ATtiny10 Cricket

3/1/26 Had started this in February, One of my co-workers wanted a device that sounds like its a cricket that make noise to annoy. So I chose the ATtiny10 with a 5x5mm piezo (very tiny speaker). With some c code, it works great! I chose to have it go at sudo random times and lengths. With this set up and re-chargeable 2032 batteries, it will run for days.

This was the first proto type to test it and make sure it was loud enough and sounds like a cricket. It worked. Took a lot of tweaking in the c code though.

PCB I've got Oshpark printing for me. Designed with kicad 9.0.7

C code done on command line with avr-gcc written with vi (vim).

/*    ATtiny10 Cricket - 1 MHz Version    ---------------------------------    Clock: 1 MHz internal    PB0 -> Piezo
    ATtiny10 (SOT-23-6 package)    =================================           _________          | |    PB0 1 |• 6| VCC    GND 2 | 5| PB3 / RESET    PB1 3 | 4| PB2          |_________|
    Pin Functions    ---------------------------------    1 PB0 - OC0A / PWM output    2 GND    3 PB1 - OC0B / ADC1    4 PB2 - ADC2 / INT0    5 PB3 - RESET / ADC3    6 VCC
    Notes:    - Cricket speaker on PB0 (OC0A)    - 8 MHz internal oscillator    - Timer0 used in CTC toggle mode*/
#define F_CPU 1000000UL
#include <avr/io.h>#include <avr/interrupt.h>#include <avr/sleep.h>#include <avr/wdt.h>
#define OCR_VALUE 14 // ~4200 Hz tone (prescaler 8) //// Not cleared on RESETvolatile unsigned char count __attribute__((section(".noinit")));const uint16_t chirpTime[]={2000,500,1000,3000,1000,2000,1000};
volatile uint8_t chirp_on = 0;volatile uint8_t chirp_count = 0;volatile uint16_t ms_count = 0;volatile uint16_t runtime_ms = 0;
void timer_start(void);void timer_stop(void);void watchdog_setup(void);
ISR(TIM0_COMPA_vect){    static uint8_t sub_ms = 0;    static uint16_t phase_timer = 0;
    if (chirp_on)        PINB = (1 << PB0); // toggle pin
    sub_ms++; //speed 4-fast 8-slow    if (sub_ms >= 8) //8 // ~1 ms (8 × 119us)    {        sub_ms = 0;        ms_count++;        runtime_ms++;        phase_timer++;
        if (chirp_on)        { //messed with sound putting to 5            if (phase_timer >= 25) //25            {                chirp_on = 0;                phase_timer = 0;                chirp_count++;            }        }        else        { //made it a much shorter chirp at 2 instead of 4            if (chirp_count < 4) //4            {                if (phase_timer >= 25)                {                    chirp_on = 1;                    phase_timer = 0;                }            }            else            { //made it much faster at 200                if (phase_timer >= 500) //500                {                    chirp_count = 0;                    chirp_on = 1;                    phase_timer = 0;                }            }        }    }}
int main(void){    DDRB |= (1 << PB0);
    // Disable ADC for lower power    ADCSRA &= ~(1 << ADEN);
    sei();    timer_start();
    while (1)    {        if (runtime_ms >= chirpTime[count]) //2000=2sec, 5000=5sec chirping        {            timer_stop();            PORTB &= ~(1 << PB0);
            runtime_ms = 0;            chirp_count = 0;            chirp_on = 0; count++; if(count>6){ count=0; }            watchdog_setup();            set_sleep_mode(SLEEP_MODE_PWR_DOWN);
//total sleep time:(put to count 0-6)            for (uint8_t i = 0; i < count; i++) // 15 = ~120 sec            {                sleep_enable();                sleep_cpu();                sleep_disable();            }
     sei(); //added to see if it helped the second round timing.            timer_start();        }    }}
//Wakefrom sleepISR(WDT_vect){}
void timer_start(void){    TCCR0A = 0;    TCCR0B = (1 << WGM02) | (1 << CS01); // CTC, prescaler 8    OCR0A = OCR_VALUE;    TIMSK0 = (1 << OCIE0A);}
void timer_stop(void){    TCCR0B = 0;    TIMSK0 = 0;}
void watchdog_setup(void){    cli();
    // Clear watchdog reset flag (important on tiny10)    RSTFLR |= (1 << WDRF);
    // Timed sequence to change WDT    CCP = 0xD8;    WDTCSR = (1 << WDIE) | (1 << WDP3) | (1 << WDP0); // 8 sec interrupt only
    sei();}