Reliable molecular switch

by Eric Bogers @

Nanotechnology repeatedly breaks new records in the area of miniaturization. However, there are physical limits when reducing the size of electronic components and these will be reached in the near future. This means that new materials and components will be required – and it is here where molecular electronics will play a role. Researchers from the Karlsruher Institut für Technologie (KIT) have succeeded in developing a molecular toggle switch, which will not only remain in the selected position, but can also be switched as often as desired without any deformation taking place.

Reliable molecular switch – [Link]

Simple Pressure Sensor Amplifier & Over Pressure Switch

The pressure sensor amplifier built using LM358 op-amp and MPXM2051GS pressure sensor from NXP semiconductor.  The circuit provides 4V output for full scale pressure input 0-7.5PSI.  One op-amp is used as amplifier and 2nd op-amp is used as comparator to provide an output at set value that can be used as over pressure switch to control a pump or solenoid.  This is a low cost general-purpose circuit for those applications where +/-3% performance is acceptable. Multi turn potentiometers are provided for Offset, span adjust & over/under Pressure set point to control output devices like solid state relay, Pump, and solenoid.


  • Supply 12V DC
  • Pressure Sensor range 0-7.5PSI
  • Output 0-4V (Approx.)
  • PR1 Multi-Turn Potentiometer Offset
  • PR2 Multi-Turn Potentiometer Span Set
  • PR3 Multi-Turn Potentiometer Comparator (Switch) output Set
  • D1 Power LED
  • CN1 4 Header Connector Outputs & Supply Input

Simple Pressure Sensor Amplifier & Over Pressure Switch – [Link]

50 Segment Serial Bar-Graph Display Driver

The serial controlled 50 Segment Bar-Graph Display built using CAT4016 IC. Very useful projects for development Bar-Graph based, Temperature Meter, Interactive Games, Voltage Display, Current Display., Pressure Sensor, Magnetic field meter and PH Meter. Tilt meter, LUX meter.

The CAT4016 is a 16 channel constant current driver for LED billboard and other general display applications. LED channel currents are programmed together via an external RSET resistor. Low output voltage operation on the LED channels as low as 0.4 V (for 2 to 100 mA LED current) allows for more power efficient designs. A high−speed 4−wire serial interface of up to 25 MHz clock frequency controls each individual channel using a shift register and latch configuration.

50 Segment Serial Bar-Graph Display Driver – [Link]

3.3V @ 1.5A Buck Regulator

The circuit presented here is based on LTC3601, a high efficiency, monolithic synchronous buck regulator from Linear Technology. The circuit operates at an input voltage ranging from 4V to 15V, this makes it suitable for a wide range of power supply applications. It is capable of producing a output voltage of 3.3V. Burst Mode operation and forced continuous mode are the two types of operational modes available in LTC3601.


  • Input(V): 4VDC to 15VDC
  • Output(V): 3.3VDC
  • Output load: 1.5A
  • PCB:35mm X 25mm

3.3V @ 1.5A Buck Regulator – [Link]

Creating a Smart Water Sensor with the ESP32 Thing

Alex the Giant @ has a tutorial on how to build smart and connected water sensor using ESP32. He writes:

For this project, you can use either the ESP8266 Thing, or the ESP32 Thing. One of the many improvements made on the ESP32 is the capacitive touch circuitry built in to ten of the IO pins (we can see the pins capable of capacitive touch in the datasheet below). It should be noted though, that Touch1 cannot be used as capacitive touch sensor because of the pull-up resistor connected to GPIO pin 0. With the capacitive touch, we’ll be able to sense water with just two pins; the first will be connected directly to a capacitive touch pin, and the second will be connected to ground.

Creating a Smart Water Sensor with the ESP32 Thing – [Link]

110 GHz spectrum analyzer fits in your pocket

The MS2760A is the latest release in the Ultra-portable family of USB driven instruments – it can perform spectrum measurements from 9kHz to 110GHz in the industries smallest and lightest form factor. by Clemens Valens @

There was a time, and not so long ago, that spectrum analyzers were large and heavy instruments that had to be wheeled around on a trolley or mounted in a van for field operations. And their upper frequency stopped at say 10 GHz for the really expensive ones. Oh, how things have changed! Today it is possible to carry a spectrum analyzer in your pocket, or stick it on a drone and fly it around. What’s more, it measures frequencies up to 110 GHz.

110 GHz spectrum analyzer fits in your pocket – [Link]

The First and Only Long-Term Stable Metal-Oxide Gas Sensor

At this year’s Sensor+Test 2017 in Nuremberg (May 30 – June 1), Sensirion AG, the expert in environmental and flow sensor solutions, introduces the SGP – the first and only long-term stable metal-oxide gas sensor.

The SGP gas sensor is based on Sensirion’s multi-pixel platform, which integrates four gas sensing elements into a very small 2.45 x 2.45 x 0.9 mm3 DFN package featuring a fully calibrated air quality output signal. The unprecedented combination of long-term stability and multi-pixel technology opens up new possibilities for environmental monitoring in smart home, appliances and Internet of Things applications. Thanks to its unique performance, the SGP allows for the first time the integration of metal-oxide gas sensors into mobile devices.

The First and Only Long-Term Stable Metal-Oxide Gas Sensor – [Link] – check the availability of Raspberry Pi

ThePiLocator is a website aims to help you check the availability of pi zero and pi zero w on various online stores. – check the availability of Raspberry Pi – [Link]

LT8315 – 560VIN Micropower No-Opto Isolated Flyback Converter

The LT8315 is a high voltage monolithic flyback regulator that simplifies the design of an isolated DC/DC converter. By sampling the reflected isolated output voltage across the third winding on the power transformer, the part requires no opto-isolator or LT1431 for regulation. The LT8315 operates over an 18V to 560V input voltage range, has a 0.30A/630V integrated power switch and delivers up to 15 watts of output power, ideal for electric vehicles and battery stacks, as well as off line, automotive, industrial and medical applications.

LT8315 – 560VIN Micropower No-Opto Isolated Flyback Converter – [Link]

Educational Biomed Shield for Arduino 101

Orlando Hoilett has built his new biomedical Arduino 101 shield: Biomed Shield, in order to allow students, educators, and hobbyists to learn about bio-medicine by monitoring heart rate, temperature, and other physiological metrics.

To build this shield he used the following components:

  • AD5933
  • MLX90614
  • Microchip Rail-to-Rail Input/Output Dual Op-Amp
  • MAX30101: a specialized integrated circuit that is able to perform reflectance photoplethysmography
  • Photocell
  • Thermistor
  • AD8227

Orlando measured heart beats using transmission photoplethysmography using MAZ30101, where a light shines through an extremity such as a finger and a detector measures the amount of light that passes through. When the heart pumps blood through the body,  a momentary increase in blood volume in the fingers happens. As a result, the amount of light that passes through the finger changes with this changing blood volume and is detected by the photodetector.

Bioimpedance Measurement

Bioimpedance is can be another class of bioelectrical measurements where we measure the impedance of the body instead of measuring the electrical signals produced by the body with the help of AD5934 impedance analyser chip. He is also measuring body temperature with the MLX90614 and measuring the amount of light using  a CdS Photocell.

Orlando built this shield for education purposes not as a medical device, and his work on this shield is still in progress. Follow his project on to know more details and updates. You can check source files at Github.