Allow for higher resolution with micros()

[sebromero]

Makes micros() use a higher resolution timer while keep using a low power timer for millis().
Test sketch:

unsigned long start, end;

void runTest(){
  for(int i = 1; i <= 64; ++i){
    start = micros();
    delayMicroseconds(i);
    end = micros();
    Serial.print("Delay: " + String(i) + " measured: ");
    Serial.println(end - start); 
  }
  Serial.println("-----------------------");
}

void setup() {
  Serial.begin(115200);  
  while(!Serial);

  Serial.println(millis());
  runTest();
  Serial.println(millis());
}

void loop() {}

[sebromero]

@facchinm We could also make low power the default option of course.

[github-actions]

Memory usage change @ cebd497

Board	flash	%	RAM for global variables	%
arduino:mbed:envie_m4	🔺 +64 - +64	+0.01 - +0.01	🔺 +24 - +32	+0.01 - +0.01
arduino:mbed:envie_m7	🔺 +64 - +128	+0.01 - +0.02	🔺 +32 - +32	+0.01 - +0.01
arduino:mbed:nano33ble	🔺 +64 - +128	+0.01 - +0.01	🔺 +32 - +32	+0.01 - +0.01

Click for full report table

Board	libraries/Scheduler/examples/MultipleBlinks flash	%	libraries/Scheduler/examples/MultipleBlinks RAM for global variables	%	libraries/doom/examples/Doom flash	%	libraries/doom/examples/Doom RAM for global variables	%	libraries/KernelDebug/examples/KernelDebug flash	%	libraries/KernelDebug/examples/KernelDebug RAM for global variables	%	libraries/Portenta_SDCARD/examples/TestSDCARD flash	%	libraries/Portenta_SDCARD/examples/TestSDCARD RAM for global variables	%	libraries/Portenta_Video/examples/Envie_video_coreboot flash	%	libraries/Portenta_Video/examples/Envie_video_coreboot RAM for global variables	%	libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo flash	%	libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo RAM for global variables	%	libraries/Portenta_System/examples/PortentaH7_updateBootloader flash	%	libraries/Portenta_System/examples/PortentaH7_updateBootloader RAM for global variables	%	libraries/ThreadDebug/examples/ThreadDebug flash	%	libraries/ThreadDebug/examples/ThreadDebug RAM for global variables	%	libraries/USBHOST/examples/KeyboardController flash	%	libraries/USBHOST/examples/KeyboardController RAM for global variables	%	libraries/USBHOST/examples/Shell flash	%	libraries/USBHOST/examples/Shell RAM for global variables	%	libraries/WiFi/examples/PortentaWiFiFirmwareUpdater flash	%	libraries/WiFi/examples/PortentaWiFiFirmwareUpdater RAM for global variables	%	libraries/PDM/examples/PDMSerialPlotter flash	%	libraries/PDM/examples/PDMSerialPlotter RAM for global variables	%
arduino:mbed:envie_m4	64	0.01	24	0.01	64	0.01	32	0.01	64	0.01	24	0.01	64	0.01	24	0.01	64	0.01	32	0.01
arduino:mbed:envie_m7	128	0.02	32	0.01	128	0.02	32	0.01	64	0.01	32	0.01	64	0.01	32	0.01	64	0.01	32	0.01	128	0.02	32	0.01	128	0.02	32	0.01	64	0.01	32	0.01	64	0.01	32	0.01	128	0.02	32	0.01	128	0.02	32	0.01
arduino:mbed:nano33ble	64	0.01	32	0.01																									128	0.01	32	0.01													128	0.01	32	0.01

