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
|
# Support for ST7920 (128x64 graphics) LCD displays
#
# Copyright (C) 2018 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging
import font8x14
BACKGROUND_PRIORITY_CLOCK = 0x7fffffff00000000
# Spec says 72us, but faster is possible in practice
ST7920_CMD_DELAY = .000020
ST7920_SYNC_DELAY = .000045
TextGlyphs = { 'right_arrow': '\x1a' }
CharGlyphs = { 'degrees': bytearray(font8x14.VGA_FONT[0xf8]) }
class ST7920:
def __init__(self, config):
printer = config.get_printer()
# pin config
ppins = printer.lookup_object('pins')
pins = [ppins.lookup_pin(config.get(name + '_pin'))
for name in ['cs', 'sclk', 'sid']]
mcu = None
for pin_params in pins:
if mcu is not None and pin_params['chip'] != mcu:
raise ppins.error("st7920 all pins must be on same mcu")
mcu = pin_params['chip']
self.pins = [pin_params['pin'] for pin_params in pins]
self.mcu = mcu
self.oid = self.mcu.create_oid()
self.mcu.register_config_callback(self.build_config)
self.send_data_cmd = self.send_cmds_cmd = None
self.is_extended = False
# framebuffers
self.text_framebuffer = bytearray(' '*64)
self.glyph_framebuffer = bytearray(128)
self.graphics_framebuffers = [bytearray(32) for i in range(32)]
self.all_framebuffers = [
# Text framebuffer
(self.text_framebuffer, bytearray('~'*64), 0x80),
# Glyph framebuffer
(self.glyph_framebuffer, bytearray('~'*128), 0x40),
# Graphics framebuffers
] + [(self.graphics_framebuffers[i], bytearray('~'*32), i)
for i in range(32)]
self.cached_glyphs = {}
self.icons = {}
def build_config(self):
self.mcu.add_config_cmd(
"config_st7920 oid=%u cs_pin=%s sclk_pin=%s sid_pin=%s"
" sync_delay_ticks=%d cmd_delay_ticks=%d" % (
self.oid, self.pins[0], self.pins[1], self.pins[2],
self.mcu.seconds_to_clock(ST7920_SYNC_DELAY),
self.mcu.seconds_to_clock(ST7920_CMD_DELAY)))
cmd_queue = self.mcu.alloc_command_queue()
self.send_cmds_cmd = self.mcu.lookup_command(
"st7920_send_cmds oid=%c cmds=%*s", cq=cmd_queue)
self.send_data_cmd = self.mcu.lookup_command(
"st7920_send_data oid=%c data=%*s", cq=cmd_queue)
def send(self, cmds, is_data=False, is_extended=False):
cmd_type = self.send_cmds_cmd
if is_data:
cmd_type = self.send_data_cmd
elif self.is_extended != is_extended:
add_cmd = 0x22
if is_extended:
add_cmd = 0x26
cmds = [add_cmd] + cmds
self.is_extended = is_extended
cmd_type.send([self.oid, cmds], reqclock=BACKGROUND_PRIORITY_CLOCK)
#logging.debug("st7920 %d %s", is_data, repr(cmds))
def flush(self):
# Find all differences in the framebuffers and send them to the chip
for new_data, old_data, fb_id in self.all_framebuffers:
if new_data == old_data:
continue
# Find the position of all changed bytes in this framebuffer
diffs = [[i, 1] for i, (n, o) in enumerate(zip(new_data, old_data))
if n != o]
# Batch together changes that are close to each other
for i in range(len(diffs)-2, -1, -1):
pos, count = diffs[i]
nextpos, nextcount = diffs[i+1]
if pos + 5 >= nextpos and nextcount < 16:
diffs[i][1] = nextcount + (nextpos - pos)
del diffs[i+1]
# Transmit changes
for pos, count in diffs:
count += pos & 0x01
count += count & 0x01
pos = pos & ~0x01
chip_pos = pos >> 1
if fb_id < 0x40:
# Graphics framebuffer update
self.send([0x80 + fb_id, 0x80 + chip_pos], is_extended=True)
else:
self.send([fb_id + chip_pos])
self.send(new_data[pos:pos+count], is_data=True)
old_data[:] = new_data
def init(self):
cmds = [0x24, # Enter extended mode
0x40, # Clear vertical scroll address
0x02, # Enable CGRAM access
0x26, # Enable graphics
0x22, # Leave extended mode
0x02, # Home the display
0x06, # Set positive update direction
0x0c] # Enable display and hide cursor
self.send(cmds)
self.flush()
def cache_glyph(self, glyph_name, base_glyph_name, glyph_id):
icon = self.icons.get(glyph_name)
base_icon = self.icons.get(base_glyph_name)
if icon is None or base_icon is None:
return
for i, (bits, base_bits) in enumerate(zip(icon, base_icon)):
pos = glyph_id*32 + i*2
b1, b2 = (bits >> 8) & 0xff, bits & 0xff
b1, b2 = b1 ^ (base_bits >> 8) & 0xff, b2 ^ base_bits & 0xff
self.glyph_framebuffer[pos:pos+2] = [b1, b2]
self.all_framebuffers[1][1][pos:pos+2] = [b1 ^ 1, b2 ^ 1]
self.cached_glyphs[glyph_name] = (base_glyph_name, (0, glyph_id*2))
def write_text(self, x, y, data):
if x + len(data) > 16:
data = data[:16 - min(x, 16)]
pos = [0, 32, 16, 48][y] + x
self.text_framebuffer[pos:pos+len(data)] = data
def write_graphics(self, x, y, row, data):
if x + len(data) > 16:
data = data[:16 - min(x, 16)]
gfx_fb = y * 16 + row
if gfx_fb >= 32:
gfx_fb -= 32
x += 16
self.graphics_framebuffers[gfx_fb][x:x+len(data)] = data
def set_glyphs(self, glyphs):
for glyph_name, glyph_data in glyphs.items():
data = glyph_data.get('icon16x16')
if data is not None:
self.icons[glyph_name] = data
# Setup animated glyphs
self.cache_glyph('fan2', 'fan1', 0)
self.cache_glyph('bed_heat2', 'bed_heat1', 1)
def write_glyph(self, x, y, glyph_name):
glyph_id = self.cached_glyphs.get(glyph_name)
if glyph_id is not None and x & 1 == 0:
# Render cached icon using character generator
glyph_name = glyph_id[0]
self.write_text(x, y, glyph_id[1])
icon = self.icons.get(glyph_name)
if icon is not None:
# Draw icon in graphics mode
for i, bits in enumerate(icon):
self.write_graphics(x, y, i, [(bits >> 8) & 0xff, bits & 0xff])
return 2
char = TextGlyphs.get(glyph_name)
if char is not None:
# Draw character
self.write_text(x, y, char)
return 1
font = CharGlyphs.get(glyph_name)
if font is not None:
# Draw single width character
for i, bits in enumerate(font):
self.write_graphics(x, y, i, [bits])
return 1
return 0
def clear(self):
self.text_framebuffer[:] = ' '*64
zeros = bytearray(32)
for gfb in self.graphics_framebuffers:
gfb[:] = zeros
def get_dimensions(self):
return (16, 4)
|
