26 lines
820 B
C++
26 lines
820 B
C++
#include "hardware/pwm.h"
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#include "pico/stdlib.h"
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#include "sidetone.h"
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Sidetone::Sidetone(uint gpio) : m_gpio(gpio)
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{
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gpio_set_function(gpio, GPIO_FUNC_PWM);
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uint slice_num = pwm_gpio_to_slice_num(gpio);
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pwm_config config = pwm_get_default_config();
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pwm_init(slice_num, &config, true);
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}
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void Sidetone::on(uint freq)
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{
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// Calculate and cofigure new clock divider according to the frequency
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// This formula is assuming we are running at 125MHz.
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// TODO: Make this work for any frequency
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float clkdiv = (1.f / freq) * 2000.f;
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uint slice_num = pwm_gpio_to_slice_num(m_gpio);
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pwm_set_clkdiv(slice_num, clkdiv);
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// Configure duty to 50% ((2**16)-1)/2) to generate a square wave
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pwm_set_gpio_level(m_gpio, 32768U);
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}
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void Sidetone::off() { pwm_set_gpio_level(m_gpio, 0); } |