Click for full report CSV

Board,libraries/Scheduler/examples/MultipleBlinks<br>flash,%,libraries/Scheduler/examples/MultipleBlinks<br>RAM for global variables,%,libraries/doom/examples/Doom<br>flash,%,libraries/doom/examples/Doom<br>RAM for global variables,%,libraries/KernelDebug/examples/KernelDebug<br>flash,%,libraries/KernelDebug/examples/KernelDebug<br>RAM for global variables,%,libraries/Portenta_SDCARD/examples/TestSDCARD<br>flash,%,libraries/Portenta_SDCARD/examples/TestSDCARD<br>RAM for global variables,%,libraries/Portenta_Video/examples/Envie_video_coreboot<br>flash,%,libraries/Portenta_Video/examples/Envie_video_coreboot<br>RAM for global variables,%,libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo<br>flash,%,libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo<br>RAM for global variables,%,libraries/Portenta_System/examples/PortentaH7_updateBootloader<br>flash,%,libraries/Portenta_System/examples/PortentaH7_updateBootloader<br>RAM for global variables,%,libraries/ThreadDebug/examples/ThreadDebug<br>flash,%,libraries/ThreadDebug/examples/ThreadDebug<br>RAM for global variables,%,libraries/USBHOST/examples/KeyboardController<br>flash,%,libraries/USBHOST/examples/KeyboardController<br>RAM for global variables,%,libraries/USBHOST/examples/Shell<br>flash,%,libraries/USBHOST/examples/Shell<br>RAM for global variables,%,libraries/WiFi/examples/PortentaWiFiFirmwareUpdater<br>flash,%,libraries/WiFi/examples/PortentaWiFiFirmwareUpdater<br>RAM for global variables,%,libraries/PDM/examples/PDMSerialPlotter<br>flash,%,libraries/PDM/examples/PDMSerialPlotter<br>RAM for global variables,%
arduino:mbed:envie_m4,64,0.01,24,0.01,64,0.01,32,0.01,64,0.01,24,0.01,64,0.01,24,0.01,64,0.01,32,0.01
arduino:mbed:envie_m7,128,0.02,32,0.01,128,0.02,32,0.01,64,0.01,32,0.01,64,0.01,32,0.01,64,0.01,32,0.01,128,0.02,32,0.01,128,0.02,32,0.01,64,0.01,32,0.01,64,0.01,32,0.01,128,0.02,32,0.01,128,0.02,32,0.01
arduino:mbed:nano33ble,64,0.01,32,0.01,,,,,,,,,,,,,,,,,,,,,,,,,128,0.01,32,0.01,,,,,,,,,,,,,128,0.01,32,0.01

[facchinm]

What do you think about going high res for micros() and low power for millis() instead? It would turn into a much simpler patch with virtually no drawback ( micros() would stop counting during sleep but we can safely add an API to forcefully avoid sleeping when you need precise timing, wrapping sleep_manager_lock_deep_sleep() in something a bit more arduinish 🙂 )

[sebromero]

@facchinm Legit 😄 . I changed it. Is there a signification penalty in using two timers concurrently?
Am I right in the assumption that some devices may set DEVICE_LPTICKER=0 as they don't support a LP ticker? I added a fallback for that case.
I'd probably wait with adding a function to avoid sleeping until we have a use case. I currently can't think of one where you need micro seconds resolution during sleep.

[github-actions]

Memory usage change @ de988ef

Board	flash	%	RAM for global variables	%
arduino:mbed:envie_m4	🔺 +64 - +128	+0.01 - +0.01	🔺 +24 - +24	+0.01 - +0.01
arduino:mbed:envie_m7	🔺 +64 - +128	+0.01 - +0.02	🔺 +24 - +24	0.0 - 0.0
arduino:mbed:nano33ble	🔺 +64 - +128	+0.01 - +0.01	🔺 +24 - +24	+0.01 - +0.01

