Feather M0 Sine Wave generator using ZeroDMA #Adafruit #Feather #ZeroDMA @MicrochipMakes

Feather M0 Sine Wave generator using ZeroDMA

Work by Adafruit forum members MartinL2 and BDL has provided great work on generating variable frequency sine waves on the digital to analog converter (DAC) on Adafruit Feather M0 (Microchip SAMD21 based) microcontroller boards.

I’m trying to make a (dynamic) swept sine generator to test an analog filter response. I’d like to stop DMA, load in a new frequency table, and restart DMA using the new (updated) table. Initially I’ll use + and – from the console to control the frequency, but later I will make a linear sweep.


Following up on this thread. I have modified MartinL2’s code to perform either a chirp or or a swept sine wave with “constant power” per frequency. The former is easier to see on a scope, but does not have constant power per frequency. This is true because each frequency (single cycle of a sine wave) is shorter and shorter as the frequency increases. If one observes this on an FFT, one sees the power per bin decreases as the frequency increases. The constant power mode emits a frequency for a unit time before changing. In this way the power as observed by an FFT should be constant. This mode is useful for characterizing filter frequency responses.


See this Adafruit Forums post for the details and the source code as it was developed. Great work!

Also, check out the Adafruit ZeroDMA Library in the Arduino IDE for all you can do.

And, check out the large number of SAMD21 (M0) based boards available from Adafruit.

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.

Join 35,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

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 https://www.instagram.com/adafruit/

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

Maker Business — Moving manufacturing out of China

Wearables — Where should I cut on my Neopixel LED strip?

Electronics — Solder isn’t everything.

Python for Microcontrollers — Python on Microcontrollers Newsletter: ESP32 Web Workflow for CircuitPython, CircuitPython Day 2022 and more! #CircuitPython @micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Detect Radiation, ML Baby Monitor, 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! — #NewProducts 8/3/22 Feat. LCD FeatherWing from Oddly Specific Objects! #adafruit #diyelectronics #newproducts

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

No Comments

No comments yet.

Sorry, the comment form is closed at this time.