Files
0001-FireFly/firmware/ATTINY85_2026_MorseThrowie/ATTINY85_2026_MorseThrowie.ino

311 lines
13 KiB
C++

/*
=============================================================================
FireFly Morse Throwie
- a light controlled (LED as Sensor) morse blinker throwie with ATTiny85
=============================================================================
Project definitions, sources
-----------------------------------------------------------------------------
Version: 0.2 - ATTiny85, 1 MHz, BOD fuse disabled
gitea : https://gitea.togo-lab.io/tgohle/0001-FireFly
Date : 2026-06-13
-----------------------------------------------------------------------------
Inspired by Karl Lunt's FireFly project:
http://www.seanet.com/~karllunt/fireflyLED.html
Morse code reference:
'A', ".-" 'B', "-..." 'C', "-.-."
'D', "-.." 'E', "." 'F', "..-."
'G', "--." 'H', "...." 'I', ".."
'J', ".---" 'K', "-.-" 'L', ".-.."
'M', "--" 'N', "-." 'O', "---"
'P', ".--." 'Q', "--.-" 'R', ".-."
'S', "..." 'T', "-" 'U', "..-"
'V', "...-" 'W', ".--" 'X', "-..-"
'Y', "-.--" 'Z', "--.."
'1', ".----" '2', "..---" '3', "...--"
'4', "....-" '5', "....." '6', "-...."
'7', "--..." '8', "---.." '9', "----."
'0', "-----"
'.', ".-.-.-" ',', "--..--" '?', "..--.."
'!', "-.-.--" ':', "---..." ';', "-.-.-."
'(', "-.--." ')', "-.--.-" '"', ".-..-."
'@', ".--.-." '&', ".-..."
Legal stuff / Copyright:
License_-_CC_BY-NC_4.0
https://creativecommons.org/licenses/by-nc/4.0/
-----------------------------------------------------------------------------
*/
#include <avr/sleep.h>
#include <avr/wdt.h>
#include <avr/pgmspace.h> // FIX 3: needed for PROGMEM / pgm_read_byte
#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif
// ---------------------------------------------------------------------------
// Timing: unit length in ms.
// At 1 MHz, delay() is accurate when F_CPU=1000000L is set in boards.txt.
// 100 ms gives readable optical Morse; raise to 150 if readability is poor.
#define unitLength 100
// ---------------------------------------------------------------------------
// LED pin definitions (N-side = cathode, P-side = anode for sensing/driving)
#define LED1_N_SIDE 3
#define LED1_P_SIDE 4
// ---------------------------------------------------------------------------
// ATTiny85 has 512 bytes SRAM; this frees all of it for the stack.
// Only uppercase letters, digits, and the special chars in the switch below.
// Test only: 20 x "0" due 0 = "-----" most energy draining
const char morseText[] PROGMEM = "0000000000000000000";
// Ruler: 0...0....1...1....2 Attention: more Text
// Ruler: 1...5....0...5....0 will cost more power!
// ---------------------------------------------------------------------------
// Darkness threshold.
// Higher value = triggers in brighter conditions.
// Best calibrated at actual dusk/dawn with the chosen LED type.
unsigned int darknessThreshold = 17000;
// ---------------------------------------------------------------------------
// Watchdog interrupt flag — volatile because it is written in an ISR
volatile boolean f_wdt = 1;
// ---------------------------------------------------------------------------
// Forward declarations
void setup_watchdog(int ii);
void system_sleep();
unsigned int sensDarkness(int LED_N, int LED_P);
void morse(int LED_N, int LED_P);
void dit(int LED_P);
void dah(int LED_P);
// ===========================================================================
// Setup
// ===========================================================================
void setup()
{
// Disable unused peripherals immediately to save some µ/mA.
// PRTIM1, PRUSI: genuinely unused, safe to gate off
// PRADC: controlled manually around sensDarkness()
// PRTIM0: must stay ON — delay() and millis() depend on Timer0
PRR = (1 << PRTIM1) | (1 << PRUSI) | (1 << PRADC);
// ADC is gated via PRR above; also clear ADEN just in case
cbi(ADCSRA, ADEN);
setup_watchdog(9); // 8-second watchdog interval
// simple repeat if more delay is need, eg 4
}
// ===========================================================================
// Main loop
// ===========================================================================
void loop()
{
if (f_wdt == 1) {
f_wdt = 0;
// Enable ADC only for the sensing window, then shut it off again.
cbi(PRR, PRADC); // un-gate ADC clock
sbi(ADCSRA, ADEN); // power ADC on
if (sensDarkness(LED1_N_SIDE, LED1_P_SIDE) > darknessThreshold) {
morse(LED1_N_SIDE, LED1_P_SIDE);
}
cbi(ADCSRA, ADEN); // ADC off
sbi(PRR, PRADC); // re-gate ADC clock
// Return LED pins to input (high-Z) before sleeping
pinMode(LED1_N_SIDE, INPUT);
pinMode(LED1_P_SIDE, INPUT);
}
// sleep 4 x 8 s = ~32 s between activations
for (uint8_t i = 0; i < 1; i++) {
system_sleep();
}
// f_wdt is set to 1 by the WDT ISR when the 8 s expire; no manual clear needed here.
