Tag Archives: ARM

Tutorial: RFID tags with the NXP NFC controller PN7120 and Eclipse

via Dangerous Prototypes


Erich Styger writes:

Playing with RFID and NFC is definitely fun🙂, and they are everywhere! For a research project I’m exploring different RFID tags and solutions. I several types around for a long time, but never found the time to actually work on it, so last nightI thought I give it a try, and I have it working with GNU ARM and Eclipse, powered by the NXP FRDM-K64F board🙂

More details at MCU on Eclipse site.

Discover the latest Arduino build for ARM Linux

via Arduino Blog


As many of you already noticed, we recently released a new “Linux ARM” version of the Arduino IDE available for download on our website together with the usual “Linux 32bit” and “Linux 64bit.”

This release enables you to run the Arduino Software (IDE) on many of the mini PC boards based on ARM6+ processors currently on the market, including Raspberry Pi, C.H.I.P., BeagleBone, UDOO… just to name a few.


The Linux ARM release has been strongly supported by our community and we would like to thank all the people that helped to make this happen: GitHub handles @CRImier, @NicoHood, @PaulStoffregen, @ShorTie8, and to everyone that patiently tested and reported problems.

If you are interested (and brave!), you can read the full story and explore the complete list of collaborators below:


Disclaimer: The release is “experimental,” meaning that it mostly works but some boards do not work or may not produce the desired result… enjoy imperfection and give us feedback on Github!

nRF24L01+ 2.4 GHz wireless connectivity with the tinyK20 board

via Dangerous Prototypes


Erich Styger writes:

I’m using the tiny and inexpensive Nordic Semiconductor nRF24L01+ transceiver (see “Tutorial: Nordic Semiconductor nRF24L01+ with the Freescale FRDM-K64F Board“) in many projects: it costs less than $3 and allows me to communicate with a proprietary 2.4GHz protocol in a low power way (see “IoT: FreeRTOS Down to the Micro Amps“). I have that transceiver now running with the tinyK20 board too.

More details at MCU on Eclipse site.

Fobble, a general purpose wireless breakout board

via Dangerous Prototypes


Ken Boak  has been working on a general purpose wireless breakout board – Fobble:

As can be seen from the above picture it contains a number of key features:

  • A resident RFduino  Bluetooth Low Energy Module with ARM Cortex M0 processor
  • 2 layer pcb 50 x 50 mm format- with extended Arduino headers pin-out
  • An X-Bee footprint – with 0.1″ breakout headers – to add your own wireless module
  • Two push button switches – only 1 populated shown
  • Footprint for RGB 0505 LED
  • Detachable power and programmer section
  • Detachable side panels – to make 38 x 32 mm BLE Key Fob
  • 8 pin header to accept 1.3″ OLED display
  • 20mm coin cell or flat Li Po cell power – on rear of Fob pcb
  • Micro – USB connector for recharging Li Po
  • Side Prototyping areas – perforated in 0.1″ matrix
  • 7 pin and 5 pin headers to accept any RFduino accessory shields – for development work

Project info at Sustainable Suburbia blog.

Counting bits in hardware: Reverse engineering the silicon in the ARM1 processor

via Dangerous Prototypes


Ken Shirriff writes:

How can you count bits in hardware? In this article, I reverse-engineer the circuit used by the ARM1 processor to count the number of set bits in a 16-bit field, showing how individual transistors form multiplexers, which are combined into adders, and finally form the bit counter. The ARM1 is the ancestor of the processor in most cell phones, so you may have a descendent of this circuit in your pocket.

More details at Ken Shirriff’s blog.

Scratching Vinyl Straddles Physical and Digital Realms

via Hackaday » hardware

The life of a modern DJ is hard. [Gergely] loves his apps, but the MIDI controller that works with the app feels wrong when he’s scratching, and the best physical interfaces for scratching only work with their dedicated machines. [Gergely]’s blog documents his adventures in building an interface to drive his iPad apps from a physical turntable. But be warned, there’s a lot here and your best bet is to start at the beginning of the blog (scroll down) and work your way up. Or just let us guide you through it.

In one of his earliest posts he lays out his ideal solution: a black box that interprets time-code vinyl records and emulates the MIDI output of the sub-par MIDI controller. Sounds easy, right? [Gergely] gets the MIDI side working fairly early on, because it’s comparatively simple to sniff USB traffic and emulate it. So now he’s got control over the MIDI-driven app, and the hard part of interfacing with the real world began.

After experimenting a lot with timecode vinyl, [Gergely] gives up on that and looks for an easier alternative. He also considers using an optical mouse, but that turns out to be a dead-end as well. Finally, [Gergely] settled on using a Tascam TT-M1, which is basically an optical encoder that sits on top of the record, and that makes the microcontroller’s job a lot easier. You can see the result in the video below the break.

And then in a surprise ending worthy of M. Night (“I see dead people”) Shyamalan  he pulls timecode vinyl out of the grave, builds up a small hardware translator, and gets his original plan working. But we have the feeling that he’s not done yet: he also made a 3D printed optical-mouse holder.

We can’t wait to see more from [Gergely], and wouldn’t mind seeing some of the code behind this project either. In the mean time if all this leaves you feeling inspired to make your own DJ controls entirely from scratch, have a look at this completely DIY turntable project.

Filed under: ARM, hardware, musical hacks