ATtiny13A and 433MHz Transmitter


I have a probelm with my attiny13A and a 433mhz transmitter.
It should always sleep and only wake up if a button is pressed, external interupt, send data over 433mhz and go to sleep again.
I connected a LED to check if it wakes up, it does, but it doesn’t send the 433mhz Code.
The 433mhz Code works if i only upload it to the attiny.

Something is causing a problem and I can’t figure out what it is for the last few days.

Does someone has an idea whats wrong with my Code?

Here is my sketch:

#include <avr/power.h>
#include <avr/sleep.h>
#include <avr/interrupt.h>

#define PIN_TX (1<<PB3) // PB3 pin, goes to transmitter data pin

const int buttonPin = 0;
const int ledPin = 1;

void setup() {

  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);

  digitalWrite(ledPin, LOW);

  DDRB |= PIN_TX; // Set output direction on PIN_TX

void sleep() {

  GIMSK |= _BV(PCIE);                     // Enable Pin Change Interrupts
  PCMSK |= _BV(PCINT0);                   // Use PB0 as interrupt pin
  ADCSRA &= ~_BV(ADEN);                   // ADC off ADCSRA &= ~(1<<ADEN);
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);    // replaces above statement

  sleep_enable();                         // Sets the Sleep Enable bit in the MCUCR Register (SE BIT)
  sei();                                  // Enable interrupts
  sleep_cpu();                            // sleep

  cli();                                  // Disable interrupts
  PCMSK &= ~_BV(PCINT0);                  // Turn off PB3 as interrupt pin
  sleep_disable();                        // Clear SE bit
  ADCSRA |= _BV(ADEN);                    // ADC on ADCSRA |= (1 << ADSC);
  while (ADCSRA & (1 << ADSC));           // wait for completion

  //sei();                                  // Enable interrupts

ISR(PCINT0_vect) {
  // This is called when the interrupt occurs, but I don't need to do anything in it

void loop() {

  sleep();                      // sleep function called here

  for (int i = 0; i < 3; i++) {

  digitalWrite(ledPin, HIGH);
  digitalWrite(ledPin, LOW);

The 433mhz code is in a second tab in the IDE:
I got it from here: ATtiny13-transmitter-433Mghz/transmitter.ino at master · rustam-iskenderov/ATtiny13-transmitter-433Mghz · GitHub

#include <util/delay.h>

const short  nPulseLength = 350;

const short  nHighPulses_0 = (nPulseLength * 1);
const short nLowPulses_0 = (nPulseLength * 3);

const short nHighPulses_1 = (nPulseLength * 3);
const short nLowPulses_1 = (nPulseLength * 1);

const short nLowPulses_sync =  (nPulseLength * 31);

void send(char* sCodeWord){

  while (*sCodeWord != '\0') {
    PORTB |= PIN_TX; // same as digitalWrite high

    if(*sCodeWord == '0')
      PORTB &= ~PIN_TX; // same as digitalWrite low
    else    {
      PORTB &= ~PIN_TX;




If I upload the Code from the link (from github) to the attiny13a it works like it should, the 433mhz Code gets sent.

I cant tell you what is wrong with your code but the sleep function you are using looks a lot more complicated then it needs to be, this is what i am using on a similar project:

#include <avr/interrupt.h>
#include <avr/sleep.h>
const int buttonPin = 0;

ISR(PCINT0_vect) {

#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

int main(void) {

    pinMode(buttonPin, INPUT_PULLUP);
    ADCSRA &= ~(1 << ADEN); //adc off
    sbi(GIMSK, PCIE); // Turn on Pin Change interrupt
    sbi(PCMSK, PCINT0); // Which pins are affected by the interrupt

    sei(); // Enable global interrupts


  while (1) {
    if (!digitalRead(buttonPin)) //just to avoid sending on press and release(sends only on release)
      //send stuff here



Another thought, not code related INPUT_PULLUP can waste a lot of power over time mayby try a external pullup mayby 1M or at least 500k. and if the 433 transmitter are the same cheap ones I’m using, try driving the transmitter vcc from a pin on the attiny instead this also saves alot of power, just a thought
Best of luck man.

Thank you very much for your sleep code and the tips to reduce the power consumption.
It took me a bit longer to get it working, but it does work now.
I can`t even meassure the power consumption with my multimeter. It is below 0.1microA when sleeping.
To send the Code I need to send it around 35 times to receive it 4 times.

I connected the Button and external Pullup like in this picture:

Hello I'm happy its working for you, a few thoughts:
On the picture you have a pull down not a pull up(the resistor are from gnd not vcc) it will still work but if that is how you have it connected i would change

if (!digitalRead(buttonPin)) 
if (digitalRead(buttonPin)) 
to make sure it send on release and not on press, if you send on press then release interupt can mess with the transmission.

Another thing you should should have a lot more stable transmit, i tested the code and i miss only 1 message in 20, (7m distance)
Make sure the antenna lengths are correct and that you have all the caps you need(0.1uf and 10uf minimum)
Best of luck