Power constraint is a critical consideration undertaken by designers when selecting a microcontroller for an application — particularly with IoT applications where power plays a vital role. IoT nodes are only useful in the field if they last for years or even a decade on a single battery. The race for lower power devices between…

Arduino force-sensitive resistor is a new family member of Arduino traditional resistive sensors. Resistive sensors respond to any physical quantity change by varying their resistance. A fixed voltage is applied across the sensor upon resistance change voltage drops. This voltage drop can be sampled, and physical quantity change can be measured. Generally, in a resistive…

A flex sensor is a variable resistor, which measures the amount of deflection or bending it undergoes. The bending or molding of the sensor is what affects its resistance and this is what differentiates it from a standard, variable resistor. A flex sensor’s resistance is directly proportional to the amount of bend that occurs. Its…

An oximeter is a device that measures the amount of oxygen carried by a person’s red blood cells. Oxygen provides energy for our bodies, supports the immune system, helps replace cells that degrade, and more. Low blood oxygen levels can indicate certain health issues. These levels can also decrease as we age, so it can…

This tutorial will teach how to use and program HMI (Human Machine Interface) display.HMI displays have been in the market for quite a long time, but their price dropped for the last two years, and now DIY makers are using them in projects. Note that HMI display is different from touch display. Touch display only…

A galvanic skin-response (GSR) sensor is used to measure the stress levels or emotional spikes in people it’s reading by using two special electrodes. When in a reactive or stressed state, the human body’s sweat glands are activated. This sudden elevation in sweat can be picked up and recorded by the electrodes of a GSR…

In this tutorial, we’ll learn how to interface the four-in-one BME680 pressure, gas, humidity, and temperature sensor with Raspberry Pi (RPi). This will include understanding how to log and retrieve data from a database. The BME680 can “communicate” with external controllers on either the serial peripheral interface (SPI) and I2C protocols. For this project, we’ll…

In this tutorial, we’ll learn how to measure distance and gesture by using the SparkFun ZX sensor and Arduino. Movement can be difficult to predict. However, advanced computer technology and artificial intelligence (AI) can detect gestures with ease. One of the least costly ways, however, is via an infrared (IR) sensor. The IR receiver on…

In this tutorial, we’ll learn how to measure the turbidity in water by using a sensor with Arduino. Turbidity refers to the relative clarity of a liquid. It’s a measure of the suspension of heavy particles, dust, and other matters (liquid/solid) that may leave water cloudy, unclear, or dense. For example, a heavy concentration of…

One of the most important elements of any aquarium is oxygen. Even though water is part oxygen, it’s bonded with hydrogen, which is tough to separate and breathe in — even for fish. In open streams and oceans, oxygen is dissolved in the water through the open air, rainfall, and the flow of the tide.…

In this tutorial, we will learn how to hack a TV (television) remote using Arduino. TV remote communicates with TV using infrared rays. Encoded commands and transmitted by remote, TV internal circuitry decodes them and performs an action on received commands. On the front of the remote, we have an IR led which emits IR…

Gesture recognition is a heavily studied and experimented topic around the globe. Tech companies are aggressively spending resources to get a breakthrough. Pushbutton and touch technology is in use for quite a long time. New and better technology is key to capture the market. This made the entire tech industry focus on new technologies. Among…

In this tutorial, you’ll learn how to build a do-it-yourself (DIY) metal detector using a proximity sensor with Arduino. Many similar projects use a coil and transistor, but it’s possible to use a proximity sensor instead of a coil. You’ll simply notice a difference in the range and power consumption. The range of proximity sensor…

In this tutorial, we’ll learn how to send a text message using an STM32 microcontroller and SIM900 GSM module. The SIM900 can communicate with an external controller by using the universal asynchronous receiver-transmitter (UART) interface. This means that any controller with a UART module can “talk” with the module. Fortunately, most STM32 microcontrollers have one…

In this tutorial, we’ll learn how to measure frequency by using microcontrollers. Unfortunately, microcontrollers are not equipped with frequency-measurement functions. So, for this project to be a success, we’ll need to interface multiple microcontroller peripherals before we can sufficiently measure the frequency of an external signal. Two of the most common methods for measuring the…

The idea of noninvasive current measurement is not new. Commercial devices are available which can measure current without any physical contact. However, the topic was not popular among the DIY community because of the complexity and nonexistence of the compact non-invasive sensors, which could be studied at low power. Luckily, we have small and reliable…

LiDAR, or “light detection and ranging,” is a remote-sensing method that uses light in laser form to measure distances or ranges. LiDAR has been used for decades although there are more recent advancements in the technology. These include laser scanning and processing speeds that make 3D mapping possible and accessible. This technique uses light (precise…

BME680 is a multi-purpose digital sensor, developed by Bosch after years of research, which can measure temperature, humidity, gas, and barometric pressure. Communication with this sensor is possible via the Serial Peripheral Interface (SPI) and I2C protocols. The temperature and barometric pressure accuracy are +-1 and the humidity is +-3. The gases are measured as…

This tutorial is about building a DIY audio player using Arduino. Today audio players can commonly be found across many electronic products. Almost every mobile has an audio player. Audio technology gets a drastic improvement with rapid development in silicon technology. Previously audio data was stored on tape devices and CDs. But now, Flash memories…

In this tutorial, we’ll learn how to detect fire or a flame using Arduino. Since fire generates heat, it’s possible to measure it via a sensor that tracks the temperature of the environment and converts it into data that can be monitored. However, a temperature sensor is not always a reliable solution for distinguishing fire…