardware with the Configurable Logic Cell on our newer MCUs if you decide to do a Version 2.0! Even if you don’t plan any updates to the DigiRule, we’d like to be a part of your next project. Can you send us your contact information? Just drop us an email with your contact info at


  • Karsten

    Another awesome project!
    Which, again, I learned about too late,

    Because: it is already SOLD OUT, even with over 1 hr to go.
    So my question is: Will there be a 2nd run?
    or: are there more than those in the kickstarter-campain?

    (I have a track-record of seeing Brads project too late…)

  • ressl

    why only 10 days? I missed it completely (2 days) 🙁

  • Karsten

    Quote Brad (from the kickstarter page):
    “I have allowed about 50 extra DigiRules just in case some people receive a faulty one, I can send a replacement out to you.”

    No guessing what i am about to ask?
    The 10-day-deadline got me, so if, after all eventually faulty ones are replaced and you might have some still left over, please contact me.
    Thanks a million!

  • Joerg


    could you please update the link to the DigiRule Files from Oct. 10 on this page with the new eight modes version from Kickstarter.

    Many thanks

  • matt

    I just saw this today and missed the kickstarter. Is there any way we can purchase one outside of the kickstarter campaign? Would be great to teach my kids.

  • admin

    Hi Matt, unfortunately I am making just enough for the kickstarter rewards at the moment but if I do have some to sell after all of those are gone, then I will upload details to this page 🙂

  • admin

    Hi Joerg, I’ll see about posting the new version code in the next couple of days 🙂 I have to admit it was not coded very well, but it does the job!

  • James

    Now that the Kickstarter has ended, is it still possible to get one. They look really cool! I would also happily pay for the PCB schematic, code and similar things to make one myself! Great project!

  • Joerg

    “DigiRule Files 03 December 2015” Many thanks!

  • Peter

    the rulers just arrived! I’m happy to have them before christmas! Thank you very much! Just one question: Is there somewhere a written manual? It is not really necessary, I just thought it would be nice to have something printed when I give them away as present.

    Thank you very much!

  • Peter

    Hi Brad,

    forget everything about the “manual”. I didn’t think about the manual on the back of the ruler – this is more than enough! It’s a geek tool, for a real geek the buttons should be enough 😉

    Thank’s a lot for the delivery before christmas!

  • Strongground

    Okay, so I guess there is no way to purchase one of these anymore?
    A shame that.

  • Victor


    I was trying to update the firmware.
    I was using ICD3 and IPE, but here’s my output…

    I try to use IPE here’s the output:
    2015-12-10T00:20:54+0800- Completed loading IPE.
    2015-12-10T00:21:20+0800- Loading hex file. Please wait…
    Loading code from F:\Hobby\DigiRule\DigiRule-18F43K20-Modified-06-Dec-2015\DigiRule 18F43K20 Modified 06 Dec 2015.HEX…
    Warning: F:\Hobby\DigiRule\DigiRule-18F43K20-Modified-06-Dec-2015\DigiRule 18F43K20 Modified 06 Dec 2015.HEX contains code that is located at addresses that do not exist on the 11AA010.
    Code incompletely loaded.
    Warning: F:\Hobby\DigiRule\DigiRule-18F43K20-Modified-06-Dec-2015\DigiRule 18F43K20 Modified 06 Dec 2015.HEX contains code that is located at addresses that do not exist on the 11AA010.
    Code incompletely loaded.
    2015-12-10T00:21:20+0800- Hex file loaded successfully.
    Connecting to MPLAB ICD 3…
    Currently loaded firmware on ICD 3
    Firmware Suite Version…..01.40.05
    Firmware type…………..PIC18F
    Target device was not found (could not detect target voltage VDD). You must connect to a target device to use ICD3.

    Got any ideas?

  • Victor

    2015-12-10T12:36:14+0800- Completed loading IPE.

