Cleaned up the licensing.

third_party/mozc-flap/flap.c

@@ -0,0 +1,217 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA  02110-1301, USA.
+ */
+
+
+/*
+ * USB keyboard with a split flap display.
+ *
+ * PB0 through PB3: unipolar stepper motor control signals
+ *  PB0 A
+ *  PB1 ~A
+ *  PB2 B
+ *  PB3 ~B
+ *
+ * PB6: normally-open push switch for zero-position adjustment.
+ * PB7: normally-open push switch for the input UI.
+ */
+
+#include <avr/io.h>
+#include <avr/wdt.h>
+#include <util/delay.h>     /* for _delay_ms() */
+#include "usb_keyboard.h"
+
+// Number of flaps that appear in one cycle.
+#define LETTERS 40
+
+// Number of flaps for alphabets and numerical digits.
+#define ALPHANUMERICS (26 + 10)
+const uchar extra_character_keycodes[LETTERS - ALPHANUMERICS] = {
+  KEYCODE_HYPHEN, KEYCODE_COMMA, KEYCODE_PERIOD, KEYCODE_SPACE
+};
+
+#define IDLE_TIMER_FREQUENCY 100
+#define DELAY_BEFORE_INPUT (1 * IDLE_TIMER_FREQUENCY)
+#define MAX_SPEED 9
+
+#ifdef _FULL_STEP
+
+#define STEPPER_PHASES 4
+/* Stepper excitation pattern. Invert the order if necessary.
+ * Bits 7 and 6 must be set to enable internal pullups for the switches.
+ */
+const uchar stepper_pattern[STEPPER_PHASES] = {0xc1, 0xc4, 0xc2, 0xc8};
+#define STEPPER_PHASE_MASK 3
+#define STEPS_PER_LETTER 5
+
+#else
+
+/* half-step mode */
+#define STEPPER_PHASES 8
+const uchar stepper_pattern[STEPPER_PHASES] = {
+    0xc1, 0xc5, 0xc4, 0xc6, 0xc2, 0xca, 0xc8, 0xc9};
+#define STEPPER_PHASE_MASK 7
+#define STEPS_PER_LETTER 10
+
+#endif
+
+#define button_pressed() bit_is_clear(PINB, PINB7)
+#define adjust_button_pressed() bit_is_clear(PINB, PINB6)
+
+const unsigned int intervals[MAX_SPEED + 1] = {
+  (unsigned int)(F_CPU / 8 / IDLE_TIMER_FREQUENCY),
+  (unsigned int)(F_CPU / 8 / 25),
+  (unsigned int)(F_CPU / 8 / 43),
+  (unsigned int)(F_CPU / 8 / 56),
+  (unsigned int)(F_CPU / 8 / 66),
+  (unsigned int)(F_CPU / 8 / 75),
+  (unsigned int)(F_CPU / 8 / 82),
+  (unsigned int)(F_CPU / 8 / 90),
+  (unsigned int)(F_CPU / 8 / 97),
+  (unsigned int)(F_CPU / 8 / 103)
+};
+
+uchar stepper_phase = 0;
+
+void advance_stepper_phase() {
+#ifdef STEPPER_PHASE_MASK
+  stepper_phase = (stepper_phase + 1) & STEPPER_PHASE_MASK;
+#else
+  stepper_phase ++;
+  if (stepper_phase >= STEPPER_PHASES) {
+      stepper_phase = 0;
+  }
+#endif
+  PORTB = stepper_pattern[stepper_phase];
+}
+
+int __attribute__((noreturn)) main(void)
+{
+  DDRB = 0x3f;
+  PORTB = stepper_pattern[stepper_phase];
+
+  wdt_enable(WDTO_1S);
+
+  initUsbKeyboard();
+
+  uchar key = 0;
+  uchar lastKey = 0;
+
+  uchar character = 0;
+  uchar substep = 0;
+  uchar stop_count = 0;
+  uchar speed = 0;
+  enum {INIT, ACTIVE, PAUSED, ADJUST};
+  uchar state = INIT;
+  uchar on_count = 0;
+
+  /* sets up timer for stepper interval */
+  /* timer 1 CTC mode, counts up at f[clock]/8 [Hz] */
+  TCCR1B = (1 << WGM12) | (1 << CS11);
+  TCNT1 = 0;
+  OCR1A = intervals[speed];
+
+  while(1) {
+    wdt_reset();
+    usbPoll();
+
+    if (bit_is_clear(TIFR, OCF1A)) {
+      continue;
+    }
+    TIFR |= _BV(OCF1A);  /* clear OCF1A */
+
+    switch(state) {
+    case ADJUST:
+      speed = 0;
+      if (adjust_button_pressed()) {
+      } else {
+        state = INIT;
+      }
+      break;
+    case INIT:
+      if (button_pressed()) {
+        speed = 1;
+        on_count = 0;
+        state = ACTIVE;
+      }
+      if (adjust_button_pressed()) {
+        state = ADJUST;
+        advance_stepper_phase();
+        continue;
+      }
+      break;
+    case ACTIVE:
+      if (button_pressed()) {
+        if (on_count < STEPS_PER_LETTER) {
+          on_count ++;
+        } else if (speed < MAX_SPEED) {
+          speed ++;
+        }
+      } else {
+        if (speed > 1) {
+          speed --;
+        } else if (speed == 1) {
+          if (substep == 0) {
+            speed = 0;
+            stop_count = 0;
+            state = PAUSED;
+          }
+        }
+      }
+      break;
+    case PAUSED:
+    default:
+      if (button_pressed()) {
+        speed = 1;
+        state = ACTIVE;
+      } else {
+        if (stop_count == DELAY_BEFORE_INPUT) {
+          if (character >= ALPHANUMERICS) {
+            key = extra_character_keycodes[character - ALPHANUMERICS];
+          } else {
+            key = KEYCODE_A + character;
+          }
+          state = INIT;
+        } else {
+          stop_count ++;
+        }
+      }
+    }
+
+    OCR1A = intervals[speed];
+    if (speed > 0) {
+      substep ++;
+      if (substep >= STEPS_PER_LETTER) {
+        substep = 0;
+        character ++;
+        if (character >= LETTERS) {
+          character = 0;
+        }
+      }
+      advance_stepper_phase();
+    }
+
+    if (usbInterruptIsReady()) {
+      if (key != lastKey) {
+        lastKey = key;
+        prepareInterruptReport(key);
+        key = KEYCODE_NONE;
+      }
+    }
+  }
+}