Low power mode and Attiny85 about cosa HOT 6 CLOSED

Hi Fabien. I have to start with the obvious questions; Have you measured with another test program ie not Cosa. And second what are you measuring with. To measure below 1 mA requires good tools, wired, etc

Cheers Mikael

25 sep 2013 kl. 14:41 skrev duayfabi [email protected]:

Hi, Mikael,

I'm currently testing your watchdog API to enable low power consumption with an Attiny85 (with Arduino IDE).

I taked one of your exemple (VWI transmitter) and modified it to only have the Watchdog part running.

Here is the final code I have :

#include "Cosa/Pins.hh"
#include "Cosa/Watchdog.hh"
#include "Cosa/Power.hh"

void setup()
{
// Set up watchdog for power down sleep
Watchdog::begin(1024, SLEEP_MODE_PWR_DOWN);

// Disable hardware
Power::adc_disable();
Power::timer0_disable();
Power::timer1_disable();
#if defined(ARDUINO_TINY)
Power::usi_disable();
#else
Power::spi_disable();
Power::twi_disable();
Power::timer2_disable();
Power::usart0_disable();
#endif
}

void loop()
{
SLEEP(2);
}
I measured a constant current of 250 - 300 µA (3.3 V and my Attiny is cadenced at 8 Mhz). I know it is possible to get a lower current, so, what's wrong with this code?

For info : BOD is disabled with the fuses and the only component I have on my breadboard is the Attiny85 and a resistor on the reset PIN (my ISP programmer is disconnected) and I have tested with two different tiny85 chip.

Any hints for me?

Thank you.

Fabien D.

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from cosa.

Hi again. I see one thing that you can test. You must disable the ADC and possible the timers. Check the ATmega manual for more details.

Cheers Mikael

25 sep 2013 kl. 14:41 skrev duayfabi [email protected]:

Hi, Mikael,

I'm currently testing your watchdog API to enable low power consumption with an Attiny85 (with Arduino IDE).

I taked one of your exemple (VWI transmitter) and modified it to only have the Watchdog part running.

Here is the final code I have :

#include "Cosa/Pins.hh"
#include "Cosa/Watchdog.hh"
#include "Cosa/Power.hh"

void setup()
{
// Set up watchdog for power down sleep
Watchdog::begin(1024, SLEEP_MODE_PWR_DOWN);

// Disable hardware
Power::adc_disable();
Power::timer0_disable();
Power::timer1_disable();
#if defined(ARDUINO_TINY)
Power::usi_disable();
#else
Power::spi_disable();
Power::twi_disable();
Power::timer2_disable();
Power::usart0_disable();
#endif
}

void loop()
{
SLEEP(2);
}
I measured a constant current of 250 - 300 µA (3.3 V and my Attiny is cadenced at 8 Mhz). I know it is possible to get a lower current, so, what's wrong with this code?

For info : BOD is disabled with the fuses and the only component I have on my breadboard is the Attiny85 and a resistor on the reset PIN (my ISP programmer is disconnected) and I have tested with two different tiny85 chip.

Any hints for me?

Thank you.

Fabien D.

—
Reply to this email directly or view it on GitHub.

from cosa.

Hi Mikael,

Yes, I have tested with a code of my own and I measured (with good tools and with the same chip) < 10 µA.

I see one thing that you can test. You must disable the ADC and possible the timers

Doesn't the code below do these?

Power::adc_disable();
Power::timer0_disable();
Power::timer1_disable();

Fabien

from cosa.

Hi Fabien.

Ok. First questions cleared. The Power class only handles the power setting and not the enable or disable of the hardware module. It is often done by a control register. The Cosa init enables the ADC.

Mikael

26 sep 2013 kl. 08:12 skrev duayfabi [email protected]:

Hi Mikael,

Yes, I have tested with a code of my own and I measured (with good tools and with the same chip) < 10 µA.

I see one thing that you can test. You must disable the ADC and possible the timers

Doesn't the code below do these?

Power::adc_disable();
Power::timer0_disable();
Power::timer1_disable();
Fabien

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from cosa.

Ok, I'll check this a disable the ADC, timers, etc. by using the registers.

Thank you

Fabien

from cosa.

Improve the Power class to avoid this issue; 877ffb4

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