The SilentSwitcher, A Quiet Mains-free Power Supply

Audio projects become smaller over time with the rapid advancement of technology. A traditional power supply is still considered large compared to audio projects size constraints and it may not fit such delicate applications that need to deliver a good sound with zero noise.

Jan Didden, audio specialist who is known for his own publications Linear Audio, has came up with a new idea that can help in perfecting audio projects. The SilentSwitcher is a 55 x 31 mm special power supply module designed to supply clean power to high-end analog and digital audio circuits.


“One goal of this power supply that it doesn’t need to connect to the mains, you can use it with a USB charger or with a power bank… All problems with ground loops and mains born noise are not existing”- Jan Didden, the designer of The SilentSwitcher

The SilentSwitcher uses a combination of switching and linear regulators to generate a stable and noise-free supply voltage. The module can be powered from a 5V USB adapter, or from a 5V power bank for complete isolation. It delivers ±150 mA and a choice of 6V, 5V or 3.3V at 0.5 A to benefit most of your applications. The absolute maximum input voltage is 12VDC but in normal operation it is preferable to limit it to 10VDC.

Output specifications:

  • Outputs (analog): +15 and -15 VDC at 150mA* each;
  • Output (6/5/3.3V): selectable 6, 5 or 3.3 VDC at 0.5A*;
  • Output noise (6/5/3.3V): less than 1mV broadband
  • Output impedance (analog): less than 10mΩ (+15V) and 80mΩ (-15V) at 20kHz
  • Output impedance (6/5/3.3V): less than 3mV drop with 100mA current step.

15V output at 150mA are provided thanks to the very low noise linear regulators of Texas Instruments TPS7A47, TPS7A33 that suppress all the noise from the switching regulator by a factor of one thousand even at 1 Megahertz. Such chips have driven zero noise to switcher technology and have shown incredible quiet and low noise performance.

Jan Didden talking about his product

The well designed board will help in keeping all elements quiet and avoiding excess radiation. There are 2- and 3-pin headers on the PCB to connect the load, and a 2-pin header for an On/Off switch. The connection to the 5V source is through a B-type USB connector or a standard 2-pin screw-type connector block. You can mount the PCB on the back of your enclosure with a hole cut out for the USB-B – no further input wiring required.

The SilentSwitcher Connections
The SilentSwitcher Connections

This power supply will be a great companion for your project! No need to think about wiring or transformers, and you won’t face any issues like mains hum or mains earth loops.

The SilentSwitcher is live on a Kickstarter crowdfunding campaign and there are only few hours left to go! You can get your own SilentSwitcher for $59 and you will receive a fully assembled and tested board.

More details are provided at the campaign page and at Linear Audio website.

UsbSafe² – Programmable dongle for protecting USB devices from USB hosts and chargers


USB connections can transfer both information and power. UsbSafe² is a device for protecting USB-connected hardware from both excessive voltage, current and unauthorized data access. Unfortunately, the practice of “juice jacking” (accessing data from a device connected to a public charging station), has become all too common. UsbSafe² provides a unique combination of an anti-juice jacking mode with protection from faulty power sources. With UsbSafe² you’ll feel safer knowing that your valuable gadgets are protected and secured, wherever you go and whatever you plug into!

UsbSafe² – Programmable dongle for protecting USB devices from USB hosts and chargers – [Link]

iBreathe, A Breathalyzer Based on Hexiwear

Knowing the amount of alcohol you drunk is becoming easier using the iBreathe Breathalyzer project by Dave Clarke. You just have to blow in the alcohol sensor, then it pings the result to a smartphone app and to the cloud to document it as a table so you can see alcohol intake through time.

4b97aef17d4668b96ae71a9e031c8ba0_preview_featuredThis breathalyzer with a custom Beer mug casing will let you know where do you stand on the scale form “Sober as a judge” to “Hangover incoming”!
Below the (foamy) surface, it has substance too: along the 3D-printed casing, it features an Alcohol click sensor hacked to work with 3.3V, a customized Hexiwear interface, and a smartphone app.

Trailer Video, you can check the full demo here

iBreathe Breathalizer took place at Hackster.ioHexiwear: The Do-Anything Device!” contest in partnerships with NXP, AutoDesk, Mouser, MikroElektronika, and ARM mbed. Amazing prizes like Oculus Rift and JD humanoid robotic kit will be awarded to 6 winners.

