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11 May 2015


C.H.I.P. is a computer. It’s tiny and easy to use.

C.H.I.P. does computer things. Work in LibreOffice and save your documents to C.H.I.P.’s onboard storage. Surf the web and check your email over wifi. Play games with a bluetooth controller. With dozens of applications and tools preinstalled, C.H.I.P. is ready to do computer things the moment you power it on.

C.H.I.P. is a computer for students, teachers, grandparents, children, artists, makers, hackers, and inventors. Everyone really. C.H.I.P. is a great way to add a computer to your life and the perfect way to power your computer based projects.

CHIP – The World’s First Nine Dollar Computer – [Link]

7 May 2015



When we hear the word “Ultrasonic” we often refer it to bats and dolphins communication. Technically, “Ultrasonic” applies to sound that is anything above the frequencies of audible sound, and includes anything over 20kHz. Frequencies used for medical diagnostic ultrasound scans extend to 10 MHz and beyond. This dog repellent ultrasonic circuit will chase away angry dogs. It comprises of a 555 timer IC, a speaker/piezoelectric and a little ferrite transformer.

The main part of this circuit is a 555 timer IC. A 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator, and as a flip-flop element. Derivatives provide up to four timing circuits in one package. You can use the 555 effectively without understanding the function of each pin in detail. Frequently, the 555 is used in astable mode to generate a continuous series of pulses, but you can also use the 555 to make a one-shot or monostable circuit. The 555 can source or sink 200 mA of output current, and is capable of driving wide range of output devices.

To use this circuit adjust 4k7Ω Resistor at resonance frequency of the piezo transducer for maximum amplitude of the repeller ultrasonic sound. At 11 KHz to 22kHz this can reach a value of 10Vpp and the buzzer is a passive one (without generator).

Note: Ultrasonic frequency must be set with a dog nearby.


4k7Ω Resistor
10uF Capacitor
10nF Capacitor
1k2Ω Resistor
4k7Ω Potentiometer
NC Push Button

Dog Repellent Ultrasonic Circuit 2 – [Link]

30 Apr 2015



This circuit is built to repel mosquito using high frequency sound. The design is comprised of LM555 timer which provides the pulse generation and precision timing. It is also a stable controller capable of monostable or astable operation. The 74HCT4017BQ device is a Johnson decade counter with 10 decoded outputs. It provides the signal to be fed into the 555 timer which is connected to the output piezo speaker. The piezo speaker generates the sound. The Bipolar Junction Transistors(BJT) BC337 and BC327 acts as the amplifier of the output sound. It forms the push-pull amplifier that is more efficient than a single-ended Class A amplifier.

Electronic Mosquito Repeller – [Link]

8 Apr 2015


by Mach_5 @ instructables.com:

This tutorial brings you from start to finish in constructing your very own smartphone. You will start by 3D printing a case, then soldering printed circuit boards together, assembly, and finally installing a mobile OS onto your phone and using Python to make it yours. You can learn more about this project at hackaday.io/project/5083

Build Your Own Smartphone using Raspberry Pi – [Link]

10 Mar 2015


PiJuice is the ultimate module for all portable Raspberry Pi projects. Includes many fun maker projects and a solar power version too!

As one of the smallest systems around there’s so many amazing things you could do with the Raspberry Pi if it was self-powered and portable. With PiJuice we want to provide not only the best portable hardware/software solution, but also a set of inspiring and affordable guided projects for fun, learning, and breaking out the Pi into the real world.

For the past year we’ve toiled and sweated over the technical minutiae of PiJuice so you don’t have to.


  • Onboard 1400 mAh “off the shelf” Lipo battery (with support for larger Lipo Battery up to 5000 mAH+) to last up to 24 hrs + in constant use!
  • Full UPS (Uninterrupted Power Supply) solution.
  • Integrated RTC (Real Time Clock)
  • On board intelligent on/off switch
  • Low power deep-sleep state with wake on interrupt/calendar event
  • Programmable multi-colored RGB led
  • Full power management API available to Raspberry Pi OS with auto shutdown capability when running low on batteries
  • Raspberry Pi HAT compatible layout, with on board EEPROM for easy plug and play operation
  • Low profile design, to fit inside lots of existing Raspberry Pi cases!

PiJuice – A Portable Project Platform For Every Raspberry Pi – [Link]

20 Feb 2015


by Liam Kennedy @ kickstarter.com:

Raspberry Pi gadget lights up when International Space Station is nearby with Live HD video from the ISS now with Wearable LEDs

The original version of the ISS-Above was funded through a successful Kickstarter nearly 1 year ago. Since then more than 800 ISS-Above’s have been installed worldwide.

At the heart of the ISS-Above is the lovable and successful single board computer called a Raspberry Pi. Over 5 million of these little computers have been sold worldwide.

The ISS-Above functionality has been drastically improved since the first Kickstarter with some truly remarkable new features – including the display of live HD video views of the earth directly from cameras on the International Space Station.

ISS Above HD+ with Wearable Bluetooth Low Energy LEDs – [Link]

19 Feb 2015


by Francesco Truzzi @ b.truzzi.me:

I needed a small, fast and reliable multi-voltage level translator (mainly for connecting ESP8266 boards to the Arduino, got tired of resistor networks pretty quickly) so I built a breakout board for TI’s LSF0204(D).

Datasheet and info here.

The LSF0204 is a nice little chip. It can translate up to 4 signals to and from the following values:

1.0 V ↔ 1.8/2.5/3.3/5 V.
1.2 V ↔ 1.8/2.5/3.3/5 V.
1.8 V ↔ 2.5/3.3/5 V.
2.5 V ↔ 3.3/5 V.
3.3 V ↔ 5 V.


LSF0204 breakout board: a bidirectional, multi-voltage level converter – [Link]

13 Feb 2015

The Twin-T narrow-band notch filter has an RC network that look like twin T’s.  An effective attenuation at a given frequency can be obtained with the Twin-T design.  The Q factor for this passive filter design  is about .25; to get a larger Q factor, an active design is necessary.  The Twin-T design works by phase shifting the input 180 degrees out of phase in the legs of the circuit and adding them again at the output to cancel at the desired frequency.

Twin-T Notch Filter – [Link]

12 Feb 2015


by acidbourbon @ acidbourbon.wordpress.com:

Soon after I played around with some simple sequencers and multiplexers to generate more complex sound patterns. I thought it would be cool to have a device to gate oscillators or switch multiplexers with a random sequence. But the the output should change at a defined rate. Can we build a simple random pattern/number generator that works synchronized with an external clock signal? I believe so.

Clocked 8-bit random pattern generator for CMOS synth – [Link]

29 Jan 2015


Raj over embedded-lab.com has build a prototyping board that facilitates the building of simple circuits. It includes a regulated power supply for both 3.3V and 5V, four output LEDs, four input switches, a buzzer, a potentiometer and an onboard breadboard. Using this board you can fast prototype your next project.

Experimenter Prototyping Board for easy circuit build – [Link]





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