CMOS-Based Galvanic Digital Isolator

Galvanic isolation is a principle of isolating electrical systems wherein it blocks the DC current flow (i.e. there is no direct conduction path). Isolation is the ability to couple one circuit to another without the use of direct wire connections. This technique is commonly used in two or more electric circuits that must communicate, but their grounds are at different potentials. It is an effective method to prevent unwanted current from flowing two units sharing a conductor. Its purpose is for safety by preventing accidental currents from reaching ground through a person’s body. This design features Silicon Labs' SI8642 CMOS digital isolator, which is a low cost, high performance, low power, and reliable isolated circuit. Read more

RGB LCD Display Electromyography using Arduino + MyoWare Muscle Sensor

Measuring muscle activity that uses electric potential as an indication to know the health, and diagnose muscles to its present status is referred to as electromyography (EMG). Electromyography also assesses the condition of nerve cell (also called as motor neurons) that controls the muscles and can detect neuromuscular disorders. The reference design is a LCD display electromyography using arduino plus myoware muscle sensor from Adafruit. The reference design features the standard LCD 181 also from Adafruit Industries LLC with the use of I2C/SPI character LCD backpack. The design also uses the muscle sensor surface EMG electrodes. Read more

Electronic LED Candle

This reference design is a simple electronic LED candle that is well suited for birthday occasion. It acts like a real candle, which constantly flickers and changes its light intensity depending on the airflow. It has 9 LEDs, which blinks at random period and phase that can also be blown by the user as if it is a real candle. It specially uses the C&K’s PTS830GM140 tactile switch, a micro-miniature switch with low profile and high actuation forces designed for wearable electronics. It features extremely low start-up voltage and high output voltage accuracy. Read more

ATmega328P-PU + VS1053 Based MP3 Player

The MPEG-1 or MPEG-2 Audio Layer III (MP3) is an audio coding format used to shrink the size of a large audio file into a smaller one (about 8.33% of the original file size), without affecting its sound quality. It is the most popular audio format downloaded and played on most digital audio players. Digital audio players basically use a digital signal processor (DSP) and a digital-to-analog converter (DAC) to play an MP3 file. The DSP processes the MP3 data and sends it to the DAC to convert it into an analog signal that can be heard if inserted into an audio amplifier with a loudspeaker. Read more

Ultrasonic Rangefinder Using Arduino Uno and PmodMAXSONAR

The rangefinder is a device that measures distance from the observer to a target being measured. The device uses a sensor as the method of gathering measurements of distance, such as ultrasonic, laser, and radar. The circuit is a DIY rangefinder using a PmodMAXSONAR ultrasonic sensor, an Arduino UNO, and a 16x2 LCD module. The ultrasonic sensor has an effective detection range of 6in - 255in. It can detect objects within 1in up to 20ft away. The PmodMAXSONAR can send range data in three methods: UART, analog and PWM. Read more

Industrial Firewire Cable with FireWire 400 Color Camera

The manufacturing industry has different automation setup. Some of the setup uses electronic devices for quality assurance and actual status monitoring like cameras, sensor module, and other related devices. The firewire cable used in this design has IP67 degree of protection with 5 meters in length. In this design, it illustrate an automation setup with a firewire 400 color camera and 1654028 industrial firewire cable of Phoenix contact integrated to a pc unit with protective circuit. Read more

PM2.5/PM10 Particle Sensor for Air Quality Monitoring

Air pollution is one major problem that every individual is at risk. The pollutant, that contributes to these increases as industrialization and technology upgrade. Particulate matter or “PM” is the term being given to such particles like smoke, dust, dirt, and soot, which can be found in the air. The particulate matters can be dangerous depending on concentration and sizes. The sizes which considered can cause health risk are PM10 and PM2.5, which among the said particulate matter, PM2.5 (approximately 1/30th the average width of a human hair) is the most harmful PM for the reason that it can penetrate and lodge deeply to the lungs. The PM2.5/PM10 particle sensor for air quality monitoring reference design is an analog-front-end design, which can measure the particle concentration and sizes in the air. The design uses INA132, a low power single supply differential amplifier consisting a precision op-amp with a precision resistor network. It comes also with OPA2320 and OPA320, which is a new family of low-voltage CMOS op-amp that features a linear input stage with zero-crossover distortions that delivers excellent common mode rejection ratio (CMRR) of typically 114dB over the full input range. Read more

6A H-bridge DC Motor Controller

Nowadays, most of the motor driver circuits make use of the H-bridge configuration for it enables the voltage to be applied across a load in either direction. Hence, it allows DC motors to run forwards and backwards. This design utilizes IFX9201SG 6A H-bridge motor driver manufactured by Infineon Technologies. The output of this integrated circuit can be pulse width modulated at frequencies up to 20kHz that enables operation above the human sonic range by means of PWM/DIR control. While the signal at the direction input defines the direction of the DC motor, the PWM signal controls the duty cycle. Read more

Soldering Smoke/Fume Extractor

The process of joining electronic devices to a PCB or soldering is always performed not only by electronic engineers or technicians, but also by hobbyists. In soldering, lead is used as filler metal to join the pins of an electronic device to the PCB pads. When lead is heated during soldering, it produces toxic fumes that are hazardous to humans when inhaled. Excessive exposure to lead oxide fumes can result in lead poisoning. As suggested by Occupational Safety and Health Administration (OSHA) agency, there should be proper ventilation during soldering to avoid or minimize exposure to lead oxide fumes. Read More

10W Stereo Class D Amplifier

This reference design is a simple 10W stereo amplifier providing a class AB performance with class D efficiency. Its efficiency is more optimized when a 12Ω to 16Ω speakers are loaded. It has an efficiency of up to 88% with a low quiescent current which is 24mA. In addition, this device is short circuit and thermal load protected and its power consumption has been reduced to increase battery life.  Read more