Hey everybody
I have an issue waking my ATTiny2313A up from POWER DOWN sleep.
My original code was for an ATTiny85 with a tinycore on the arduino compiler.
Now I am converting my code to be used within Atmel Studio 7 with a ATTiny2313A.
Here is my code:
#include <avr/io.h>
#define F_CPU 8000000UL // 8 MHz
#include <util/delay.h>
#include <avr/sleep.h>
#include <avr/wdt.h>
#include <avr/interrupt.h> //for ISR interrupt)
// ATtiny2313A outputs for PWM
const char RedPin = PB2;
const char GreenPin = PD5;
const char BluePin = PB3;
// Variables for PWM color
unsigned char Red = 0;
unsigned char Blue = 0;
unsigned char Green = 0;
// Other variables
unsigned char SleepTime = 8;
ISR(WDT_OVERFLOW_vect)
{
// = executed on wake-up
}
void setup_watchdog(unsigned char timerPrescaler)
{
if (timerPrescaler > 9 ) timerPrescaler = 9; //Limit incoming amount to legal settings
unsigned char bb = timerPrescaler & 7;
if (timerPrescaler > 7) bb |= (1<<5); //Set the special 5th bit if necessary
//This order of commands is important and cannot be combined
MCUSR &= ~(1<<WDRF); //Clear the watch dog reset
WDTCR |= (1<<WDCE) | (1<<WDE); //Set WD_change enable, set WD enable
WDTCR = bb; //Set new watchdog timeout value
WDTCR |= _BV(WDIE); //Set the interrupt enable, this will keep unit from resetting after each int
//Sets the watchdog timer to wake us up, but not reset
//0=16ms, 1=32ms, 2=64ms, 3=128ms, 4=250ms, 5=500ms
//6=1sec, 7=2sec, 8=4sec, 9=8sec
//From: http://interface.khm.de/index.php/lab/experiments/sleep_watchdog_battery/
}
int main(void)
{
DDRB |= (1 << RedPin); // PWM output on PB2 - 0C0A
DDRD |= (1 << GreenPin); // PWM output on PD5 - 0C0B
DDRB |= (1 << BluePin); // PWM output on PD5 - 0C1B
TCCR0A = (15 << COM0B0) | (3 << WGM00); // fast inverted PWM on 0C0 A&B
TCCR0B = (1 << CS00); // clock source = CLK, start PWM -> check libraries do not want another value
TCCR1A = (3 << COM1A0) | (1 << WGM10);
TCCR1B = (1 << CS10) | (1 << WGM12);
OCR0A=0xFF; //Red
OCR0B=0xFF; //Green
OCR1A=0xFF; //Blue
Red=0x00;
Green=0x55;
Blue=0xAA;
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
while (1)
{
if(Red==0xFF) Red=0x00;
else Red++;
if(Green==0xFF) Green=0x00;
else Green++;
if(Blue==0xFF) Blue=0x00;
else Blue++;
OCR0A=~(Red); //Red
OCR0B=~(Green); //Green
OCR1A=~(Blue); //Blue
_delay_ms(10);
if (Red == 0xFF)
{ //sleepy mode
DDRB &= ~(1 << RedPin); // PWM input on PB2 - 0C0A
DDRD &= ~(1 << GreenPin); // PWM input on PD5 - 0C0B
DDRB &= ~(1 << BluePin); // PWM input on PD5 - 0C1B
setup_watchdog(SleepTime); //Setup watchdog to go off after Xsec
sleep_mode(); //Go to sleep! Wake up Xsec later and continue
DDRB |= (1 << RedPin); // PWM output on PB2 - 0C0A
DDRD |= (1 << GreenPin); // PWM output on PD5 - 0C0B
DDRB |= (1 << BluePin); // PWM output on PD5 - 0C1B
}
}
}
The PWM works perfectly till the Red = 0xFF trigger is reached.
The LED's switch off and the AVR powers down. (I tested this with a current meter, it does enter the POWER DOWN mode)
But when I expect it to wake up, and continue with the code, nothing happens.
I have searched this forum and google, but nowhere I can find answers that work.
Some notes:
- First I was still using the WDT_vect (for all tinies except the 2313..) I switched this to WDT_OVERFLOW_vect -> Did not solve the issue
- WDTCR vs WDTCSR: The manual for the 2313A talks about WDTCSR. I still had WDTCR in my code as it was originally for and ATTiny85. But as it now happens, the iotn2313a.h file has it defined as WDTCR. So no adjustment should be needed. I checked the register and it is the correct bit. Except for the 2313 it is defined as 0x21 and for the 2313A as 0x021. But this does not matter as it is the same value I presume.
Thanks for the help in advance.
