klipper-dgus/klippy/extras/display/hd44780.py

123 lines
5.1 KiB
Python

# Support for HD44780 (20x4 text) LCD displays
#
# Copyright (C) 2018 Kevin O'Connor <kevin@koconnor.net>
# Copyright (C) 2018 Eric Callahan <arksine.code@gmail.com>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging
BACKGROUND_PRIORITY_CLOCK = 0x7fffffff00000000
TextGlyphs = { 'right_arrow': '\x7e' }
HD44780_DELAY = .000040
class HD44780:
def __init__(self, config):
self.printer = config.get_printer()
# pin config
ppins = self.printer.lookup_object('pins')
pins = [ppins.lookup_pin(config.get(name + '_pin'))
for name in ['rs', 'e', 'd4', 'd5', 'd6', 'd7']]
mcu = None
for pin_params in pins:
if mcu is not None and pin_params['chip'] != mcu:
raise ppins.error("hd44780 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.icons = {}
# framebuffers
self.text_framebuffers = [bytearray(' '*40), bytearray(' '*40)]
self.glyph_framebuffer = bytearray(64)
self.all_framebuffers = [
# Text framebuffers
(self.text_framebuffers[0], bytearray('~'*40), 0x80),
(self.text_framebuffers[1], bytearray('~'*40), 0xc0),
# Glyph framebuffer
(self.glyph_framebuffer, bytearray('~'*64), 0x40) ]
def build_config(self):
self.mcu.add_config_cmd(
"config_hd44780 oid=%d rs_pin=%s e_pin=%s"
" d4_pin=%s d5_pin=%s d6_pin=%s d7_pin=%s delay_ticks=%d" % (
self.oid, self.pins[0], self.pins[1],
self.pins[2], self.pins[3], self.pins[4], self.pins[5],
self.mcu.seconds_to_clock(HD44780_DELAY)))
cmd_queue = self.mcu.alloc_command_queue()
self.send_cmds_cmd = self.mcu.lookup_command(
"hd44780_send_cmds oid=%c cmds=%*s", cq=cmd_queue)
self.send_data_cmd = self.mcu.lookup_command(
"hd44780_send_data oid=%c data=%*s", cq=cmd_queue)
def send(self, cmds, is_data=False):
cmd_type = self.send_cmds_cmd
if is_data:
cmd_type = self.send_data_cmd
cmd_type.send([self.oid, cmds], reqclock=BACKGROUND_PRIORITY_CLOCK)
#logging.debug("hd44780 %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 + 4 >= nextpos and nextcount < 16:
diffs[i][1] = nextcount + (nextpos - pos)
del diffs[i+1]
# Transmit changes
for pos, count in diffs:
chip_pos = pos
self.send([fb_id + chip_pos])
self.send(new_data[pos:pos+count], is_data=True)
old_data[:] = new_data
def init(self):
curtime = self.printer.get_reactor().monotonic()
print_time = self.mcu.estimated_print_time(curtime)
# Program 4bit / 2-line mode and then issue 0x02 "Home" command
init = [[0x33], [0x33], [0x33, 0x22, 0x28, 0x02]]
# Reset (set positive direction ; enable display and hide cursor)
init.append([0x06, 0x0c])
for i, cmds in enumerate(init):
minclock = self.mcu.print_time_to_clock(print_time + i * .100)
self.send_cmds_cmd.send([self.oid, cmds], minclock=minclock)
self.flush()
def write_text(self, x, y, data):
if x + len(data) > 20:
data = data[:20 - min(x, 20)]
pos = x + ((y & 0x02) >> 1) * 20
self.text_framebuffers[y & 1][pos:pos+len(data)] = data
def set_glyphs(self, glyphs):
for glyph_name, glyph_data in glyphs.items():
data = glyph_data.get('icon5x8')
if data is not None:
self.icons[glyph_name] = data
def write_glyph(self, x, y, glyph_name):
data = self.icons.get(glyph_name)
if data is not None:
slot, bits = data
self.write_text(x, y, chr(slot))
self.glyph_framebuffer[slot * 8:(slot + 1) * 8] = bits
return 1
char = TextGlyphs.get(glyph_name)
if char is not None:
# Draw character
self.write_text(x, y, char)
return 1
return 0
def write_graphics(self, x, y, pixel_row, pixel_col):
pass
def clear(self):
spaces = ' ' * 40
self.text_framebuffers[0][:] = spaces
self.text_framebuffers[1][:] = spaces
def get_dimensions(self):
return (20, 4)