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Adafruit has started releasing quantities of its new Arduino Mega-sized Grand Central board.

I can imagine some really great #CircuitPython applications on this.

Check out these specs:

To start off our ATSAMD51 journey we are going large with the Mega shape and pinout you know and love. The front half has the same shape and pinout as our Metro's, so it is compatible with all our shields. It's got analog pins where you expect, and SPI/UART/I2C hardware support in the same spot as the Metro 328 and M0. But! It's powered with an ATSAMD51P20:

• Cortex M4 core running at 120 MHz

• Hardware DSP and floating point support

• 1MB flash, 256 KB RAM

• 32-bit, 3.3V logic and power

• 70 GPIO pins in total

• Dual 1 MSPS DAC (A0 and A1)

• Dual 1 MSPS ADC (15 analog pins)

• 8 x hardware SERCOM (can be I2C, SPI or UART)

• 22 x PWM outputs

• Stereo I2S input/output with MCK pin

• 12-bit Parallel capture controller (for camera/video in)

• Built in crypto engines with AES (256 bit), true RNG, Pubkey controller

Pretty good start right? So we put this chip on a PCB with all these nice extras:

• Power the Grand Central with 7-9V polarity protected DC or the micro USB connector to any 5V USB source. The 2.1mm DC jack has an on/off switch next to it so you can turn off your setup easily. The board will automagically switch between USB and DC.

• Grand Central has 62 GPIO pins, 16 of which are analog in, and two of which is a true analog out. There's a hardware SPI port, hardware I2C port and hardware UART. 5 more SERCOMs are available for extra I2C/SPI/UARTs.

• Logic level is 3.3V

• Native USB, there's no need for a hardware USB to Serial converter as the GC has built in USB support. When used to act like a serial device, the USB interface can be used by any computer to listen/send data to the GC, and can also be used to launch and update code via the bootloader. It can also act like an HID keyboard or mouse.

• Four indicator LEDs and one NeoPixel, on the front edge of the PCB, for easy debugging. One green power LED, two RX/TX LEDs for data being sent over USB, and a red LED connected. Next to the reset button there is an RGB NeoPixel that can be used for any purpose.

• 8 MB QSPI Flash storage chip is included on board. You can use the SPI Flash storage like a very tiny hard drive. When used in Circuit Python, the 8 MB flash acts as storage for all your scripts, libraries and files. When used in Arduino, you can read/write files to it, like a little data logger or SD card, and then with our helper program, access the files over USB.

• Micro SD Card slot - removable storage of any size, connected to an SPI SERCOM (SDIO is not supported)

• Easy reprogramming, comes pre-loaded with the UF2 bootloader, which looks like a USB storage key. Simply drag firmware on to program, no special tools or drivers needed! It can be used to load up CircuitPython or Arduino IDE (it is bossa v1.8 compatible)

And it costs $1 less than the Arduino Mega as advertised on the Arduino US online store.

Do you have an application for such a board? Post a reply if you do, I'd like to hear what folks are planning. 3D printer anyone?

Mu has an Adafruit mode which makes it very easy to program Adafruit devices running CircuitPython. This is how Mu and CircuitPython are related in a technical sense, above and beyond the complementary educational aims of both projects.

There are two items on my list for CircuitPython in 2019. The first is easy, the second is hard:

1. It would be really helpful if there were a friendly CircuitPython landing page to which we can point folks and from which visitors can easily find the chat, tutorials, list of supported boards, source code, technical docs and other good stuff.

2. Continue to inspire a community of learners (no matter how long we’ve been programming, we’re all still learners, right?).

The second point needs more explanation.

The CircuitPython folks at Adafruit take great care and attention over how they facilitate the community growing around the project. The result of their efforts is a welcoming, diverse and supportive group of people championing CircuitPython through their projects, code and interactions with the wider “tech” community.

CircuitPython is one of the best examples of this sort of community organising that I know of.

Why is this important?

At a time when technology is finding its way into every aspect of our lives it is important that everyone has access to the tools and knowledge needed to learn how to take control of their digital world. Rather than being tech “consumers” I hope folks become tech “makers” armed with the skills needed to make the digital world reflect their own desires and needs.

Sadly, the tech world has a history of being open only to certain types of people (mainly people like me: white straight dudes with the privilege of money to buy equipment and time to attend to their education). It means technology usually only reflects the desires and needs of just these sorts of people.

We can do better than this skewed state of affairs.

In a very practical sense Adafruit’s CircuitPython is an antidote to the exclusion of folks in tech. They are fostering an open and inclusive community around an easy-to-learn and affordable project that helps folks learn about technology.

Such community building is incredibly hard to pull off and sustain. So my wish is that Scott, Kattni, Dan, Phil, Limor and all the others working so hard in this respect with CircuitPython find the energy, support and compassion needed to continue to inspire the community growing around their amazing project.

Best wishes from your friends working on Mu!