    2015-12-10T12:36:22+0800- Loading hex file. Please wait…
    Loading code from G:\Hobby\DigiRule\DigiRule-18F43K20-Modified-06-Dec-2015\PIC18F43K20.HEX…
    2015-12-10T12:36:23+0800- Hex file loaded successfully.


    Connecting to MPLAB ICD 3…

    Currently loaded firmware on ICD 3
    Firmware Suite Version…..01.40.05
    Firmware type…………..PIC18F

    Target device was not found (could not detect target voltage VDD). You must connect to a target device to use ICD3.
    2015-12-10T12:36:46+0800- Programming…


    Connecting to MPLAB ICD 3…

    Currently loaded firmware on ICD 3
    Firmware Suite Version…..01.40.05
    Firmware type…………..PIC18F

    Target device was not found (could not detect target voltage VDD). You must connect to a target device to use ICD3.
    2015-12-10T12:36:52+0800- Programming failed
    Pass Count: 0

  • Bitfogav

    @Victor I’ve not got a ICD3 but you’re ICD is saying quote”Target device was not found (could not detect target voltage VDD). You must connect to a target device to use ICD3.”
    It sounds to me like the device needs to be powered before the ICD will upload the code. Have you tried powering up the Digirule with the onboard battery and switch in the ON position? and programming with ICD?


  • Victor

    Hello Gav,

    I was afraid the battery will short to the ICD3 or something….
    Do you have sch of the digirule?

  • Victor

    Hey Gav,

    Thanks for the tip, I put the battery and was able to update, no more bounce after.



  • RÖB

    Until I received the DigiRule, I thought I has every size of button cell. lol.

  • Bitfogav

    @Victor – That’s great, glad my tip worked. I’m not sure there is a Schematic for the Digirule, that would be up to Brad and whether he has one or not?.

    If there is any questions with the Digirule then you can always ask or leave a topic post on the Digirule forum here:

  • admin

    Sorry for the late reply here guys!

    I actually don’t have a schematic to be honest – I designed the DigiRule straight onto a PCB layout. However the schematic would be simple to come up with, just have a look at the sourcecode (which you can download above) and it declares all input and output pins. For instance it will tell you that PORTA pin0 connects to a specific LED or a specific Button. The only other thing really is that you need an 820 ohm resistor in series with each LED and then a 10K pullup resistor.

    I will also be looking to make a nice little PDF that you guys can download with some simple instructions for all of the functions.

  • RÖB

    I get a message “this file has an unspecified security flaw” when I try to open

  • Tom Johnson

    Thank you for all the hard work you put into this project! I just finished reprogramming my son’s DigiRule with my PICkit 3. I used your latest build but replaced the smiley face POV message with my son’s name. I can’t wait to see his face when he waves it in the air and sees his floating name! Thanks again…

  • RÖB

    What would help the most for re-programming are –

    A pinout of the JTAG port in a common image format so that I don’t have to figure it out from Gerbers when I don’t have a Gerber viewer or the right PCB CAD on my computer.

    The zip files with new code in a zip that works on windows so that I don’t have to install a complex unzip package to get to the files OR even the code – unzipped – it can’t be that big! If I can download videos then I can download anything that can fit in a PIC.

    To be clear – I am very happy with the DigiRule but I am just reloading my system and don’t have PCB CAD / FPGA / Micro-controller IDE’s etc yet so I am probably were other non-coders are. Just a code reload shouldn’t take a PCB CAD and a specialised Zip tool for an *average* user. Some instructions would probably help the inexperienced.

    I could help with any of these except the instructions. I have a K150 programmer that I am going to try to see if it works. If someone has one of these then they probably don’t need any instructions.

  • Robert Ralston

    Wiring questions

    a. Are there 10k pulldown resistors on all the pins connected to buttons? So when the button is pressed, it connects Vcc to the input pin?

    b. PORTB.0 is not assigned to either buttons or LEDs and yet it is configured as an output. Is this to minimize current consumption?

