neopixel: Increase the maximum LED chain length

Rework neopixel updates to use an mcu buffer so that more than 18 LEDs
can be in a chain.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 45 insertions, 12 deletions

diff --git a/klippy/extras/neopixel.py b/klippy/extras/neopixel.py
index 07cad315..307651ea 100644
--- a/klippy/extras/neopixel.py
+++ b/klippy/extras/neopixel.py
@@ -1,14 +1,17 @@
 # Support for "neopixel" leds
 #
-# Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2019-2020  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
 
 BACKGROUND_PRIORITY_CLOCK = 0x7fffffff00000000
 
 BIT_MAX_TIME=.000004
 RESET_MIN_TIME=.000050
 
+MAX_MCU_SIZE = 500  # Sanity check on LED chain length
+
 class PrinterNeoPixel:
     def __init__(self, config):
         self.printer = config.get_printer()
@@ -21,27 +24,33 @@ class PrinterNeoPixel:
         self.pin = pin_params['pin']
         self.mcu.register_config_callback(self.build_config)
         self.color_order_GRB = config.getboolean("color_order_GRB", True)
-        self.chain_count = config.getint('chain_count', 1, minval=1, maxval=18)
-        self.neopixel_send_cmd = None
+        self.chain_count = config.getint('chain_count', 1,
+                                         minval=1, maxval=MAX_MCU_SIZE//3)
+        self.neopixel_update_cmd = self.neopixel_send_cmd = None
         # Initial color
+        self.color_data = bytearray(self.chain_count * 3)
         red = config.getfloat('initial_RED', 0., minval=0., maxval=1.)
         green = config.getfloat('initial_GREEN', 0., minval=0., maxval=1.)
         blue = config.getfloat('initial_BLUE', 0., minval=0., maxval=1.)
         self.update_color_data(red, green, blue)
-        self.printer.register_event_handler("klippy:connect", self.send_data)
+        self.old_color_data = bytearray([d ^ 1 for d in self.color_data])
         # Register commands
+        self.printer.register_event_handler("klippy:connect", self.send_data)
         gcode = self.printer.lookup_object('gcode')
         gcode.register_mux_command("SET_LED", "LED", name, self.cmd_SET_LED,
                                    desc=self.cmd_SET_LED_help)
     def build_config(self):
         bmt = self.mcu.seconds_to_clock(BIT_MAX_TIME)
         rmt = self.mcu.seconds_to_clock(RESET_MIN_TIME)
-        self.mcu.add_config_cmd("config_neopixel oid=%d pin=%s"
+        self.mcu.add_config_cmd("config_neopixel oid=%d pin=%s data_size=%d"
                                 " bit_max_ticks=%d reset_min_ticks=%d"
-                                % (self.oid, self.pin, bmt, rmt))
+                                % (self.oid, self.pin, self.chain_count * 3,
+                                   bmt, rmt))
         cmd_queue = self.mcu.alloc_command_queue()
-        self.neopixel_send_cmd = self.mcu.lookup_command(
-            "neopixel_send oid=%c data=%*s", cq=cmd_queue)
+        self.neopixel_update_cmd = self.mcu.lookup_command(
+            "neopixel_update oid=%c pos=%hu data=%*s", cq=cmd_queue)
+        self.neopixel_send_cmd = self.mcu.lookup_query_command(
+            "neopixel_send oid=%c", "neopixel_result success=%c", cq=cmd_queue)
     def update_color_data(self, red, green, blue, index=None):
         red = int(red * 255. + .5)
         blue = int(blue * 255. + .5)
@@ -51,13 +60,37 @@ class PrinterNeoPixel:
         else:
             color_data = [red, green, blue]
         if index is None:
-            self.color_data = color_data * self.chain_count
+            self.color_data[:] = color_data * self.chain_count
         else:
             self.color_data[(index-1)*3:index*3] = color_data
     def send_data(self, minclock=0):
-        self.neopixel_send_cmd.send([self.oid, self.color_data],
-                                    minclock=minclock,
-                                    reqclock=BACKGROUND_PRIORITY_CLOCK)
+        old_data, new_data = self.old_color_data, self.color_data
+        if new_data == old_data:
+            return
+        # 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
+        ucmd = self.neopixel_update_cmd.send
+        for pos, count in diffs:
+            ucmd([self.oid, pos, new_data[pos:pos+count]],
+                 reqclock=BACKGROUND_PRIORITY_CLOCK)
+        old_data[:] = new_data
+        # Instruct mcu to update the LEDs
+        scmd = self.neopixel_send_cmd.send
+        for i in range(8):
+            params = scmd([self.oid], minclock=minclock)
+            if params['success']:
+                break
+        else:
+            logging.info("Neopixel update did not succeed")
     cmd_SET_LED_help = "Set the color of an LED"
     def cmd_SET_LED(self, gcmd):
         # Parse parameters