AVR Freaks

small note:

you must wait for system oscillator change to finish, somthing like this at the end of your clock function would do the job:

while (CLKCTRL.MCLKSTATUS & CLKCTRL_SOSC_bm) {}

Am not quite sure what you mean by 416 because I thought you are using now 5MHz and you said the power consumption is lower.

my point was...

During wakeup:

Dont use 416KHz as a clock, this makes the CPU slower and you will consumer more energy to run your HW peripherals and so on, for example; and maybe its not relevant here...to run ADC, you need to have atleast 4-5 MHz as the conversion and the whole process needs this, otherwise the peripheral may behave weird and you will have high power consumption and lower efficiency. so I would suppose the USART peripheral is also consuming higher power "I dont know how much?" at this "416 KHz".

During sleep mode:

and allow me to correct it up in my #4, the comment in the code is wrong but the function is enabling the power down mode

int8_t SLPCTRL_init()
{

	SLPCTRL.CTRLA = 1 << SLPCTRL_SEN_bp /* Sleep enable: enabled */
					| SLPCTRL_SMODE_PDOWN_gc; // PW down mode

	return 0;
}

the waking up from sleep, consumes also some power. you have to check this with the oscilloscope and how much time does it require, it would be nice if we can see your HW setup. thats why while loop is necessary to wait for changing clock sources:

while (CLKCTRL.MCLKSTATUS & CLKCTRL_SOSC_bm) {}

In every case, I see that 100uA is quite reasonable consumption as it also depends on you HW, PCB shielding...grounding and so on. for this I cant give you an answer as I havent seen your HW setup.

what is your configuration for unused pins ?

Setting them to Output has been the norm, however, in the datasheet of these new tinys its suggested to disable them with pull-up configured as Jim suggested, from what I've seen this is done like this:

void mcu_init(void)
{

	for (uint8_t i = 0; i < 8; i++) {
		*((uint8_t *)&PORTA + 0x10 + i) |= 1 << PORT_PULLUPEN_bp;
	}

	for (uint8_t i = 0; i < 8; i++) {
		*((uint8_t *)&PORTB + 0x10 + i) |= 1 << PORT_PULLUPEN_bp;
	}
} //this is for an ATtiny214, 14 pins

I would suppose the concept goes to Atmega3209, you just need to add the missing pins PORTC...if existed.

To say the truth, from my experience i didnt needed to enable the port pull-up, as I noticed it consumes a little bit more power...

why you are deleting the information, it might help someone in the future...

Re-order your ISR, take away the cli() and sei(). mostly important make the shared variables between ISR and main as volatile.

in your ISR, put first the:

RTC.PITINTFLAGS = RTC_PI_bm;

where are you defining the F_CPU ?

Wrong!. #define F_CPU doesnt set the clock the MCU,its just a way to tell the chip what frequency you are running, so if you are running your chip at 416KHz then you should set according to this...if you are running it at 5 MHz then it should be 5 MHz.

I had time to measure the current consumption.
My target device is mega3208 and below is the circuit.

The following code toggles loop and sleep approximately every 2 seconds with a PIT interrupt.

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include <avr/cpufunc.h>
#include <stdbool.h>

volatile bool flg;

////////////////////////////////////////////////////////////////
// FUSE
////////////////////////////////////////////////////////////////
FUSES = {
    .WDTCFG     = FUSE_WDTCFG_DEFAULT,
    .BODCFG     = FUSE_BODCFG_DEFAULT,
    .OSCCFG     = FUSE_OSCCFG_DEFAULT,
    .SYSCFG0    = FUSE_SYSCFG0_DEFAULT,
    .SYSCFG1    = FUSE_SYSCFG1_DEFAULT,
};


////////////////////////////////////////////////////////////////
// INTERRUPT
////////////////////////////////////////////////////////////////
ISR(RTC_PIT_vect){
    flg = !flg;
    RTC.PITINTFLAGS = RTC_PI_bm;
}

