Within the realm of electronics, Arduino's adaptability takes center stage, showcasing its prowess beyond convention. The Arduino sine wave generator emerges as a pivotal tool, reshaping traditional perceptions tied to different types of oscillators. This evolution highlights Arduino's innovation in generating sine waves, bridging the gap between conventional oscillators and its versatile capabilities. Sine wave signal are required in many applications, such as sound and audio projects, as carrier in RF circuits and other electronics circuits. For example in the Arduino AM transmitter tutorial, sine wave signal from Arduino was generated and used as RF carrier signal.
Through the use of Arduino's CTC (Clear Timer on Compare Match) mode, the platform adeptly generates square wave signals, laying the groundwork for sine wave synthesis. A strategic integration of low pass filtering methods transforms these square waves into pristine sine waveforms. This unique fusion not only redefines signal generation but also reimagines the scope of Arduino's functionalities.
The following shows circuit diagram of Arduino sine wave generator.
Here the Arduino is a code that generates square wave using the CTC mode. Here the frequency of the square wave is 1.95KHz. You can use the Arduino CTC mode calculator to calculate the count value required to set the counter. See the use of this calculator below.
The square wave output at pin 6 is amplitude limited using a 10kohm potentiometer. The amplitude limited square wave is then converted to sine wave using a sallen-key low pass filter and the component values were computed using the online sallen-key low pass filter calculator which is a unity gain filter. For example for the above circuit, the component values for sallen key 2nd order low pass filter is shown below using the calculator.
For filters with gain see 2nd Order Active LPF Calculator.
The Arduino code for generating square wave of frequency 1.95KHz using CTC mode is provided below.
void setup () {
//Pin 6 (OC0A) is output
pinMode(6, OUTPUT);
// reset timer 0 control registers
TCCR0B = 0;
TCCR0A = 0;
// Load 63 to generate 1.95 kHz sq.wave
OCR0A = 63;
// Toggle OC0A on compare match, WGM 2 (CTC)
TCCR0A = (1 << COM0A0) | (1 << WGM01);
// Start the timer, with 64 prescalar
TCCR0B = (1 << CS00) | (1 << CS01);
}
void loop() {
}
The sine wave so generated can be used in building Arduino AM Transmitter and other RF circuits with Arduino.
Moreover, Arduino's PWM (Pulse Width Modulation) mode emerges as more than a mere modulation tool—it intertwines with filtering mechanisms to refine signals. By leveraging filter calculators, PWM generated signals undergo tailored transformations, expanding Arduino's applications across diverse signal processing landscapes.
The collaborative interplay between Arduino's capabilities—its sine wave generation, PWM modulation, and utilization of filter calculators—heralds a new era in signal manipulation. This symbiotic relationship between Arduino, oscillators, and filters amplifies the platform's utility, underscoring its adaptability for enthusiasts and professionals alike.
The amalgamation of the Arduino sine wave generator, different types of oscillators, 2nd order low pass filter calculator, Arduino AM transmitter, Sallen-Key low pass filter calculator, and Arduino fast PWM portrays a narrative of innovation, propelling Arduino beyond its conventional boundaries into the realm of signal processing mastery.
