Polyphonic MIDI Synth on an ATtiny2313: This is the fourth synthesizer cable I've built, the first three being based on the ATtiny85. I have been looking into ARM chips but haven't gotten to grips with them just yet. Instead, I decided go back to the ATtiny2313, which has a quarter...

NopHead wrote a review of Elektor 500ppm LCR meter: I recently bought a 500ppm LCR meter from Elektor because I didn’t have anything for measuring inductors or the ESR (equivalent series resistance) of capacitors, both of which are important for modern electronics, particularly...

Researchers at UC Berkeley (California) have developed an Android app that can detect vibrations from earthquakes using the standard sensors integrated into smartphones. Android app turns smartphones into a seismic network -...

Here is a simple way to measure an unknown inductance by forming a resonance LC circuit and measure it using an oscilloscope. Glen Chenier writes: One of our technicians recently asked for help determining the value of an SMT inductor. It was unmarked, and was many turns of very fine...

Researchers have developed a smartphone device that measures the cortisol concentration in saliva in order to define your stress levels. The new test is done in under 10 minutes and there is no need to send a salvina sample on a lab. The cost for each measurement is less than 5$...

LG Innotek has released an ultra-thin optical biometric sensor module designed to be used in wearables and smartphones to measure health parameters such as heartbeat, stress indicators and blood oxygen saturation level. The new sensor is more accurate than it's predecessors...

SolarBoost is an open source smart interface that allows you to build your own powerful and portable solar charger for your phone and other mobile devices. It has two USB ports and can provide 5V @ 2A at each of them and is controlled by a 8-bit 32MHz Microchip PIC microcontroller. It...

Here is a quick tear down of an IKEA 400 lm "Ryet" bulb. Cheapest bulb with full safety listing that I have ever seen. Selling for less than $2.00! Ryet IKEA LED Bulb teardown -...