  • I have written my own update of the software. The main additions are that in mode 7 you can change the 6-sided changed die into a die with any number of sides from 2 to 31, and there is an additional mode 10 which is a tricky puzzle game. You can download it from my site here:
    Feel free to use it however you like.

  • your time. You simply can’t exepct to be productive if you can’t manage your time effectively.Success in both business and personal undertakings will often be traced back to how really good your quire some assistance in how to manage your time more efficiently? What do you do? ManicTime is a

  • Robert Ralston

    Although the code is adamant about turning the brown-out reset enable off (“Config boren = off ‘ this is a must if using coin cell batteries! the micro controller always resets itself …”), I’m not finding this to be true.

    I’ve set the BORV to 1.8 volts (using the Configuration Word editor in the standalone PICKIT2 application rather than a config statement)

    So far, so good, no resets observed in any mode (battery measuring 2.5 volts with 4 LEDs on).

    With a short LED flashing sequence on power up, then presumably the ruler would start doing this flashing sequence when the battery got low, acting as a “low battery indicator”.

    I’m going to put my remaining ruler on a power supply and slowly crank the voltage down to view what happens but those results might vary with a coin cell so I’ll keep watching the coin cell behavior.

  • Sascha

    I’ve built a C version of your firmware with some enhancements. Maybe you’ll like it:

    Thank you for that cool project.

  • Peter

    Hi Brad,

    again thanks a lot for this great gadget. Most of the 10 i bought are gone as presents for christmas.
    It would be great to have a possibility to get some more. Do you intend to offer a 2. batch? I’m quite shure another 1000 pieces would be sold out very quickly.

    What do you think?
    Kind regards


  • brad

    Hi Peter, I have a batch of 200 coming soon. I have made a few improvements to them by updating the firmware, changed the battery to CR2032 and also fixed the messy fonts on the reverse side of the ruler 🙂 I’ll let everyone know when they are ready to go. If they sell out quickly then I’ll just get another batch made.

    • Tom Johnson

      I bought two from the first round. Count me in for 4 if possible… Thanks!


  • matt garrison

    How would we be able to purchase the 2nd batch? Through this site or another avenue. You can count me in for 2

  • Peter

    Count me in for another 10!


  • Karsten

    Two for me, please, and i didn’t get any from the first batch,
    so do I get first pick? 😉

  • Stefan

    would love to have also 10 of these!
    Please add me to the list

  • I would also like another 2 of them.

  • Robert Ralston

    Five more for me please.

    And, a BIG thank you to Sascha for rewriting the code in C.

  • brad

    Hi again guys, I have now added a DigiRule pre-order option on top of this page. I will be taking pre-orders throughout February 2016, with the aim to ship late March or if not then, early April. Thanks for your support with the DigiRule!

  • Wolfgang

    Is there any chance to pay via PayPal?
    I do not want leave my credit card details (inkl. security number)

    kindly regards

  • Karsten

    I was showing your Digiruel to some friends to order together
    and wanted to place our (pre-)oder,
    but the button is gone, does that mean they are out again?

    Or did you pull the preoder-page to be replaced with the yet-to-come shop?

  • Michiel

    Hi Brad,

    I pre-ordered on February 5th (lucky me) but did not receive a confirmation or so.

    Well you send out confirmations?

    Best regards!

  • brad

    Sorry for the late reply Karsten (and the not so late reply to Michiel).

    @Karsten – I have had quite a number of pre-orders and so I wanted to just cut that off for the moment, and get those all sorted. Then I will be able to sell some on my electronics store that I am soon opening up. I’ll certainly let you know when that happens!

    @Michiel – You should have received a confirmation email of some sort after the payment was processed. Did you not get anything at all? Or are you referring to a confirmation from There wouldn’t be (and won’t be) a confirmation from but you will get another email from the payment processor that I use ( once I have shipped them off. In fact that is going to happen a lot earlier than first thought. They will be ready to send within a week!