Developed by MikroElektronika, Hexiwear platform combines the style and usability found in high-end consumer devices, with the functionality and expandability of sophisticated engineering development platforms, making Hexiwear the ideal form factor for the IoT edge node and wearable markets. It is completely open-source and developed in partnership with NXP.

This contest emphasizes the role of Hexiwear as the foundation for future IoT inventions. This powerful IoT development kit is a small and sleek, low-power device packed with sensors to quantify yourself and the world around you. Wirelessly enabled, it can connect both to devices nearby – or to cloud servers far away. With Hexiwear you can create your own smartwatch, remote sensor tag, or sophisticated home controller. Plus, it comes with preloaded apps to give you a fast start.


In order to build this project you will need:

For software development you need access to these platforms ( iOS compatible)

The Hexiwear Docking Station is an expansion board for Hexiwear, the wearable IoT development kit. It provides an interface for programming, debugging, and enhancing Hexiwear with additional functionalities by adding click boards.

Alcohol click carries an MQ-3 Semiconductor sensor for alcohol. The gas sensing layer on the sensor unit is made of Tin dioxide (SnO2), an inorganic compound which has lower conductivity in clean air. The conductivity increases as the levels of alcohol gas rise. Alcohol click has a high sensitivity to alcohol and it can be used to detect alcohol in concentrations from 0.04 to 4mg/l. To calibrate the sensor for the environment you’ll be using it in, Alcohol click has a small potentiometer that allows you to adjust the Load Resistance of the sensor circuit. Alcohol click communicates with the target board through AN (OUT) mikroBUS line. It’s designed to use a 5V power supply only. While Hexiwear’s analog input is 3.3V, this sensor was hacked by adding a voltage divider on the output pin of the Click Board.

Modified Alcohol Click Schematics with 3V3 output
Modified Alcohol Click Schematics with 3V3 output

A speaking version is an update to the original project. For more details and step-by-step tutorial go to the project page on to get a complete walkthrough, including descriptions, 3D models, and code snippets.

The deadline for the contest has passed and winners will be announced on 21 Oct 2016. More information about other contestants are available here.

A Multi-Use Mini Sensor Platform

While developing a smart hardware project, such as control and automation systems, you will almost need to use different types of sensors for collecting and gathering necessary data. LastSamurai had designed a platform that aims to simplify the use of digital and analogue sensors.

img003The platform was developed based on MySensors Hardware, hardware components that ease up building of the DIY sensors. It tries to solve some issues that other platforms still have like housing. The developer wants to make it smaller than 5x5cm with SMD parts so it can fit in a small case along with a sensor and a battery.

This multi-sensor platform can be powered by a CR2032 battery, external batteries, or an external power brick. Its PCB contains these components:

  • Atmega328P, a high-performance Atmel 8-bit AVR microcontroller combines 32KB ISP flash memory, 1024B EEPROM, 2KB SRAM, and operates between 1.8-5.5 volts.
  • NRF24L01+, an ultra low power RF transceiver IC for 2.4GHz band and 2 Mbps data rate.
  • ATSHA204A, a crypto full turnkey security device with 4.5Kb EEPROM protected hardware-based key storage.
  • AMS1117,  an adjustable and fixed voltage regulator to reach the desired voltage level.
  • SDA/SCL pins for I2C sensors like the HTU21D and Si7021.
  • D2/D3 pins of the atmega which are the digital pins that controller the interrupts 0 and 1.
  • A1 and A2 to be able to connect analog sensors like a plant/soil humidity sensor.
  • Serial connection pins for debugging.
  • 6 pin ISP connection for programming.
OH Mini-Multi-use Sensor Platform
OH Mini-Multi-use Sensor Platform

The platform can be programed using Arduino pro mini settings, and can run either on 3.3V or 1.8V and 8MHz.

It is an open source project, so everyone can contribute on enhancing it  and adding more features. Anyone interested can build it himself by having access to all hardware and software resources at the project page and github repository.

ATtiny85 Light Sensor – I2C slave device


Paweł Spychalski build a photoresistor based daylight meter sensor connected via I2C bus using ATtiny85:

I love AVR ATtinyx5 series microcontrollers. They are cheap, easy to use, they can be programmed just like Arduinos and comparing to their size they offer great features. For example, they can be used as remote analog to digital converters connected to master device using I2C bus.

