Started following some tutorial on att85 usi. Downloaded example code from make avr book.

Make AVR Examples/Chapter04_Bit-Twiddling/cylonEyes_halfStepping/cylonEyes_halfStepping.c

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+/* Cylon Eyes
+   Half-stepping turns the next light on for a little bit,
+   makes the pattern visually smoother, improves overall
+   cylonity.
+*/
+
+// ------- Preamble -------- //
+#include <avr/io.h>                        /* Defines pins, ports, etc */
+#include <util/delay.h>                     /* Functions to waste time */
+
+#define DELAYTIME 85    /* milliseconds, 50-75 is good for smooth eyes */
+
+int main(void) {
+
+  // -------- Inits --------- //
+  uint8_t i;
+  DDRB = 0xff;                  /* Data Direction Register B:
+                                   all set up for output */
+
+  // ------ Event loop ------ //
+  while (1) {                                              /* mainloop */
+
+    for (i = 0; i < 7; i++) {                   /* count i from 0 to 6 */
+      PORTB |= (1 << i);                              /* turn on led i */
+      _delay_ms(DELAYTIME);                                    /* wait */
+
+      PORTB |= (1 << (i + 1));                 /* turn the next led on */
+      _delay_ms(DELAYTIME / 2);
+
+      PORTB &= ~(1 << i);                            /* turn off led i */
+    }
+
+    for (i = 7; i > 0; i--) {                   /* count i from 7 to 1 */
+      PORTB |= (1 << i);
+      _delay_ms(DELAYTIME);
+
+      PORTB |= (1 << (i - 1));                 /* turn the next led on */
+      _delay_ms(DELAYTIME / 2);
+
+      PORTB &= ~(1 << i);                            /* turn off led i */
+    }
+
+  }                                                  /* End event loop */
+  return 0;
+}                                                          /* end main */