////////////////////////////////////////////////////////////////
// MAIN
////////////////////////////////////////////////////////////////
int main(void){
    // CLOCK
    _PROTECTED_WRITE(CLKCTRL.MCLKCTRLA,!CLKCTRL_CLKOUT_bm | CLKCTRL_CLKSEL_OSCULP32K_gc);
    _PROTECTED_WRITE(CLKCTRL.MCLKCTRLB, !CLKCTRL_PEN_bm);

    // PORT
    PORTA.PIN0CTRL = 
    PORTA.PIN1CTRL = 
    PORTA.PIN2CTRL = 
    PORTA.PIN4CTRL = 
    PORTA.PIN5CTRL = 
    PORTA.PIN6CTRL = 
    PORTA.PIN7CTRL = 
    PORTC.PIN0CTRL = 
    PORTC.PIN1CTRL = 
    PORTC.PIN2CTRL = 
    PORTC.PIN3CTRL = 
    PORTD.PIN0CTRL = 
    PORTD.PIN1CTRL = 
    PORTD.PIN2CTRL = 
    PORTD.PIN3CTRL = 
    PORTD.PIN4CTRL = 
    PORTD.PIN5CTRL = 
    PORTD.PIN6CTRL = 
    PORTD.PIN7CTRL = 
    PORTF.PIN0CTRL = 
    PORTF.PIN1CTRL = 
    PORTF.PIN2CTRL = 
    PORTF.PIN3CTRL = 
    PORTF.PIN4CTRL = 
    PORTF.PIN5CTRL = 
    PORTF.PIN6CTRL = PORT_ISC_INPUT_DISABLE_gc;

    // PIT
    RTC.CLKSEL = RTC_CLKSEL_INT1K_gc;
    RTC.PITINTCTRL = RTC_PI_bm;
    RTC.PITCTRLA = RTC_PERIOD_CYC2048_gc | RTC_PITEN_bm;
    
    // SLEEP MODE
    SLPCTRL.CTRLA = SLPCTRL_SMODE_PDOWN_gc;

    // LOOP
    sei();
    while(1){
        while (flg);
        cli();
        sleep_enable();
        sei();
        sleep_cpu();
        sleep_disable();
        _NOP();
    }
}

The following is the waveform.

About 3.2V was applied to PS, and after initializing, SW was turned off and the voltage across 47k(5%) was observed with an oscilloscope.

Here is the result:
Active loop: 488mV = 10.4uA (VCC = 2.712V)
Sleep: 130mV = 2.77uA (VCC = 3.07V)

The current values and calculation results extracted from the data sheet are as follows.
RTC = 1.2uA
OSCULP32K = 0.4
CPU_ACT = 9.0uA(32KHz 3V)
CPU_PDOWN = 0.1uA

Active loop: 1.2 + 0.4 + 9.0 = 10.6uA
Sleep: 1.2 + 0.4 + 0.1 = 1.7uA

The value at the time of sleep doesn't suit too much. Please forgive me because it is a sloppy measurement.

If you dont mind guys, I will link this to my thread about getting started with 0&1 series...

Well, I would start with analyzing your PCB circuit concept...look for your HW, start removing part by part parallel to testing it

Very happy you fixed your problem, one last thing, maybe in the next design its better if you take a look at your PCB.

- Decoupling caps, are a little bit far from the mcu.

- Traces for V+make it a little bit bigger.

- I think you are using two layers PCB, so it would be nice if you added a GND top layer by adding via over the PCB "stitches"....its done easily in KiCAD and altium...

- Try to bring all the signal traces closer to each other...

- although its not critical in your application, but it would be nice if you inform yourself a little bit about EMC/EMI, noise and so on.

- for caps, you can use 0603 / X7R instead of 0805 (your caps looks like 0805 for me...dont know)

good luck with your project!

Moe