Using //https://101010.fun/iot/m5stickc-plus-firststep.html
for inspiration, we can upload this program:
#include <M5StickCPlus.h>
void setup() {
M5.begin();
M5.Lcd.setTextSize(3);
M5.Lcd.setRotation(3);
M5.Lcd.setTextColor(TFT_ORANGE);
}
void loop() {
M5.update();
soundTest();
}
void soundTest() {
for (int tone=100; tone < 4000; tone=tone+50) {
M5.Lcd.fillScreen(BLACK);
M5.Lcd.setCursor(80, 50);
M5.Lcd.printf("%d", tone);
M5.Beep.tone(tone);
M5.Beep.update();
delay(200);
}
}
According to my ears there is a definite peak about 2500 Hz, with frequencies under 250 Hz and over 3000 not audible. Your ears may vary .....