Serial monitor of IDE 2.3.6 not working with ATTiny85

Development Tools IDE 2.x
1

Hi I would like some help please if possible.
I have not been able to get the serial monitor to show data transmitted by the ATTiny85 as I need it to continue with my projects:

Arduino IDE Serial Monitor Output
Arduino IDE Serial Monitor Output1964×1080 170 KB

These are the connections between the ATtiny and the Arduino Uno:

  • Tiny physical pin 1 to Arduino pin 10
  • Tiny physical pin 5 to Arduino pin 11
  • Tiny physical pin 6 to Arduino pin 12
  • Tiny physical pin 7 to Arduino pin 13
  • Tiny physical pin 4 to Arduino pin GND
  • Tiny physical pin 8 to Arduino pin 5V
  • 10uF capacitor between Arduino Reset and Ground

This is the configuration of Arduino IDE I am using for the ATtiny85:

  • Tools > Board > ATTiny25/45/85
  • Tools > Processor ATTiny85
  • Tools > Clock > Internal 8MHz
  • Tools > Port > Com7 (Arduino Uno)
  • Tools > Port > Programmer: Arduino as ISP
  • tools > Burn Bootloader - successful

I am using Windows 10 and Arduino IDE 2.3.6.

This is what I have tried so far:

  • Cleared all wires and components from the Arduino Uno R3
  • Set the board settings to Arduino Uno; com port 7
  • Uploaded the Bare Minimum sketch to clear the board
  • Uploaded the Examples > Basics > Blink sketch to check that the board is working okay. The Built-In LED blinked regularly.
  • Uploaded a basic Arduino Serial Monitor sketch and it worked perfectly
  • Uploaded the Examples > 11.ArduinoISP > ArduinoISP sketch
  • Uploaded a basic ATTiny85 Blink sketch using Tiny physical pin 5 - successful
  • Ran the same sketch using physical pins 2 and 3 as output pins - successful each time.
  • Uploaded the sample sketch using ATTiny physical pin 3 as transmission pin.
  • Connected ATTiny physical pin 3 to Arduino RX / 0 - just a continuous line of "?". The baud is the same in the sketch and serial monitor and the TX LED on the Arduino is flashing regularly.
  • Swapped USB cables.
  • Swapped Arduinos.
  • Changing the baud rate, up or down, only changes the character displayed.

I think I have proved the Arduino Uno is okay and the ATTiny85 is okay and that I am using the correct Transmit / Receive pins.

I have tried many different sketches from many different sources and keep getting the same result.

Does anyone have any ideas please?

Here is the sketch:

#include <SoftwareSerial.h>

#define RX 3   //Receive  using ATTiny digital pin 3 / physical pin 2
#define TX 4   //Transmit using ATTiny digital pin 4 / physical pin 3

const int kpinLed = 0;  //Physical pin 5 on Tiny

//Set up a SoftwareSerial object
SoftwareSerial mySerial(RX, TX); //(Target MCU: ATtiny digital pin PB3, physical pin 2; digital pin PB4, physical pin 3)

void setup() {
  //Set the baud rate for the SoftwareSerial object
  mySerial.begin(9600);

  pinMode(kpinLed, OUTPUT);  //Set ATTiny physical pin 5, digital pin d0 as output

  mySerial.println("Initializing...");
  
  digitalWrite(kpinLed, HIGH);
  delay(1000);
  digitalWrite(kpinLed, LOW);

  mySerial.println("Setup complete");
}//end setup

void loop() { 
  mySerial.println("Hello World");
  digitalWrite(kpinLed, HIGH);
  delay(2000);
  digitalWrite(kpinLed,LOW);
  delay(2000);
}//end loop

Thank you in advance to all those taking the trouble to respond.

2

I'm not very familiar with the ATtiny

Did the LED blink at the correct rate?
Which board package are you using?

3

You have posted before but somehow have forgotten the rukles. No screenshots, no links. Post all the actual code used in code tags. Post any verbose output also in code tags. Take a legible photo of a hand drawn labelled drawing of your actual wiring, NOT the instructions.
Tell us what you expected and what actually happened.

4

maybe, if I read everything correctly..
once you have uploaded to the attiny..
disconnect everything from the uno and upload a basic proxy sketch to it..
something like this..

void setup()
{
   Serial.begin(9600);
}

void loop()
{
  if(Serial.available())
  {
    Serial.print(char(Serial.read()));
  }
}

then hook up the attiny to the uno and hopefully it works better..

good luck.. ~q

5

Thank you for getting back to me. The sketch is uploading to the ATTiny okay and it is doing what it is supposed to do. The issue is that I cannot get useable information on the serial monitor. I have since done a loop back test on the Arduino and didn't get anything back so it looks like the RX side is u/s although using the serial monitor from the Arduino is okay. Is it possible to use an alternative I/O port for Receive instead of the RX / 0. If so, how do I configure the Arduino to accept it? I am using the Arduino Uno R3. Thank you again for your help.