klaute/SWRMeter
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

Added a function which allowes to set the PWM frequency

Browse source
This commit is contained in:
Kai Lauterbach 2024-02-12 11:37:25 +01:00
parent aa74f4e281
commit 69ac7c3f8a
2 changed files with 61 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
firmware/command_ctrl.ino
View file

@ -252,7 +252,7 @@ void cc_startMeasurement()
enableWaveformOutput();
pollWaveformGenerator(); // manually poll the waveformgenerator
si5351.output_enable(SI5351_CLK0, 0); // disable clock output 0
delay(1);
//delay(1);
} else {
disableWaveformOutput();
si5351.set_freq((uint64_t)freq * 100, SI5351_PLL_FIXED, SI5351_CLK0);

60
firmware/waveformgenerator.ino
View file

@ -42,6 +42,11 @@ void setWaveformFrequency(uint16_t frequency)
wf_freq = WAVEFORM_DEFAULT_FREQ_HZ;
}
wf_sample_us = 1000000UL / ((unsigned long)wf_freq * WAVEFORM_MAX_SAMPLES_NUM);
if (frequency >= 30 && frequency <= 1000000)
{
setupPWMFrequency(PWM_PIN, frequency);
}
}
void setWaveformDC(uint8_t dc)
@ -104,3 +109,58 @@ void pollWaveformGenerator()
}
}
}
void setupPWMFrequency(uint8_t pin, unsigned long frequency) {
byte prescalerbits = 0b001; // Voreinstellung: kein Prescaler (F_CPU)
unsigned long prescaler_value;
unsigned long ocr;
// Berechne den idealen Prescaler für die gewünschte Frequenz
prescaler_value = F_CPU / frequency;
// Finde den passenden Prescaler
if (prescaler_value < 65536UL) {
prescalerbits = 0b001; // Kein Prescaler (F_CPU)
}
else if ((prescaler_value >>= 3) < 65536UL) {
prescalerbits = 0b010; // Prescaler 8
}
else if ((prescaler_value >>= 3) < 65536UL) {
prescalerbits = 0b011; // Prescaler 64
}
else if ((prescaler_value >>= 2) < 65536UL) {
prescalerbits = 0b100; // Prescaler 256
}
else if ((prescaler_value >>= 2) < 65536UL) {
prescalerbits = 0b101; // Prescaler 1024
}
else {
prescalerbits = 0b101; // Prescaler 1024
frequency = F_CPU / (prescaler_value = 65535UL);
}
// Berechne den Wert für den Output Compare Register (OCR)
ocr = F_CPU / (prescaler_value * frequency) - 1;
// Timer konfigurieren
pinMode(pin, OUTPUT);
if (pin == 5 || pin == 6) {
TCCR0B &= ~0b111; // Prescaler löschen
TCCR0B |= prescalerbits; // Neuen Prescaler setzen
OCR0A = ocr; // Output Compare Register setzen
TCCR0A |= (1 << WGM01); // CTC-Modus aktivieren
}
else if (pin == 9 || pin == 10) {
TCCR1B &= ~0b111; // Prescaler löschen
TCCR1B |= prescalerbits; // Neuen Prescaler setzen
OCR1A = ocr; // Output Compare Register setzen
TCCR1A |= (1 << WGM11); // CTC-Modus aktivieren
}
else if (pin == 3 || pin == 11) {
TCCR2B &= ~0b111; // Prescaler löschen
TCCR2B |= prescalerbits; // Neuen Prescaler setzen
OCR2A = ocr; // Output Compare Register setzen
TCCR2A |= (1 << WGM21); // CTC-Modus aktivieren
}
}