Hello @ScheduleDisplay

please find an example here which (when turned on by power button) shuts down and wakes up from RTC about 7 hours later.

Note: only using the hour field gives you a maximum of 23 hours. If you need more you'll need to also use the day and maybe year fields.

Thanks
Felix

Hello @ghettokon

maybe related to the note at the bottom here?

Note: 2018.2A PCB version of the device does not support C2C (TypeC to TypeC) connection and PD power supply.

Thanks
Felix

Hello @PaulB

this should work automatically when you power from PoE exclusivly. The code (see here) checks if external power (e.g. on the M5 bus) is available and switches to use that. (But I think that only works if USB wasn't already plugged in.)

Note: kMBusMode* is no longer used.

Thanks
Felix

Hello @ScheduleDisplay

No, if the touch is enabled (first true) then that already is done there. See here.

Ok - battery - I am afraid I am not sure why it would fail then.

Thanks
Felix

Hello @ScheduleDisplay

no, I don't think there is a limitation. This is a regular alarm function of the RTC which should allow an alarm even years from now.

But I noticed that the code in the library adds a small delay(10) to make sure the I2C command to set the alarm time has finished before powering off.

The only other reason I could think of that the M5Paper doesn't wake up anymore would be a flat battery.

Thanks
Felix

Hello @ScheduleDisplay

my M5Paper starting with a flat battery returns the following numbers when the battery is charged (read every second):

3976, 3986, 3990, 3998, 4002, 4008, 4014, 4020, 4022, 4026, 4030, 4038, 4044, 4046, 4052, 4060, 4060, 4068, 4070, 4070, 4076, 4078, 4078, 4090, 4092, 4094, 4098, 4102, 4104, 4108, 4114, 4114, 4116, 4120, 4122, 4124, 4126, 4126, 4130, 4134, 4136, 4142, 4142, 4148, 4150, 4152, 4154, 4156, 4162, 4160, 4164, 4168, 4170, 4174, 4176, 4176, 4176, 4178, 4180, 4182, 4184, 4186, 4188, 4192, 4194, 4196, 4196, 4198, 4200, 4204, 4204, 4206, 4210, 4210, 4212, 4214, 4218, 4218, 4224, 4226, 4226, 4226, 4226, 4228, 4228, 4228, 4230, 4232, 4230, 4236, 4238, 4240, 4242, 4244, 4244, 4246, 4246, 4250, 4252, 4252, 4256, 4254, 4254, 4258, 4258, 4258, 4262, 4266, 4264, 4266, 4268, 4268, 4270, 4276, 4274, 4276, 4276, 4276, 4276, 4278,

I suspect that in your case, reading 4.35 V, the battery was almost full.

Thanks
Felix

Hello @PaulB

I can get it to work when I include M5Core2.h at the top, set the correct CS pin and initialize the M5Core2 LCD, Serial etc. at the top of setup(), e.g.

#include <M5Core2.h>
...
void setup() {
  Ethernet.init(GPIO_NUM_26);
  M5.begin();

//  // Open serial communications and wait for port to open:
//  Serial.begin(115200);
//  while (!Serial) {
//    ; // wait for serial port to connect. Needed for native USB port only
//  }

Thanks
Felix

Hello @ScheduleDisplay

it doesn't really matter as `M5.shutdown( wakeupDate, wakeupTime) essentially does the same. See here.

Thanks
Felix

Hello @ScheduleDisplay

M5.shutdown(secs) uses the timer function of the RTC. According to the documentation the timer is 8 bits and it slowest clock source is 1/60 Hz. So you get about 255 x 60 s = 15300 s which is roughly 4 h (= 14400 s).

Re 1.) So yes, there is a limitation of the sleep duration when using the timer function of the RTC.

If you need longer period than 4 hours you need to look into the alarm functionality of the RTC. E.g. you first need to read the RTC time, add the amount you want to sleep to it and then set the alarm accordingly.

M5.shutdown(const rtc_date_t &RTC_DateStruct, const rtc_time_t &RTC_TimeStruct) can be used to set the alarm, but it only works when you first calculate the alarm time in relation the actual time in the RTC.

Note: the actual time in the RTC resets when there is no USB and the battery has run out of juice. The actual time is not automatically the time on you wall clock (except when you actually set it in the RTC). But for the alarm function to be used it doesn't have to be synced with the wall clock - it's only important that you know the time the RTC so you can calculate the difference and set the alarm.

Re 2.) so no other shutdown function is needed.

Thanks
Felix

Hello @tomtom22

to you first question: it doesn't matter whether you press and hold the reset button to get the M5AtomS3 into download mode to burn firmware or let the automatic do it.

The press and hold the reset button method is available in case the automatic download mode fails. This can happen if for instance the currently running firmware has an issue causing the device to constantly reset.

I personally let the automatic download mode do its thing and only if that fails use the reset button method.

Thanks
Felix