Free Electronic Circuit Design
Introduction: Analog-to-Digital Conversion Oversampling Every analog-to-digital conversion is designed for specific resolution depending on the bit (binary digit) width of the conversion. For example, a 10 bit ADC with 5V reference would have 5V/1024 resolution or about 4.883 mV. The intrinsic error related to the resolution is the digital-quantization error of ±0.5 bit. In other words, it should produce only […]
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Introduction: PWM (Pulse-Width Modulation) for Digital Audio Conversion Pulse width modulation (PWM) technique has been widely used for converting digital audio stream into audio signal since it is very simple and easy to implement. Many low-cost micro controllers include dedicated PWM controllers as their standards, and many engineers use it for many purposes. In this article, we present the solution […]
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Intoduction: Protecting The Arduino Uploaded Program Codes If you want to sell the final product developed with Arduino, then you need to protect the firmware from cloning. Similarly, you need the protection as well when selling an embedded software by selling the programmed microcontroller chip. Fortunately, there is a lock bits fuse that that is programmable using the ICSP interface. […]
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Product Description HMC936D-AM8 is a controller chip for HM-936D digital soldering station controller board. The controller is implemented using ATMEGA8 microcontroller, programmed with lock protection to disable the chip for being read or modified. It runs on 8MHz internal factory calibrated RC clock, so there is no need to provide XTAL and its related capacitors. The operational menu, custom sensor […]
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Introduction: Hardware Serial Vs Software Serial Arduino hardware and software development platform provides both hardware serial and software serial communication libraries. Hardware serial communication uses the microcontroller’s internal serial interface hardware that manage the digital signaling on its pin, even computing the parity bit for data transmission or for checking the received data if required (configured), so the CPU can […]
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A. Introduction: The 936 Soldering Station Series in The Market With the popularity of specific brand’s soldering station labeled with 936-series, many manufacturers (mostly Chinese companies) make benefits by producing the counterfeit products with the generic names “936 series” soldering station. It is a good things that their parts are widely available on the online marketplace, as shown in the […]
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Introduction: Microcontroller Software Design for Complex Processes Designing a software for complex tasks or processes will be easier if we organize the whole tasks into smaller functional tasks, where the tasks communicate each-other through common variables. For a functional task, a concept of state machine has been established for defining and describing the process details, which could ease the implementation […]
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This flip-flop circuit uses one potentiometer and one capacitor as the frequency determining components. The assembled circuit is shown in the Figure 1, and the schematic diagram of the circuit is shown in the Figure 2. The circuit consists of one integrated circuit of inverter gates (4069 CMOS or 74C04), one electrolytic capacitor, two resistors, two LEDs, and one potentiometer. […]
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Making a linear voltage regulator using 78XX integrated circuit series is very easy, it needs only one or two additional components to make the integrated circuit chip works. The problem arises when we need a custom voltage specs for the output, since they come in discrete fixed voltage variation (specified by XX parameter printed in the body of the IC […]
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The previous music-controlled disco light controllers, the audio-controlled disco light controller circuit and hi-lo (treble-bass) disco light controller have some features and drawbacks. The first one features high voltage drive, enable the circuit to drive 220VAC lamps, and the drawback is that it has only one way (single channel control). In the other side, the second version has two-way (bass […]
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Low Power Requirement of Indication and The Solution Visual indication using light emitting diode becomes very common, because LED technology offer many benefits: low power consumption, durable, and cheap. Some indication must be able to draw strong attention, or at least it must be very clear to read whether its state is on of off. In some application, the requirement […]
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To get various characteristic of an auto wah/quack effect, we need a flexible control of the envelope detection characteristic. Some playing styles need slow attack but fast decay, but some others don’t. Employing the envelope detector circuit presented in our previous article [Ref 1], but with some modification to make it single supply operation. Here we present the improvement of […]
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