  • Hi,

    very cool project.

    One idea: wouldn´t it be better for the “led shake display” to rotate the leds in 90°? Then you can just swing the ruler like a pendulum with just two fingers. This would be more easy and fast to handle instead of moving the hole ruler including your hand and arm from left/right.

    Best Daniel

  • I got my two DigiRule 2’s yesterday. I still have to get batteries, but they do look good. Thanks!

  • Murdoc

    Hi Brad,

    You go you generate the POV Message? In particular the “Const POVMessage”.

  • Margaret Leber

    I’m up for two also.

  • Gary

    Hi Brad,

    How’s the new store coming along?

    I’m busting to get my hands on a couple of these!


  • RocWe

    Hello Brad,

    for one year now I try to get a nice DigiRule 🙂 . But I am always too late 🙁 (pr-orderbutton gone, shop closed .. ).
    Is it possible to contact me, for the price including tax an shipping to germany.

    Please 🙂

  • Much thanks! It is definitely an great online site!.

  • Jeff Luban

    Do you plan to sell the DigiRule again? It is super cool.

  • Hi!

    Did you have this produced?

    If yes, please contact me.

    Thank you.

  • Sean Donnellan

    Hi Brad,
    Will there be another batch of digirules? I’d gladly buy a few as the one I have from the kickstarter is great and there are plenty of people who would like one.

    Great project and my hat is off to you for it.

    • Brad Slattery

      Hi Sean, I have had a number of people ask for some more Digirules so I am getting a batch of 100 made up and will post them up for sale on Tindie once they are all ready to go. Here is my Tindie store:

      • Alfredo Linguini

        Do you have an estimate of how much time will it take?

        • Brad Slattery

          Hi Alfredo, i have just had word from the factory and they will be ready to go this week. I will be posting them up for sale on Tindie in the next day or two.

          • Hannes Fischer

            How much are there available on tindie?

          • Brad Slattery

            Hi Hannes, there are 59 left in stock on Tindie.

          • Hannes Fischer

            Thanks. I found it out myself yesterday and ordered one almost instantly. This ruler is amazing 😀 Greetings from Germany 🙂

  • Jacoburge

    Hi Brad,
    Just looking at the PCB file, it seems to be missing a file that provides all the tables on the bottom silkscreen (it comes up with just a white square)? Will you be making your update open source? Thanks!

    • Brad Slattery

      Hi Jacoburge, I have just uploaded the updated version however even in the old version I had no problem with viewing the bottom silkscreen in my Gerber viewer. In any case, give the new version a download. It is dated 02 July 2017.

      • Jacoburge

        Hi Brad,
        Thanks for uploading those files. I am viewing it in diptrace and still cant see most of the bottom silk as well as the logo on the top silk. Is it an image that’s stored away from this directory?

        • Gavin W

          Hi Brad I have tried the updated file and can also confirm the bottom silk logo is missing.. This must have been an imported image of some kind which doesn’t get transferred from computer to computer, even by coping the project, this is a bug with Diptrace.. A fix would be to supply the image and the end user re-apply the image in Diptrace. Thanks Bitfogav

          • Brad Slattery

            Thanks Gav, I’ll have to remember this little bug for next time!

          • Gavin W

            Update – Originally I thought this was a bug in Diptrace, because this is what I’ve experienced before but what it now looks like is that the image files created by Diptrace ending .dipb1 .dipb2 are missing from the upload. I’m sure Brad will update the upload file soon 🙂

          • Brad Slattery

            Alrighty it’s all fixed 🙂 Thanks for the help with this one Gav, I should pay more attention next time to the files that Diptrace generates!

        • Brad Slattery

          Hmm, I see!

          I’ve updated the zip file again and have included the top and bottom silkscreen images. It seems strange that Diptrace wouldn’t save the file in a format which includes the images automatically. I hope this helps now though 🙂