mklove 💖

...not war 💔

Here lays the code for ATiny85 that powers mklove - cute little LED heart

It is based on Digistump usb-capable board - not just pure ATtiny

Many parts of the code are heavily reliant on many hardware modifications that I've done on Digistump pcb board. Some examples:

• detecting whether device is currently charging is possible thanks to re-soldering the R3 pull-up resistor
• ...and this was possible by de-soldering D3 diode that was connecting USB with VCC

If you would ever want to re-create it yourself, or just read into the story of creating it, you can do it on my blog ^_^

https://the.lastgimbus.com/blog/crafting-battery-powered-thingy-with-attiny85

Code details

Thanks to my expertise with Flutter 😌😌😌 I've learned a lot about state management - and thus, the main void loop() {} is running always-and-smooth - without excessive use of delay()

// ONLY ONE part that uses blocking delay() is "charging started" animation, because I didn't have idea nor flash memory (xD) to do this otherwise

Everything else is done with global variables that hold state. You modify those variables, and then loop() will take care of rest.

Time-based things are done with progress concept. If you want a blink, instead of doing:

void loop(){
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
}

You do:

void blink(uint8_t progress){
    if (progress > (255/2)) digitalWrite(LED_BUILTIN, HIGH);
    else digitalWrite(LED_BUILTIN, LOW);
}

void loop() {
    blink(millis() % 255);
    // You could also divide or multiply millis() to slow down or speed up the animation:
    blink((millis() / 10) % 255);
}

The EasyButton library really helped with this! https://github.com/evert-arias/EasyButton