Add arduino (led) version

klock4.ino

@@ -0,0 +1,125 @@
+#include <FastLED.h>
+#define DATA_PIN 13
+
+#include <stdint.h>
+#include <time.h>
+#include <math.h>
+
+#define ROWS 10
+#define COLS 11
+
+typedef struct {uint8_t start; uint16_t len;} word_t;
+
+#define ES        ((word_t) {.start=  0, .len=2})
+#define IST       ((word_t) {.start=  3, .len=3})
+#define FUNF_PRE  ((word_t) {.start=  7, .len=4})
+#define ZEHN_PRE  ((word_t) {.start= 11, .len=4})
+#define ZWANZIG   ((word_t) {.start= 15, .len=7})
+#define VIERTEL   ((word_t) {.start= 26, .len=7})
+#define VOR       ((word_t) {.start= 33, .len=3})
+#define NACH      ((word_t) {.start= 40, .len=4})
+#define HALB      ((word_t) {.start= 44, .len=4})
+#define ELF       ((word_t) {.start= 49, .len=3})
+#define FUNF_UHR  ((word_t) {.start= 51, .len=4})
+#define EINS      ((word_t) {.start= 55, .len=4})
+#define ZWEI      ((word_t) {.start= 62, .len=4})
+#define DREI      ((word_t) {.start= 66, .len=4})
+#define VIER      ((word_t) {.start= 73, .len=4})
+#define SECHS     ((word_t) {.start= 77, .len=5})
+#define ACHT      ((word_t) {.start= 84, .len=4})
+#define SIEBEN    ((word_t) {.start= 88, .len=6})
+#define ZWOLF     ((word_t) {.start= 94, .len=5})
+#define ZEHN_UHR  ((word_t) {.start= 99, .len=4})
+#define NEUN      ((word_t) {.start=102, .len=4})
+#define UHR       ((word_t) {.start=107, .len=3})
+
+word_t HOURS[] = {
+  ZWOLF, EINS, ZWEI, DREI, VIER, FUNF_UHR,
+  SECHS, SIEBEN, ACHT, NEUN, ZEHN_UHR, ELF
+};
+word_t PARTS[] = {
+  UHR, FUNF_PRE, ZEHN_PRE, VIERTEL,
+  ZWANZIG, FUNF_PRE, HALB
+};
+
+
+CRGB leds[ROWS*COLS];
+
+void set(word_t word) {
+  CRGB color = CRGB(255,255,255);
+  int dir = 1;
+  // because of the snaking LED layout, we need to reverse every second row
+  // i.e. flip the start on the other side and then count backwards
+  if (word.start % 22 >= 11) {
+    word.start = (word.start/11)*11 + 10 - (word.start % 11);
+    dir = -1;
+  }
+  for (unsigned int i = 0; i < word.len; i++)
+    leds[word.start + dir*i] = color;
+}
+
+void reset(void) {
+  memset(&leds, 0, sizeof(leds));
+  set(ES);
+  set(IST);
+}
+
+
+void settime(time_t ts) {
+
+  unsigned int second = ts % 60;
+
+  unsigned int minute = (ts / 60) % 60;
+  float fminute = (float) minute + (float) second / 60;
+  minute = 5 * (unsigned int) roundf(fminute / 5);
+
+  unsigned int timezone = 1;
+  unsigned int daylight_savings = 1;
+  unsigned int hour   = (ts / (60*60) + timezone + daylight_savings) % 12;
+
+  int before = 0;
+
+  if (minute >= 25) {
+    hour = (hour+1) % 12;
+    before = 1;
+    minute = 60-minute;
+    if (minute == 35) {
+      minute = 25;
+      before = 0;
+    }
+  }
+
+  if (minute == 25)
+    before = !before;
+
+  reset();
+
+  if (minute != 0 && minute != 30)
+    set(before ? VOR : NACH);
+
+  set(HOURS[hour]);
+  set(PARTS[minute/5]);
+
+  if (minute/5 == 5)
+    set(HALB); // '5 before half' requires additional set
+
+}
+
+void setup() { 
+  FastLED.addLeds<WS2812,DATA_PIN,GRB>(leds, ROWS*COLS);
+  FastLED.setBrightness(64);
+}
+
+void loop() {
+
+  // TODO: Get actual time from somewhere
+  time_t ts = 1616970481; // UTC
+
+  while (1) {
+    settime(ts);
+    FastLED.show();
+    delay(200);
+    ts += 5 * 60;
+  };
+
+}