}
// ===========================================================================
// Sleep helpers
// ===========================================================================
void system_sleep()
{
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
sleep_enable();
sleep_mode(); // CPU halts here until WDT fires
sleep_disable();
// ADC stays off - re-enable it in loop() only when sensing
}
// Watchdog setup - ii selects timeout:
// 0=16ms 1=32ms 2=64ms 3=128ms 4=250ms 5=500ms
// 6=1s 7=2s 8=4s 9=8s
void setup_watchdog(int ii)
{
byte bb;
if (ii > 9) ii = 9;
bb = ii & 7;
if (ii > 7) bb |= (1 << 5);
bb |= (1 << WDCE);
MCUSR &= ~(1 << WDRF);
WDTCR |= (1 << WDCE) | (1 << WDE); // timed sequence - must not be split
WDTCR = bb;
WDTCR |= _BV(WDIE);
}
ISR(WDT_vect)
{
f_wdt = 1;
}
// ===========================================================================
// Light sensor
// ===========================================================================
// Returns a "darkness level": higher = darker.
// Charges the LED junction capacitor, then times how long it takes to bleed
// back through the reverse-biased diode to a logic LOW.
// ~30000 = pitch black, ~0 = bright light
// return type is unsigned int (counter can reach 30000, fits in 16 bits)
unsigned int sensDarkness(int LED_N, int LED_P)
{
unsigned int i;
// Charge the LED (forward-bias momentarily)
pinMode(LED_N, OUTPUT);
pinMode(LED_P, OUTPUT);
digitalWrite(LED_N, HIGH);
digitalWrite(LED_P, LOW);
// Let the N-end float and measure bleed-down time
pinMode(LED_N, INPUT);
digitalWrite(LED_N, LOW); // disable internal pull-up
for (i = 0; i < 30000; i++) {
if (digitalRead(LED_N) == 0) break;
}
// clean up after sensing
pinMode(LED_N, OUTPUT);
digitalWrite(LED_N, LOW);
pinMode(LED_P, OUTPUT);
digitalWrite(LED_P, LOW);
return i;
}
// ===========================================================================
// Morse helpers
// ===========================================================================
void dit(int LED_P)
{
digitalWrite(LED_P, HIGH); delay(unitLength);
digitalWrite(LED_P, LOW); delay(unitLength);
}
void dah(int LED_P)
{
digitalWrite(LED_P, HIGH); delay(unitLength * 3);
digitalWrite(LED_P, LOW); delay(unitLength);
}
// ===========================================================================
// Morse sender
// ===========================================================================
void morse(int LED_N, int LED_P)
{
pinMode(LED_N, OUTPUT);
pinMode(LED_P, OUTPUT);
digitalWrite(LED_N, LOW);
// read each character from flash with pgm_read_byte()
// use < morseText length, not <= (avoids reading past the null terminator)
uint8_t len = strlen_P(morseText);
for (uint8_t i = 0; i < len; i++)
{
char c = (char)pgm_read_byte(&morseText[i]);
switch (c)
{
// ----- Letters -----
case 'A': dit(LED_P); dah(LED_P); break; // .-
case 'B': dah(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // -...
case 'C': dah(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); break; // -.-.
case 'D': dah(LED_P); dit(LED_P); dit(LED_P); break; // -..
case 'E': dit(LED_P); break; // .
case 'F': dit(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); break; // ..-.
case 'G': dah(LED_P); dah(LED_P); dit(LED_P); break; // --.
case 'H': dit(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // ....
case 'I': dit(LED_P); dit(LED_P); break; // ..
case 'J': dit(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); break; // .---
case 'K': dah(LED_P); dit(LED_P); dah(LED_P); break; // -.-
case 'L': dit(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); break; // .-..
case 'M': dah(LED_P); dah(LED_P); break; // --
case 'N': dah(LED_P); dit(LED_P); break; // -.
case 'O': dah(LED_P); dah(LED_P); dah(LED_P); break; // ---
case 'P': dit(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); break; // .--.
case 'Q': dah(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); break; // --.-
case 'R': dit(LED_P); dah(LED_P); dit(LED_P); break; // .-.
case 'S': dit(LED_P); dit(LED_P); dit(LED_P); break; // ...
case 'T': dah(LED_P); break; // -
case 'U': dit(LED_P); dit(LED_P); dah(LED_P); break; // ..-
case 'V': dit(LED_P); dit(LED_P); dit(LED_P); dah(LED_P); break; // ...-
case 'W': dit(LED_P); dah(LED_P); dah(LED_P); break; // .--
case 'X': dah(LED_P); dit(LED_P); dit(LED_P); dah(LED_P); break; // -..-
case 'Y': dah(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); break; // -.--
case 'Z': dah(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); break; // --..
// ----- Digits -----
case '1': dit(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); break; // .----
case '2': dit(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); break; // ..---
case '3': dit(LED_P); dit(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); break; // ...--
case '4': dit(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); dah(LED_P); break; // ....-
case '5': dit(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // .....
case '6': dah(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // -....
case '7': dah(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // --...
case '8': dah(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); break; // ---.
case '9': dah(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); break; // ----.
case '0': dah(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); dah(LED_P); break; // -----
// ----- Punctuation -----
case ' ': delay(unitLength * 5); break; // word gap (5 + 3 = 8 units total)
case '.': dit(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); break; // .-.-.-
case ',': dah(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); break; // --..--
case '?': dit(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); break; // ..--..
case '!': dah(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); break; // -.-.--
case ':': dah(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // ---...
case ';': dah(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); break; // -.-.-.
case '(': dah(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); break; // -.--.
case ')': dah(LED_P); dit(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); break; // -.--.-
case '"': dit(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); break; // .-..-.
case '@': dit(LED_P); dah(LED_P); dah(LED_P); dit(LED_P); dah(LED_P); dit(LED_P); break; // .--.-.
case '&': dit(LED_P); dah(LED_P); dit(LED_P); dit(LED_P); dit(LED_P); break; // .-...
}
// Inter-character gap: 3 units (the dit/dah functions already trail 1 unit,
// so this adds the remaining 2 to reach the standard 3-unit gap).
// Space case already handles word gap - no extra delay needed there.
if (c != ' ') {
delay(unitLength * 2);
}
}
}