Click for full report table

Board	libraries/Scheduler/examples/MultipleBlinks flash	%	libraries/Scheduler/examples/MultipleBlinks RAM for global variables	%	libraries/doom/examples/Doom flash	%	libraries/doom/examples/Doom RAM for global variables	%	libraries/KernelDebug/examples/KernelDebug flash	%	libraries/KernelDebug/examples/KernelDebug RAM for global variables	%	libraries/Portenta_SDCARD/examples/TestSDCARD flash	%	libraries/Portenta_SDCARD/examples/TestSDCARD RAM for global variables	%	libraries/Portenta_Video/examples/Envie_video_coreboot flash	%	libraries/Portenta_Video/examples/Envie_video_coreboot RAM for global variables	%	libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo flash	%	libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo RAM for global variables	%	libraries/Portenta_System/examples/PortentaH7_updateBootloader flash	%	libraries/Portenta_System/examples/PortentaH7_updateBootloader RAM for global variables	%	libraries/ThreadDebug/examples/ThreadDebug flash	%	libraries/ThreadDebug/examples/ThreadDebug RAM for global variables	%	libraries/USBHOST/examples/KeyboardController flash	%	libraries/USBHOST/examples/KeyboardController RAM for global variables	%	libraries/USBHOST/examples/Shell flash	%	libraries/USBHOST/examples/Shell RAM for global variables	%	libraries/WiFi/examples/PortentaWiFiFirmwareUpdater flash	%	libraries/WiFi/examples/PortentaWiFiFirmwareUpdater RAM for global variables	%	libraries/PDM/examples/PDMSerialPlotter flash	%	libraries/PDM/examples/PDMSerialPlotter RAM for global variables	%
arduino:mbed:envie_m4	64	0.01	24	0.01	64	0.01	24	0.01	128	0.01	24	0.01	64	0.01	24	0.01	64	0.01	24	0.01
arduino:mbed:envie_m7	64	0.01	24	0.0	64	0.01	24	0.0	64	0.01	24	0.0	64	0.01	24	0.0	64	0.01	24	0.0	128	0.02	24	0.0	128	0.02	24	0.0	64	0.01	24	0.0	64	0.01	24	0.0	128	0.02	24	0.0	128	0.02	24	0.0
arduino:mbed:nano33ble	64	0.01	24	0.01																									128	0.01	24	0.01													128	0.01	24	0.01

Click for full report CSV

Board,libraries/Scheduler/examples/MultipleBlinks<br>flash,%,libraries/Scheduler/examples/MultipleBlinks<br>RAM for global variables,%,libraries/doom/examples/Doom<br>flash,%,libraries/doom/examples/Doom<br>RAM for global variables,%,libraries/KernelDebug/examples/KernelDebug<br>flash,%,libraries/KernelDebug/examples/KernelDebug<br>RAM for global variables,%,libraries/Portenta_SDCARD/examples/TestSDCARD<br>flash,%,libraries/Portenta_SDCARD/examples/TestSDCARD<br>RAM for global variables,%,libraries/Portenta_Video/examples/Envie_video_coreboot<br>flash,%,libraries/Portenta_Video/examples/Envie_video_coreboot<br>RAM for global variables,%,libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo<br>flash,%,libraries/Portenta_System/examples/PortentaH7_getBootloaderInfo<br>RAM for global variables,%,libraries/Portenta_System/examples/PortentaH7_updateBootloader<br>flash,%,libraries/Portenta_System/examples/PortentaH7_updateBootloader<br>RAM for global variables,%,libraries/ThreadDebug/examples/ThreadDebug<br>flash,%,libraries/ThreadDebug/examples/ThreadDebug<br>RAM for global variables,%,libraries/USBHOST/examples/KeyboardController<br>flash,%,libraries/USBHOST/examples/KeyboardController<br>RAM for global variables,%,libraries/USBHOST/examples/Shell<br>flash,%,libraries/USBHOST/examples/Shell<br>RAM for global variables,%,libraries/WiFi/examples/PortentaWiFiFirmwareUpdater<br>flash,%,libraries/WiFi/examples/PortentaWiFiFirmwareUpdater<br>RAM for global variables,%,libraries/PDM/examples/PDMSerialPlotter<br>flash,%,libraries/PDM/examples/PDMSerialPlotter<br>RAM for global variables,%
arduino:mbed:envie_m4,64,0.01,24,0.01,64,0.01,24,0.01,128,0.01,24,0.01,64,0.01,24,0.01,64,0.01,24,0.01
arduino:mbed:envie_m7,64,0.01,24,0.0,64,0.01,24,0.0,64,0.01,24,0.0,64,0.01,24,0.0,64,0.01,24,0.0,128,0.02,24,0.0,128,0.02,24,0.0,64,0.01,24,0.0,64,0.01,24,0.0,128,0.02,24,0.0,128,0.02,24,0.0
arduino:mbed:nano33ble,64,0.01,24,0.01,,,,,,,,,,,,,,,,,,,,,,,,,128,0.01,24,0.01,,,,,,,,,,,,,128,0.01,24,0.01