Recreating a calculator pen with SAMD21 and #CircuitPython @josecastillo @Microchipmakes

Recently, Adafruit posted about the calcu-pen, a retro piece of technology.

Maker Joey Castillo really liked the concept and decided to make a more modern equivalent. He’s using a SAMD21 microcontroller and technology developed in prior projects like a crowdfunded watch. Custom PCBs from Oshpark.

Joey says:

Y’all.Great success. First off: the pen is a pen. No battery as of yet, but that’s not much weight; so far it feels balanced in the hand, and size-wise feels reasonably in line with other pens in my arsenal.

But second and more importantly: IT WORKS! And runs Python, because that’s another joy of using the SAM D21 for prototyping: CircuitPython always “just works”.

I just wrote a simple calculator app for the pen in CircuitPython and broke into the most over the top gigglefest. like I cannot explain why this is so hilarious to me but it’s been five minutes, I went to fetch my camera and I’m still laughing, it’s so ridiculous

See the results so far below and read the entire design process in this Twitter Thread.

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, 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.

Join 35,000+ makers on Adafruit’s Discord channels and be part of the community!

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!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more

CircuitPython – The easiest way to program microcontrollers –

Maker Business — Chip inventories rise as demand falls

Wearables — How to attach a battery to your next wearables project

Electronics — Check out this shorthand shortcut

Python for Microcontrollers — Python on Microcontrollers Newsletter: 400 CircuitPython Libraries, 3m Thanks and much more! #CircuitPython #Python @ThePSF @micropython @Raspberry_Pi

Adafruit IoT Monthly — 2022 in Recap!

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! — JP’s Product Pick of the Week 1/24/23 IoT Button BFF w NeoPixel for QT Py @adafruit @johnedgarpark #adafruit #newproductpick

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

No Comments

No comments yet.

Sorry, the comment form is closed at this time.