Arduino Beetle - The world's smallest Controller

Even though it's the smallest Arduino board, the Arduino beetle still has all the features of the Arduino Leonardo. This board is an impressive complement to the Arduino technology's understated design. The Atmel Atmega32u4 microprocessor serves as its foundation. Modern technology developments have led to the development of electronic gadgets that are lighter, more portable, and capable of carrying out various tasks.

These tools are cheap and can be utilized by anyone without extensive training. Although every Arduino board also functions as a microcontroller, not every microcontroller is an Arduino board. The Arduino board has built-in features that can be used without other connected components.

Arduino Beetle Features and Specifications

The primary specifications and characteristics of the Arduino Beetle are listed below:

• The board is miniature, measuring only 20 by 22 millimeters
• Uploading and testing can be done directly using Micro USB.
• Users will appreciate the V-shaped, big, gold-plated input/output ports, which are easy to twist wires onto and may be immediately stitched onto clothing using conductive thread.
• Two honeycomb-shaped power interfaces with gold plating
• BLINK indication in a magical light blue color
• The system requires a 5V supply and operates at 16MHz.
• There are ten digital I/O pins, five analog ones, and four PWM ones.
• Currently, the Bootloader consumes 4 KB of the 32 KB of available Flash memory.
• Cycles of Writing/Erasing: 10,000 Flash/100,000 EEPROM
• 20 years at 85°C and 100 years at 25°C for data retention
• It features an ATmega32u4 microcontroller

Beetle: Minimize Your Arduino Projects

One recent development in Arduino-based simplicity is the DFRobot Beetle. Having the processing power of an Arduino Leonardo while still being around the size of a quarter, this little guy makes it easy to scale back your projects without sacrificing features.

Now that I've had some experience with the Beetle, I'll share the knowledge and expertise I used to connect it to a Bluetooth HC-06 module successfully.

Step 1: Introduction to the Arduino Beetle

DFRobot has the Beetle on sale for about $8; the more you buy, the cheaper it gets. Because of its micro USB port, the Beetle can be easily programmed and operates similarly to an Arduino Leonardo. I'll only talk about how to make it Bluetooth-enabled.

Step 2: Strength

Although the Beetle's specifications state that it needs 5V to work, it may also run on 3.7V. It is useful since most LiPo batteries are available in most hobby shops and run at 3.7V. For convenience, use Tenergy, but any 3.7V source will work. Make sure it doesn't go beyond 5V, or you risk damaging the surface elements.

Inconveniently, the Beetle lacks a dedicated battery port, so you'll need to supply external power via the micro USB port or soldering on the female connector yourself. However, we'll observe some power terminals in the following phase.

Step 3: Choosing a Power Distribution Point

Power can be supplied to the Beetle using two connectors. Each end features a positive and negative (hot and ground) power terminal. The Beetle can be seen starting up with the battery in the images above.

After a successful code upload to the Arduino Beetle, the LED stops blinking and remains solid blue until digital 13 is written to the high state. Replacing the hot and ground wires will cause your Beetle to overheat, perhaps melting parts.

Step 4: Bluetooth HC-06

The HC-06 remains one of my go-to Bluetooth modules due to its simplicity and reliability. This component sends information from the Beetle to a PC using TTL serial connection via a virtual COM port.

Connecting this module in parallel with the Beetle circuit means that both can share the same 3.7V LiPo battery. The fact that this module costs only $5 is another excellent feature. All of these modules come with a default pairing code of 1234.

Step 5: Enabling Bluetooth and Beetle

You may power the Bluetooth module by connecting the...

What are Operational Amplifiers? How Do They Work?

When it comes down to it, an operational amplifier is just a multi-terminal linear IC. Op-amps are voltage amplifiers with external feedback elements like capacitors and resistors connected between their input and output terminals. An electrical voltage amplifier with high gain typically has a single-ended output and a differential input. Op-amps are utilized in various products across different industries and fields of study, making them one of the most ubiquitous electronic components.

What is an Operational Amplifier? 

Most operational amplifiers contain three connections: 2 high-impedance inputs and 1 low-impedance output. A negative (-) symbol is used to indicate an input that is inverting, whereas a plus (+) sign is used to indicate an input that is not inverting. The operational amplifier is a device used in signal chains, power supplies, and control systems that amplifies a voltage difference between its inputs.

Operational Amplifier Classifications 

Operational amplifiers can be categorized in one of four categories:

• Voltage amplifiers use input voltage to create an output voltage.
• A current amplifier is an electronic circuit that takes in and outputs another current.
• Transconductance amplifiers take in a voltage and produce a current as a result.
• Transresistance amplifiers take an input current and transform it into an output voltage.

Since operational amplifiers are typically employed for voltage amplification, that's what we'll be discussing here.

Types of Operational Amplifier

Depending on the range of voltages that go into and out of the operational amplifier, there are three main types: Dual Supply, Rail-to-Rail, and Single Supply. See below for a breakdown of the input/output voltage ranges for the various op amp types.

Dual Supply Operational Amplifiers

Since operational amplifiers are designed to boost low-level signals, the VEE of a dual-supply op amp must be reduced to below -1.5V in order to accept a 0V input. Due to its frequent usage of a negative power source, the resulting operational amplifier is known as a dual supply operational amplifier since it requires both positive and negative supplies. The LM4558 is a dual supply operational amplifier. Learning about the LM4558 Pinout will help you to fully understand how to use it.