ATtiny85 Light Sensor – I2C slave device – [Link]

Regulator offers independent outputs


Susan Nordyk @ writes:

Housed in a 15×9×2.42-mm over-molded BGA package, the LTM8049 µModule dual-output DC/DC converter from Linear Technology is configurable for a combination of SEPIC and/or inverting operation by simply grounding the appropriate output rail. All that is needed to complete the design are input and output capacitors and a few resistors—a total of 7 components compared to approximately 30 components for a comparable discrete design.

Regulator offers independent outputs – [Link]

Program AVR Using Arduino the easy way


rik @ show us how to program AVR microcontrollers using an Arduino board.

Advanced hobbyists like me (and you, of course 😉) love to play with microcontroller. And the most famous microcontrollers for beginners are AVR series from Atmel™.  Almost all beginners in microcontroller-world have their Arduino boards lying on work table. Because it is so much easy, so much fun, and so much famous. Here I explained How to Burn Programs In Your AVR Microcontroller Using An Arduino.

Program AVR Using Arduino the easy way – [Link]

LC709501F – Li-ion, intelligent charge controller for next-generation power banks


by Graham Prophet @

ON Semiconductor has introduced a highly integrated single chip power bank charge controller for the development of next generation Li-Ion powered products. The LC709501F provides broad power and voltage/current output range of 5V, 9V and 12V operation, with a maximum charge/discharge capability of up to 30W through FET selection.

LC709501F – Li-ion, intelligent charge controller for next-generation power banks – [Link]

433MHz wireless module configuration


Dziku discuss how to configure a cheap 433MHz wireless module for serial communication:

HC-12 are cheap 433MHz wireless serial port communication modules with a range up to 1800m in open space. Each costs about $5 when bought from China, and 2 of them can create wireless UART link that can be used, for example, to transfer telemetry data from UAV. Or drive IoT device. Or connect sensors. Or whatever else one can think of.

433MHz wireless module configuration – [Link]

$4 Coin-sized Linux Computer with WiFi

VoCore is a small Linux computer with Wifi that can work as a full functional router. It runs OpenWrt on top of Linux. It contains 32MB SDRAM, 8MB SPI Flash and uses RT5350 (360 MHz MIPS) as its heart. It provides many interfaces such as 10/100M Ethernet, USB, UART, I2C, I2S, PCM, JTAG and over 20 GPIOs but its size is less than one square inch (25mm x 25mm). VoCore was launched in 2014 in a crowdfunding campaign and eventually it was 1937% funded! The $20 module had a lot of fans but most of them, such as students, were not able to afford it.

Designers of VoCore came up with a great solution!vocore2-raw-3-768x512 VoCore2 Lite is the newest product of the Chinese startup for just $4! A Coin-sized Linux computer, smart router and it is fully open source. With such an affordable module, wireless life will become easier and it will push forward the development of new IoT applications.

It is now live in a new crowdfunding campaign and again it is exceeding expectations with 400% funds in the first 10 days!
Campaign video

It has 300Mbps WIFI, 5 x ETHERNET, USB 2.0 Host, 3 x UART, 1 x SD, 2 x High Speed SPI, 3 x I2C, and 40+ GPIOs. It can be programmed in C, Java, Python, Ruby, Javascript and etc. It has various of docks and thousands of software to enhance its functions and the wireless life.

VoCore2 Pinout Diagram
VoCore2 Pinout Diagram

“People may ask, is that price lower than the cost? The answer is it is not, but it is very very very close to the cost, and only for us with the experience of production VoCore2(we reuse  the VoCore2 tech, test jig, test app, to save cost etc…). Just hope students and other cost sensitive people will have a chance to play with the most advanced IoT board.” – Qin Wei, VoCore co-founder

Using VoCore2 as a router

Compared to Vocore2, Vocore2 Lite has a cheaper Mediatek MT7688N MIPS processor, less memory and storage, WiFi is limited to 150 Mbps and an external antenna is required. With only 74 mA power consumption, VoCore2 will be more efficient than ESP8266, that consume around 250 mA, and it will be easily implemented in various projects.

This is a comparison between the three editions of VoCore


The crowdfunding campaign still have 1 month to go and  you can pre-order VoCore2 ($12), VoCore2 Lite ($4), and other docks starting from $29.

More details, updates and resources can be reached at the official site , the documentation, and the blog.