hd44780_spi: added lcd support to the mightyboard (#4121)

Signed-off-by: Marc-André Denis <marcadenis@msn.com>

config/generic-mightyboard.cfg

@@ -117,3 +117,16 @@ scl_pin: PJ5
 sda_pin: PJ6
 wiper: 0.50
 scale: 0.773
+
+[display]
+lcd_type: hd44780_spi
+spi_software_mosi_pin: PC3
+spi_software_sclk_pin: PC2
+#miso not used, dummy pin.
+spi_software_miso_pin: PJ1
+latch_pin: PC4
+
+click_pin: ^PJ0
+back_pin: ^PJ2
+up_pin: ^PJ4
+down_pin: ^PJ3

docs/Config_Reference.md

@@ -3089,7 +3089,8 @@ Support for a display attached to the micro-controller.
 [display]
 lcd_type:
 #   The type of LCD chip in use. This may be "hd44780" (which is used
-#   in "RepRapDiscount 2004 Smart Controller" type displays), "st7920"
+#   in "RepRapDiscount 2004 Smart Controller" type displays),"hd44780_spi"
+#   (which is used in mightyboard based printers), "st7920"
 #   (which is used in "RepRapDiscount 12864 Full Graphic Smart
 #   Controller" type displays), "emulated_st7920" (which emulate a ST7920
 #   display but won't work properly with the "st7920" display driver),
@@ -3122,12 +3123,16 @@ lcd_type:
 #spi_software_sclk_pin:
 #spi_software_mosi_pin:
 #spi_software_miso_pin:
-#   The pins connected to an emulated_st7920 type lcd. The en_pin corresponds
+#   The pins connected to an emulated_st7920 or hd44780_spi type lcd.
-#   to the cs_pin of the st7920 type lcd, spi_software_sclk_pin corresponds
+#   The en_pin corresponds to the cs_pin of the st7920 type lcd,
-#   to sclk_pin and spi_software_mosi_pin corresponds to sid_pin. The
+#   spi_software_sclk_pin corresponds to sclk_pin and spi_software_mosi_pin
-#   spi_software_miso_pin needs to be set to an unused pin of the printer
+#   corresponds to sid_pin. The spi_software_miso_pin needs to be set to an
-#   mainboard as the st7920 as no MISO pin but the software spi implementation
+#   unused pin of the printer mainboard as the st7920 as no MISO pin
-#   requires this pin to be configured. The default spi_speed is 1MHz.
+#   but the software spi implementation requires this pin to be configured.
+#   The default spi_speed is 1MHz.
+#latch_pin:
+#   Used with the hd44780_spi type lcd, connected to the latch pin of the
+#   shift register.
 #cs_pin:
 #a0_pin:
 #rst_pin:

klippy/extras/display/display.py

@@ -6,7 +6,7 @@
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import logging, os, ast
-from . import hd44780, st7920, uc1701, menu
+from . import hd44780, hd44780_spi, st7920, uc1701, menu
 
 # Normal time between each screen redraw
 REDRAW_TIME = 0.500
@@ -17,6 +17,7 @@ LCD_chips = {
     'st7920': st7920.ST7920, 'emulated_st7920': st7920.EmulatedST7920,
     'hd44780': hd44780.HD44780, 'uc1701': uc1701.UC1701,
     'ssd1306': uc1701.SSD1306, 'sh1106': uc1701.SH1106,
+    'hd44780_spi': hd44780_spi.hd44780_spi
 }
 
 # Storage of [display_template my_template] config sections

klippy/extras/display/hd44780_spi.py

@@ -0,0 +1,125 @@
+# 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>
+# Copyright (C) 2021  Marc-Andre Denis <marcadenis@msn.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+from .. import bus
+
+LINE_LENGTH_DEFAULT="20"
+LINE_LENGTH_OPTIONS={"16":16, "20":20}
+
+TextGlyphs = { 'right_arrow': '\x7e' }
+
+
+
+class hd44780_spi:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.hd44780_protocol_init = config.getboolean('hd44780_protocol_init',
+            True)
+        # spi config
+        self.spi = bus.MCU_SPI_from_config(
+            config, 0x00, pin_option="latch_pin")
+        self.mcu = self.spi.get_mcu()
+        #self.spi.spi_send([0x01,0xa0])
+        self.data_mask = (1<<1)
+        self.command_mask = 0
+        self.enable_mask = (1<<3)
+
+        self.icons = {}
+        self.line_length = config.getchoice('line_length', LINE_LENGTH_OPTIONS,
+            LINE_LENGTH_DEFAULT)
+
+        # framebuffers
+        self.text_framebuffers = [bytearray(' '*2*self.line_length),
+                                  bytearray(' '*2*self.line_length)]
+        self.glyph_framebuffer = bytearray(64)
+        self.all_framebuffers = [
+            # Text framebuffers
+            (self.text_framebuffers[0], bytearray('~'*2*self.line_length),
+              0x80),
+            (self.text_framebuffers[1], bytearray('~'*2*self.line_length),
+              0xc0),
+            # Glyph framebuffer
+            (self.glyph_framebuffer, bytearray('~'*64), 0x40) ]
+    def send_4_bits(self, cmd, is_data, minclock):
+        if is_data:
+            mask = self.data_mask
+        else:
+            mask = self.command_mask
+        self.spi.spi_send([(cmd & 0xF0) | mask], minclock)
+        self.spi.spi_send([(cmd & 0xF0) | mask | self.enable_mask], minclock)
+        self.spi.spi_send([(cmd & 0xF0) | mask], minclock)
+    def send(self, cmds, is_data=False, minclock=0):
+        for data in cmds:
+            self.send_4_bits(data,is_data,minclock)
+            self.send_4_bits(data<<4,is_data,minclock)
+    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
+        if self.hd44780_protocol_init:
+            init = [[0x33], [0x33], [0x32], [0x28, 0x28, 0x02]]
+        else:
+            init = [[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, minclock=minclock)
+        self.flush()
+    def write_text(self, x, y, data):
+        if x + len(data) > self.line_length:
+            data = data[:self.line_length - min(x, self.line_length)]
+        pos = x + ((y & 0x02) >> 1) * self.line_length
+        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, [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, data):
+        pass
+    def clear(self):
+        spaces = ' ' * 2*self.line_length
+        self.text_framebuffers[0][:] = spaces
+        self.text_framebuffers[1][:] = spaces
+    def get_dimensions(self):
+        return (self.line_length, 4)