ralphbacon / 174-attiny13-brain-dead Goto Github PK

I did watch your Youtube video about ATtiny13 + MicroCore, and I'm sorry to say I'm a bit disappointed with your conclusion. Even though MicroCore is very light-weight, the T13 is still very limited in terms of memory. However, it's a great little chip if one really wants to learn how to write efficient code!

OSCCAL:
Ralph Doncaster and I created a very nice OSCCAL sketch that uses a received x character from the serial monitor to tweak and tune the OSCCAL value. It's very reliable and works great!
You can find this sketch under Examples > Serial Examples > OscillatorCalibration in Arduino IDE if you get the latest MicroCore version.
Another thing to point out is that even though there are two internal oscillators you can still use the OSCCAL value for 9.6 MHz when running at 1.2 MHz (9.6MHz/8), and the 4.8 MHz value when running at 600 kHz (4.8MHz/8).

Serial printing:
The code you host here doesn't really use any of the built-in MicroCore UART functionality. The built-in Serial functionality is smaller and faster, especially the printNumber function. I'm pretty sure it will work like you'd expect if you use it like intended:

/*
PB0 > TX pin
PB1 > RX pin

115200 baud @ 9.6 MHz
57600 baud @ 4.8 MHz

Run the OscillatorCalibration sketch first!
*/

#include <EEPROM.h>

uint32_t counter = 0;
uint8_t small_count = 0;

void setup() 
{
  // Check if there exist any OSCCAL value in EEPROM addr. 0
  // If not, run the oscillator tuner sketch first
  uint8_t cal = EEPROM.read(0);
  if (cal < 0x80)
    OSCCAL = cal;
}

void loop() 
{
  Serial.print(F("Serial Test ")); // The F macro should be here!
  Serial.print(counter);
  Serial.println(); // Occupies only 8 bytes
  counter++;
  small_count++;
  delay(1000); // Uses _delay_ms(1) inside a while loop to prevent inlining
}

The problems Ralph Doncaster pointed out were fixed in the end. The problem was that we couldn't reduce the compiled size properly when HalfDuplexSerial inherited Print (Some Arduino builder issue I think). Instead, some of the Print functions were copied over to HalfDuplexSerial. The result is a reduced sketch size with some "backend code" that's not as elegant as I had initially hoped.