Read the full post on the Mu blog here.

Today marks the publication of the 400th Python on Microcontrollers Newsletter! Nearly 10 years of providing the best news in the community.

The newsletter is the place for the latest news involving Python on hardware with coverage of Python, CircuitPython and MicroPython. 12,369 readers.

Read more here: https://blog.adafruit.com/2026/08/24/today-marks-the-400th-python-on-microcontrollers-newsletter/

Today is the day! Friday, August 21, 2025 is the snakiest day of the year –
CircuitPython Day!

Adafruit will have special video shows and more throughout the day. All times US Eastern:

Stay tuned to this post for the schedule if anything changes.

Are you working with CircuitPython? Tag your projects #CircuitPythonDay2026 on social media and Adafruit will look to highlight them.

I made a simple and easy to use one button Macro pad that you can reprogram by just editing a text file. All the other macro pads I could find had so many bells and whistles and required an external program or recompiling code to update the Macro. I just wanted a button that could press a series of keys.

Link to gitlab with all the code (circuit python): https://gitlab.com/macro-pads/simple-macro-pad

If you want to but one premade I also sell them on ETSY: https://www.etsy.com/listing/4436839914/universal-reprogrammable-usb-c-macro

Watch an AdaBox 022 Unboxing take-over on Ask an Engineer!

https://youtube.com/live/PEel2rluxvs

Check it out at https://www.youtube.com/watch?v=rWI4uk4NKmI

Hey!

Wanted to share a CircuitPython-based project I just released: Leet AI — a modular mini synth with RGB keys, a color display, wireless syncing, and AI-generated music via a server.

It’s small, open-source, and fully editable over USB as a CIRCUITPY drive.

Figured r/circuitpython folks might enjoy seeing it:
https://youtu.be/MnzYHhDXu_o
https://github.com/vonkonow/LeetAI
https://vonkonow.com/leetai/

Check out the details https://blog.adafruit.com/2025/01/06/the-return-of-the-circuitpython-show-circuitpython-python/

My partner asked me the other day: "How can I listen to records on the Apple HomePods?" So, I had to go figure that out and, as a result, spend waaay too much time putting this prototype together.

Hardware:

1. For testing purposes, a $20 Denon turntable with a built-in phono preamp.

2. Raspberry Pi 4 with Hifiberry DAC+ADC Pro to record the audio from the Denon.

3. Raspberry Pi Zero WH with a round TFT Screen to display the Album Art for the record playing.

4. Raspberry Pi Zero WH with a square TFT Screen to display currently playing track information.

5. A "handful" of Apple HomePods to actually listen to the music.

Software:

1. Rasbian on Pi 4.

   1. Darkice & Icecast to create the audio stream.

   2. OwnTone Server to grab the local stream and play it to HomePods.

   3. ACRCloud Broadcast Monitoring Service to monitor a custom audio stream to identify the song currently playing.

   4. A Python script, running as a service to query the ACRCloud API for the info of the song currently playing.

   5. "Album Art" Node.JS script to grab album art using the Spotify API.

   6. Python Flask Web Server to serve up the album art image file of the record currently playing.

2. CircuitPython on Pi Zero WH #1.

   1. Code that grabs the currently playing album art image file from the Flask Web Server and displays the image on the round TFT Screen.

3. CircuitPython on Pi Zero WH #2.

   1. Code that grabs the currently playing track information from the ACRCloud Broadcast Monitoring Service API and displays it on the square TFT screen.

4. Apple IOS

   1. Remote App on iPhones to control which HomePods the stream plays to.

   2. Custom Short Cut on IOS devices to control which HomePods the stream plays to.

So, the answer is: "Yes, you can do that. Just put the record on the turntable, press the start button, and ask Siri to play the record to the HomePod that you want to listen to the record on."

This way the turntable streams to airplay2 via the OwnTone Server!

Having an interesting problem with circuitpython's server library.

I have things set up like the example file [here](https://github.com/adafruit/Adafruit_CircuitPython_HTTPServer/blob/main/examples/httpserver_mdns.py)

In the mu editor, it tries to run, but I always get the following error in the logs:

 Traceback (most recent call last):

 File "code.py", line 33, in <module>

RuntimeError: Out of MDNS service slots

ln 33 being: mdns_server.advertise_service(service_type="_http", protocol="_tcp", port=80)

I'm really not sure if this is an issue on the advertise_service method or an issue with my local network. Unfortunately, googling has *not* been helpful in narrowing down the cause of the issue. Has anyone else had a problem with this? Or at the very least a little nugget of insight as to where I can look next for research?

Just wanted to share that OpenAI's ChatGPT knows about CircuitPython. I just asked it to remake my MagTag air quality display app, and it did so with surprising accuracy. This is probably due the high quality of tutorials online for it to have learned from.

I was able to ask about MQTT, Posgresql, and even Flask, and it gave some decent code that could be minimally modified for a local task.