summaryrefslogtreecommitdiff
path: root/src/display.cc
blob: 0f7a56a63d047aaa10b5f0186bb492d00ffb5b82 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*
 * Copyright (C) 2016 by Daniel Friesel
 *
 * License: You may use, redistribute and/or modify this file under the terms
 * of either:
 * * The GNU LGPL v3 (see COPYING and COPYING.LESSER), or
 * * The 3-clause BSD License (see COPYING.BSD)
 *
 */

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <stdlib.h>

#include "display.h"
#include "font.h"
#include "storage.h"

Display display;

Display::Display()
{
	char_pos = -1;
}

void Display::disable()
{
	TIMSK0 &= ~_BV(TOIE0);
	PORTB = 0;
	PORTD = 0;
}

void Display::enable()
{
	// Ports B and D drive the dot matrix display -> set all as output
	DDRB = 0xff;
	DDRD = 0xff;

	// Enable 8bit counter with prescaler=8 (-> timer frequency = 1MHz)
	TCCR0A = _BV(CS01);
	// raise timer interrupt on counter overflow (-> interrupt frequency = ~4kHz)
	TIMSK0 = _BV(TOIE0);
}

void Display::multiplex()
{
	/*
	 * To avoid flickering, do not put any code (or expensive index
	 * calculations) between the following three lines.
	 */
	PORTB = 0;
	PORTD = disp_buf[active_col];
	PORTB = _BV(active_col);

	if (++active_col == 8) {
		active_col = 0;
		if (++update_cnt == update_threshold) {
			update_cnt = 0;
			need_update = 1;
		}
	}
}

void Display::update() {
	uint8_t i, glyph_len;
	uint8_t *glyph_addr;
	if (need_update) {
		need_update = 0;

		if (status == RUNNING) {
			if (current_anim->type == AnimationType::TEXT) {
				if (current_anim->direction == 0) {
					for (i = 0; i < 7; i++) {
						disp_buf[i] = disp_buf[i+1];
					}
				} else if (current_anim->direction == 1) {
					for (i = 7; i > 0; i--) {
						disp_buf[i] = disp_buf[i-1];
					}
				}

				glyph_addr = (uint8_t *)pgm_read_ptr(&font[current_anim->data[str_pos]]);
				glyph_len = pgm_read_byte(&glyph_addr[0]);
				char_pos++;

				if (char_pos > glyph_len) {
					char_pos = 0;
					if (current_anim->direction == 0)
						str_pos++;
					else
						str_pos--;
				}

				if (current_anim->direction == 0) {
					if (char_pos == 0) {
						disp_buf[7] = 0xff; // whitespace
					} else {
						disp_buf[7] = ~pgm_read_byte(&glyph_addr[char_pos]);
					}
				} else {
					if (char_pos == 0) {
						disp_buf[0] = 0xff; // whitespace
					} else {
						disp_buf[0] = ~pgm_read_byte(&glyph_addr[glyph_len - char_pos + 1]);
					}
				}

			} else if (current_anim->type == AnimationType::FRAMES) {
				for (i = 0; i < 8; i++) {
					disp_buf[i] = ~current_anim->data[str_pos+i];
				}
				str_pos += 8;
			}
			if (current_anim->direction == 0) {
				if ((str_chunk == ((current_anim->length - 1) / 128))
						&& (str_pos > ((current_anim->length - 1) % 128))) {
					str_chunk = 0;
					str_pos = 0;
					if (current_anim->delay > 0) {
						status = PAUSED;
						update_threshold = 244;
					}
					if (current_anim->length > 128) {
						storage.loadChunk(str_chunk, current_anim->data);
					}
				} else if ((current_anim->length > 128) && (str_pos >= 128)) {
					str_pos = 0;
					str_chunk++;
					storage.loadChunk(str_chunk, current_anim->data);
				}
			} else {
				if (str_pos >= 128) {
					if (str_chunk == 0) {
						if (current_anim->length > 128) {
							str_chunk = (current_anim->length - 1) / 128;
							storage.loadChunk(str_chunk, current_anim->data);
						}
						if (current_anim->delay > 0) {
							str_pos = 0;
							status = PAUSED;
							update_threshold = 244;
						} else {
							str_pos = (current_anim->length - 1) % 128;
						}
					} else {
						str_chunk--;
						storage.loadChunk(str_chunk, current_anim->data);
						str_pos = 127;
					}
				}
			}
		} else if (status == PAUSED) {
			str_pos++;
			if (str_pos >= current_anim->delay) {
				if (current_anim->direction == 0)
					str_pos = 0;
				else if (current_anim->length <= 128)
					str_pos = current_anim->length - 1;
				else
					str_pos = 127;
				status = RUNNING;
				update_threshold = current_anim->speed;
			}
		}
	}
}

void Display::reset()
{
	for (uint8_t i = 0; i < 8; i++)
		disp_buf[i] = 0xff;
	update_cnt = 0;
	str_pos = 0;
	str_chunk = 0;
	char_pos = -1;
	need_update = 1;
	status = RUNNING;
}

void Display::show(animation_t *anim)
{
	current_anim = anim;
	reset();
	update_threshold = current_anim->speed;
	if (current_anim->direction == 1) {
		if (current_anim->length > 128) {
			str_chunk = (current_anim->length - 1) / 128;
			storage.loadChunk(str_chunk, current_anim->data);
		}
		str_pos = (current_anim->length - 1) % 128;
	}
}

/*
 * Current configuration:
 * One interrupt per 256 microseconds. The whole display is refreshed every
 * 2048us, giving a refresh rate of ~500Hz
 */
ISR(TIMER0_OVF_vect)
{
	display.multiplex();
}