Author Archives: the machinegeek

Free Virtual Audio Cable alternative

RTL-SDR enthusiasts who use Windows are familiar with the need for a virtual audio device to connect the SDR output to decoder programs such as dsd. The hangup is that you need to purchase Virtual Audio Cable software to the tune of $25 (more than the cost of the SDR dongle itself.) Now there’s a […]

Analog Devices releases free version of RF design tool

Analog Devices, Inc. (ADI) released a new version of its popular ADIsimRF design tool: The free design tool is the software accompaniment to ADI’s complete portfolio of RF-to-digital functional blocks, allowing engineers to model RF signal chains using devices from across ADI’s RF IC and data converter portfolio. ADIsimRF Version 1.7 adds a number of […]

Notacon 10 – DIY Neuroscience, EMGs, EEGs, and other recordings

In this presentation from the recent Notacon 10 conference in Cleveland, OH, Karin Halsey (aka meecie) provides a thought provoking roundup of the tech basics behind medical sensors and related devices. The talk focuses on working with basic supplies and DIY kits to measure biometric information.

Mystery Arduino device makes US TV debut on The Following

Looks like Arduino has made it to the small screen! The Following is an American TV Series which premiered last January and telling the story of former FBI agent Ryan Hardy (Kevin Bacon) and his attempts to recapture serial killer Joe Carroll following the latter’s escape from prison. On the 9th of April Season 1, […]

Mobile POV device uses Parallax Propeller

Here’s a unique mobile POV device using the Parallax Propeller. Gareth (chiprobot) designed this gadget using the Propeller MCU driving eight UV LEDs, blasting UV light onto a phosphorescent sheet of vinyl. He says the coding utilizes the Propeller’s built-in ROM character map, so code size is very small (i.e., no big data tables). You […]

Cypress announces Arduino shield-compatible PSoC 4

Cypress Semiconductor has announced the availability of their new PSoC 4 system-on-chip device The chip features an ARM Cortex-M0 CPU up to 48MHz, up to 32 kB Flash, 4 kB SRAM, programmable analog: Op-Amps, 12-bit 1Msps SAR ADC, programmable digital: Four PLD-based Logic Blocks, CapSense touch sensing capability, low power operating range of 1.71 to […]

Tiano-MSP430 based touchscreen piano

Rohit Gupta writes in about Tiano, a Touchscreen Piano he designed using MSP430. He used a resistive touchscreen and a MSP430G2553 (although MSP430G2231 would also do). He obtained useful information in designing this project from app notes from Atmel on the touchscreen theory of operation and from TI on the touchscreen control coding.. Via the […]

Free PDF of “Hacking the Xbox” in honor of Aaron Swartz

Our friend Andrew “bunnie” Huang along with No Starch Press have decided to release a free ebook version of Hacking the Xbox in honor of Aaron Swartz. Bunnie writes, “As you read my book, I hope that you’ll be reminded of how important freedom is to the hacking community and that you’ll be inclined to […]

Notacon 10 – DC to Daylight: A whirlwind tour of the radio spectrum

Ever wonder what’s going on in those portions of the spectrum outside the regular broadcast and public safety bands? This video from the just concluded Notacon 10 conference in Cleveland, OH, provides a summary of the radio spectrum assignments from the proverbial “DC to daylight”. This presentation by Stormgren concentrates on those radio frequency assignments […]

Easy Pulse V 1.1 project update

Raj previously designed the Easy Pulse heart rate sensor. Now he informs us of an update: “I would like to inform you about the release of a new version of Easy Pulse sensor. The Easy Pulse sensor is designed for hobby and educational applications to illustrate the principle of photoplethysmography (PPG) as a non-invasive optical […]

RTL-SDR dsd tutorial: monitoring P25 digital voice

The crew over at RTL-SDR.com has posted a simple tutorial on using the RTL-SDR dongle and free SDR# and Digital Speech Decoder software (dsd) to monitor P25 digital radio voice comms. They describe, “Digital radio voice communications are becoming more commonly used in the radio spectrum. This is due to the various improvements offered over […]

Dead drop file sharing revisited

The concept of dead drops, where USB thumbdrives are installed in public places for the distribution of files “off the grid” has been a popular topic. Now Steve Schuler writes in with his new take on this concept currently featured in Science 2.0. His article describes low tech ways to place dead drop drives in […]

MIDI OUT for vintage Korg CX-3

Michael from AcidBourbon writes, “This project is about adding a MIDI output to a vintage organ, the Korg CX-3 (famous Hammond compact organ clone). My Korg was built in 1979, so before the introduction of the General Midi standard. But tapping into the right (only three) conducting paths on the main PCB and using a […]

TIDeals: eZ430-Chronos watch again

If you missed it before, TI is offering the Chronos Watch as their current week’s deal at $38 (plus shipping.) The eZ430 deal includes the wireless enabled watch, CC1111 USB RF access point, and a CD containing software and documentation. This is the watch featured in a recent post on hacking RF devices in the […]

Tutorial: receiving ACARS with RTL-SDR

This posting on RTL-SDR.com provides a good explanation of how to receive and decode the aeronautical digital communications known as Aircraft Communications Addressing and Reporting System (ACARS) generally found on 131.55 MHz. Their technique uses the RTL-SDR dongle tuned by SDR# which feeds into the decoding program. The tutorial also contains links to several videos […]

Simple DIY ECG + pulse oximeter (V2)

Scott Harden has designed an ECG/pulse oximeter combo project using LM324 op-amps. Scott describes, “This new project is fully documented and uses extremely common and cheap parts, all of which could be purchased at RadioShack. It serves as both an ECG *and* a pulse oximeter, depending on which leads are attached. It uses a single […]