ATTiny85 Serial communication with Bluetooth Module

Question

For a simple project I would like to use a ATTiny85 connected to a HC-06 Bluetooth Module so it can talk to my Android phone.
I wrote a code for my Arduino Uno and worked as expected. When I changed the code to use on my ATTiny85 I got an error saying that 'Serial' was not declared in this scope and assumed that the ATTiny does not support Hardware Serial.
I need to read a String when received and sleep the MCU when not receiving. I went to use SoftwareSerial and was not able to get a String, just the first char.
I approached it in some was, like defining a char string[10]; as global and string[i] = mySerial.read(); i++; inside the loop, but it keeps not working. Whether it is the sleep, or my work to read data, I couldn't make it work.

Can someone provide a way to put a ATTiny85 to sleep, wake up to receive a String through Serial and sleep til the next data through Serial, please?

To sleep I'm using

void sleep() {
 GIMSK |= _BV(PCIE); // Enable Pin Change Interrupts
 PCMSK |= _BV(PCINT3); // Use PB3 as interrupt pin
 set_sleep_mode(SLEEP_MODE_PWR_DOWN);
 sleep_enable(); // Sets the Sleep Enable bit in the MCUCR Register (SE BIT)
 sei(); // Enable interrupts
 sleep_cpu(); // sleep
 // woke up
 cli(); // Disable interrupts
 PCMSK &= ~_BV(PCINT3); // Turn off PB3 as interrupt pin
 sleep_disable(); // Clear Sleep Enable bit
 sei(); // Enable interrupts
}
ISR(PCINT3_vect) {
}

And my loop is something like

char inputString[10];
int i = 0;
void loop() {
 sleep();
 if (serial.available() > 0) {
 char inputChar = serial.read();
 if (inputChar == '2') { //Char to break
 //Do something and reset i
 } else {
 inputString[i] = inputChar;
 }
 i++;
 }
}

Thanks to all.

• RubberDuck: You could easily overflow your buffer here. It’s a fixed 10 bytes, but nothing checks to see if you’ve filled it. You might be just trashing the memory by writing outside of the array.

Answer 1

Hello,

I think you should do this:

char inputChar = ''; //this in global
while (serial.available()) {
 inputChar = serial.read();
 if (inputChar == '2') { //Char to break
 //Do something and reset i
 } else {
 inputString[i] += inputChar; //= to +=
 }
 i++;
}