0

Hijacking power and bandwidth from the iPhone’s audio interface

Hijack-Ekg

Hijacking power and bandwidth from the mobile phone’s audio interface. Creating a cubic-inch peripheral sensor ecosystem for the mobile phone… Thanks Sam!

HiJack is a hardware/software platform for creating cubic-inch sensor peripherals for the mobile phone. HiJack devices harvest power and use bandwidth from the mobile phone’s headset interface. The HiJack platform enables a new class of small and cheap phone-centric sensor peripherals that support plug-and-play operation.

Power. The HiJack energy harvester can supply 7.4 mW to a load with 47% power conversion efficiency when driven by a 22 kHz tone from the output from a single audio channel on the iPhone 3GS headset port, all using electronic components that cost just $2.34 in 10K volumes. We are exploring other approaches for achieving higher conversion efficiencies.

Data. The HiJack communications layer offers two data transfer schemes. The first allows 300 baud data transfer using Bell 202 FSK signaling. The second offers 8.82 kbaud using a Manchester-encoded, direct-digital communication using hardware accelerators on the HiJack microcontroller and a software-defined, digital radio modulator/demodulator on the phone. The first scheme is described in the ISLPED’10 Design Contest entry (below). The second scheme is described in the DEV’10 paper below.

Sensing. We envision a range of sensorboards including ozone, carbon monoxide, DVM, blood pressure, blood glucose, and others. But today, we only have four daughterboards: (1) a simple demo board with temperature/humidity sensors, PIR motion sensor, and potentiometer used on the early HiJack prototypes; (2) a 3-lead EKG sensor; (3) a basic soil moisture sensor; (4) a breakout board for fast prototyping on the latest generation of HiJacks.


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 14,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython 2019!

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm 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/


Maker Business — Facebook struggling to break into hardware

Wearables — Lacy wires

Electronics — It sure is crowded in here.

Biohacking — Vitamin-C + Gelatin for Accelerated Recovery

Python for Microcontrollers — Happy Ada Lovelace Day, thank you Mitsuharu Aoyama and more! #Python #Adafruit #CircuitPython #PythonHardware @circuitpython @micropython @ThePSF @Adafruit

Adafruit IoT Monthly — The S in IoT is for Security, Amazon announces Sidewalk and more!

Microsoft MakeCode — Xenomorph candy bucket and spooky workshops with MakeCode!

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.