Holy smokes! Parallax is opening up a bit! CC schematic of propeller-based oscilloscope

Pt 2376
Pt 2377
We’ve hoped for a long time that Parallax would consider opening up a bit more – publishing schematics, some open source software here and there, you know – throw us an open bone. It appears the wait is over and Parallax is starting to put some things out there… Here’s a schematic for their “PropScope” – it’s creative commons (but the top left is a little weird, likely a template?)…

The PropScope is a two-channel oscilloscope that is capable of reading 25 million samples per second with ten bits of resolution over one, two, ten, or twenty volt peak-to-peak waveforms. Power is provided through the USB port requiring only a single cable to connect the PropScope to any laptop or desktop PC. A built-in expansion port allows additional capabilities and upgrades, by simply plugging in an expansion card. A PropScope DAC card is even included, providing an analog trigger, a four-bit digital trigger, an eight-bit digital to analog converter, and a four-bit NTSC/PAL output. Other cards will be available to add even more useful features. The included software provides a traditional scope interface along with auto measurements and the ability to store and export waveforms. The software also provides features not normally available in a stand-alone oscilloscope, including a function generator, a logic analyzer, a spectrum analyzer, a vector-scope, and more.

Great start, anyone from Parallax want to chime in to talk about what’s going on? You folks are so close! Release the firmware too!

Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards

Join Adafruit on Mastodon

Adafruit is on Mastodon, join in! adafruit.com/mastodon

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 36,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org

Maker Business — “Packaging” chips in the US

Wearables — Enclosures help fight body humidity in costumes

Electronics — Transformers: More than meets the eye!

Python for Microcontrollers — Python on Microcontrollers Newsletter: Silicon Labs introduces CircuitPython support, and more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Guardian Robot, Weather-wise Umbrella Stand, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — #NewProds 7/19/23 Feat. Adafruit Matrix Portal S3 CircuitPython Powered Internet Display!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


  1. Check out Ken Gracey’s post (#178) in this discussion:


    Ken is VP at Parallax.

    I’ve met several Parallax people (including Chip Gracey) at the UPENE meetings and they’re a bunch of great people who are very supportive of hobbyists.

  2. Hey there 🙂 We shall open up a LOT more in coming days. I’ll be sure to remove that note you found on the schematic about being “proprietary” so you can “have at it” with the design! As you noted, it’s available under Creative Commons. You’ll even be able to put an Arduino in the design should you desire! Thanks for the feature Adafruit! – Ken Gracey

  3. I’m really struggling with the perception that Parallax has taken a “closed” attitude with their products? Most of their books have and continue to be freely download-able. A complete library of code is freely download-able (MIT license), and most of their designs include code as well as schematics. Even their robots include complete piece specs if someone wanted to take the time to cut and design their own. I’ve been pleased to work with the folks at Parallax with the UPE expos the last couple years, and “closed” isn’t the word I’d use to describe them. All that being said, The Propscope is awesome and open. 🙂

  4. jeff, we def. agree that parallax does a great job in publishing information. in specific here we’re referring to publishing hardware/firmware/software under open source licenses which is a more formal method of granting users freedoms to the design (that is to say, less ambiguous than “hey email us and sure we’ll send you the code”).

    there is certainly code -examples- that are open source (which is certainty a good idea if one is selling a microcontroller that will go into products – in fact adafruit carries an osh kit called the ybox2 (designed by robert q) that could not have been done without the open objects in the propeller ‘library’) but we dont recall seeing a schematic, CAD files, or any core firmware that was specifically put out under an OS license before this.

    that said. we would greatly like to be proven wrong! if you know of any let us know! either way its still something to celebrate 🙂

  5. Understand your point ladyada. We can state it much more clearly, as you noted (who wants to send/answer the “e-mail us for source” messages anyway). Many files have been available directly on our web site, but sometimes it lacked clarity about their use with no OS license reference.

    Our source code falls is often placed under the MIT license (especially for the Propeller, which has a larger user contribution). What do you think of Creative Commons for the hardware side of open source?

  6. The PropScope and its Windows GUI look like really nice products! I bought a Link MSO-19 DSO this year and have found it invaluable for really seeing what’s happening with my circuits, but the documentation is essentially non-existent. The PropScope getting started PDF is clear and well-written. Anyone wanna buy an MSO-19? 🙂

    Now, how about a Mac-native GUI?

  7. ken, this is a topic with many opinions but not a lot of fantastic options 🙂 that said, we use CC SA-BY for our hardware schems/layout/CAD because the -intentions- are clear. Code varies as we may use other pieces of OSS which viral-y sets the license we use.

    There are also TAPR and Chumby Licenses, which are more patent-friendly.

    We tend to see others using CC or GPL for hardware as well, even if its not a ‘perfect fit’. I’m big on ‘honor system’ (which is what the legal system is anyways) and trust that when I say “attribution” people will figure out a good way to provide it.

  8. @blalor, we are just about to publish a document explaining the protocol between the PropScope and the PropScope GUI. This will enable people to write their own firmware or GUI quite easily, such as you requested for a Mac. I’m pretty certain we’ll see a Mac interface for the PropScope in a matter of days.

    To all, the PropScope schematic has been updated at http://www.parallax.com/Store/Microcontrollers/PropellerTools/tabid/143/ProductID/586/List/0/Default.aspx?SortField=ProductName,ProductName (scroll down) to clearly reflect the CREATIVE COMMONS license. Any references to proprietary information have been removed from the schematic, as shown at the top of this page. – Ken

  9. ken, you’re making me swoon! only little picky thing im going to follow up with is that with CC you kinda have to put down the ‘flavor’. What you had before “Creative Commons – Attribution v3” is perfect. If you don’t even want attribution you might as well put it under the public domain (just say ‘public domain’). Theres tons of info at the creative commons website.

    Great work, and if you have any other open source hardware/firmware please tell us and we’ll post it up!

  10. ladyada, right – the intent was Creative Commons – Attribution V 3.0. Guess I better start doing the PCB layout and schematic generation myself! I’ll see that we get that corrected on the schematic.

Sorry, the comment form is closed at this time.