Rail-to-Rail Operational Amplifiers

Recently, there has been a shift toward reducing energy use, and as a result, more and more sets are being operated at reduced voltages. Op amps must also function at low voltages, however if VCC falls to almost 5V, an op amp with a single supply can only accept input 1.5V below VCC, which can be problematic. A Rail-to-Rail operational amplifier, on the other hand, can work normally even if the input voltage changes from VEE to VCC.

Single Supply Operational Amplifiers

While a negative voltage is required to input signals approaching 0V when employing a dual supply operational amplifier, a single supply op amp does not require this. Because it can function with an input signal as low as the ground level, it's also known as a ground sense operational amplifier.

Characteristics of Operational Amplifiers 

Op-amps have a wide range of several crucial properties and parameters. More information about these traits is provided below.

Open-loop gain

In an op-amp, the gain amount attained in the absence of feedback is denoted by its open-loop gain ("A"). It indicates that the feedback loop is active. Except for when used with voltage benchmarks, an open-loop gain typically needs to be extremely big (10,000+) to be helpful.

Comparators that measure voltage do so by contrasting the voltages at their terminals. Voltage comparators can force the output to the rails in any direction, regardless of how minuscule the voltage difference is. Closed-loop systems benefit from high...

ESP32 Basics and Working

Similar to Arduino, ESP32 is a development board. Therefore, it offers all the capabilities required to construct your projects. You should be aware of who designed this board to comprehend it fully. You also need to know its primary purposes, how the ESP32 is used, and its technical characteristics.

Even while the ESP32 is greater than the Arduino UNO and ESP8266, that doesn't imply it's the best choice for every project. To use this microchip, we need to understand what it is, how it operates, and what makes it stand out from the crowd.

What is ESP32?

Espressif Systems developed the ESP32 using several low-cost, power-efficient modules and SoC.

The ESP32 is a successor to the ESP8266, a device that "surprised" Western experimenters in 2014. The first version of the ESP8266 was released on a module named the ESP-01, whose capabilities were mostly undocumented due to a lack of English paperwork. Immediately after the ESP8266's documentation was localized into English, a slew of curious tinkerers learned about the device's capabilities and swiftly gained widespread popularity.

The ESP32 design was enhanced in several areas over the ESP32 design. ESP8266 has WiFi. However, it provides BLE and Bluetooth. It comes with a dual-core design and is speedier. Additionally, it has an ultra-low power mode that is perfect for battery-powered tasks.

The compact ESP32 package offers numerous high-level interfaces, including:

• Switches for antennas
• Balun to regulate RF
• Power booster
• Amplifier with minimal noise
• Modulated energy and air filtration systems

It uses extremely little energy because it has power-saving features like a synchronized clock and different operation modes. Because of its low quiescent current consumption, the ESP32 chip is perfect for use in battery-operated projects and Internet of Things uses.

ESP32 Peripheral Features/Workings

The accompanying Block diagram showcases the ESP32's impressive peripherals.

ESP32 Pinout Diagram:

Digital pins

There are 34 digital pins all on the ESP32. These pins function similarly to the digital pins on an Arduino. Therefore, it allows us to connect external components such as screens, buttons, sensors, buzzers, and more to our creations.

Most of these pins support internal pull-up, high impedance, and pull-down states. They are, therefore, perfect for integrating matrix keyboards and buttons and implementing popular Charlieplexing LED control methods.

ESP32 WROOM module includes 25 GPIO pins, all inputs with or without a pull-up.

The "Recommended Operating Conditions" part of the ESP32 datasheet says that 40mA is the most current that can be drawn from a single GPIO.

Input only pins: 

• GPIO 34
• GPIO 35
• GPIO 36
• GPIO 39

Pins with pull-up INPUT_PULLUP

• GPIO14
• GPIO16
• GPIO17
• GPIO18
• GPIO19
• GPIO21
• GPIO22
• GPIO23

Pins without internal pull up

• GPIO13
• GPIO25
• GPIO26
• GPIO27
• GPIO32
• GPIO33

ADC (Analog to digital converters)

Analog sensors can be read from and written to using the same pins on the pinout diagram corresponding to the analog inputs on an Arduino board.

The ESP32's 18-channel A/D converter and 12-bit resolution (0-4096) make it possible to collect data from various voltage and analog-based sensors.

With several analog sensors, you may still create very small linked applications thanks to this.

Analog input pins:

• ADC1_CH0 (GPIO 36)
• ADC1_CH1 (GPIO 37)
• ADC1_CH2 (GPIO 38)
• ADC1_CH3 (GPIO 39)
• ADC1_CH4 (GPIO 32)
• ADC1_CH5 (GPIO 33)
• ADC1_CH6 (GPIO 34)
• ADC1_CH7 (GPIO 35)
• ADC2_CH0 (GPIO 4)
• ADC2_CH1 (GPIO 0)
• ADC2_CH2 (GPIO 2)
• ADC2_CH3 (GPIO 15)
• ADC2_CH4 (GPIO 13)
• ADC2_CH5 (GPIO 12)
• ADC2_CH6 (GPIO 14)
• ADC2_CH7 (GPIO 27)
• ADC2_CH8 (GPIO 25)
• ADC2_CH9 (GPIO 26)

DAC (Digital to Analog Converters)

The majority of Arduino boards produce analog voltages via PWM signals. Two 8-bit D/A converters are present...