プログラム

timer/timer.ino

// ---------------------------------------------------------------
/*
	timer.ino

					Sep/02/2021
*/
// ---------------------------------------------------------------
#include  <M5Core2.h>

hw_timer_t *timer1 = NULL;  

// ---------------------------------------------------------------
void IRAM_ATTR onTimer_proc()
{
  	int iix = millis() / 100;
 
	Serial.println("*** onTimer_proc *** " + String(iix));
}
 
// ---------------------------------------------------------------
void setup()
{
	M5.begin();

	timer1 = timerBegin(0, 80, true); 

	timerAttachInterrupt(timer1, &onTimer_proc, true); 

	timerAlarmWrite(timer1, 5000000, true); 

	timerAlarmEnable(timer1); 

	Serial.println("*** setup *** aaa ***");
	delay(1000);
	Serial.println("*** setup *** bbb ***");
	delay(1000);
	Serial.println("*** setup *** ccc ***");
	delay(1000);
} 

// ---------------------------------------------------------------
void loop()
{ 
  	float ffx = millis()/ 1000.0;
	Serial.println("\t*** loop *** aaa *** " + String(ffx));
	delay(3000);
  	ffx = millis()/ 1000.0;
	Serial.println("\t*** loop *** bbb ***"  + String(ffx));
	delay(3000);
  	ffx = millis()/ 1000.0;
	Serial.println("\t*** loop *** ccc ***"  + String(ffx));
	delay(3000);
}
 
// ---------------------------------------------------------------

Arduino IDE

実行結果

$ cu -s 115200 -l /dev/ttyUSB0
Connected.
	*** loop *** aaa *** 4.66
*** onTimer_proc *** 66
	*** loop *** bbb ***7.66
	*** loop *** ccc ***10.66
*** onTimer_proc *** 116
	*** loop *** aaa *** 13.66
*** onTimer_proc *** 166
	*** loop *** bbb ***16.66
	*** loop *** ccc ***19.66
*** onTimer_proc *** 216
	*** loop *** aaa *** 22.66
	*** loop *** bbb ***25.66
*** onTimer_proc *** 266
	*** loop *** ccc ***28.66
*** onTimer_proc *** 316
	*** loop *** aaa *** 31.66
	*** loop *** bbb ***34.66