Create separate BCM2711 structure.

[Adafruit_Blinka-hackapet.git] / src / adafruit_blinka / microcontroller / bcm2711 / neopixel.py

diff --git a/src/adafruit_blinka/microcontroller/bcm2711/neopixel.py b/src/adafruit_blinka/microcontroller/bcm2711/neopixel.py
new file mode 100644 (file)
index 0000000..6235f3c
--- /dev/null
+++ b/src/adafruit_blinka/microcontroller/bcm2711/neopixel.py
@@ -0,0 +1,123 @@
+"""BCM2711 NeoPixel Driver Class"""
+import time
+import atexit
+import _rpi_ws281x as ws
+
+# LED configuration.
+# pylint: disable=redefined-outer-name,too-many-branches,too-many-statements
+# pylint: disable=global-statement,protected-access
+LED_CHANNEL = 0
+LED_FREQ_HZ = 800000  # Frequency of the LED signal.  We only support 800KHz
+LED_DMA_NUM = 10  # DMA channel to use, can be 0-14.
+LED_BRIGHTNESS = 255  # We manage the brightness in the neopixel library
+LED_INVERT = 0  # We don't support inverted logic
+LED_STRIP = None  # We manage the color order within the neopixel library
+
+# a 'static' object that we will use to manage our PWM DMA channel
+# we only support one LED strip per raspi
+_led_strip = None
+_buf = None
+
+
+def neopixel_write(gpio, buf):
+    """NeoPixel Writing Function"""
+    global _led_strip  # we'll have one strip we init if its not at first
+    global _buf  # we save a reference to the buf, and if it changes we will cleanup and re-init.
+
+    if _led_strip is None or buf is not _buf:
+        # This is safe to call since it doesn't do anything if _led_strip is None
+        neopixel_cleanup()
+
+        # Create a ws2811_t structure from the LED configuration.
+        # Note that this structure will be created on the heap so you
+        # need to be careful that you delete its memory by calling
+        # delete_ws2811_t when it's not needed.
+        _led_strip = ws.new_ws2811_t()
+        _buf = buf
+
+        # Initialize all channels to off
+        for channum in range(2):
+            channel = ws.ws2811_channel_get(_led_strip, channum)
+            ws.ws2811_channel_t_count_set(channel, 0)
+            ws.ws2811_channel_t_gpionum_set(channel, 0)
+            ws.ws2811_channel_t_invert_set(channel, 0)
+            ws.ws2811_channel_t_brightness_set(channel, 0)
+
+        channel = ws.ws2811_channel_get(_led_strip, LED_CHANNEL)
+
+        # Initialize the channel in use
+        count = 0
+        if len(buf) % 3 == 0:
+            # most common, divisible by 3 is likely RGB
+            LED_STRIP = ws.WS2811_STRIP_RGB
+            count = len(buf) // 3
+        elif len(buf) % 4 == 0:
+            LED_STRIP = ws.SK6812_STRIP_RGBW
+            count = len(buf) // 4
+        else:
+            raise RuntimeError("We only support 3 or 4 bytes-per-pixel")
+
+        ws.ws2811_channel_t_count_set(
+            channel, count
+        )  # we manage 4 vs 3 bytes in the library
+        ws.ws2811_channel_t_gpionum_set(channel, gpio._pin.id)
+        ws.ws2811_channel_t_invert_set(channel, LED_INVERT)
+        ws.ws2811_channel_t_brightness_set(channel, LED_BRIGHTNESS)
+        ws.ws2811_channel_t_strip_type_set(channel, LED_STRIP)
+
+        # Initialize the controller
+        ws.ws2811_t_freq_set(_led_strip, LED_FREQ_HZ)
+        ws.ws2811_t_dmanum_set(_led_strip, LED_DMA_NUM)
+
+        resp = ws.ws2811_init(_led_strip)
+        if resp != ws.WS2811_SUCCESS:
+            if resp == -5:
+                raise RuntimeError(
+                    "NeoPixel support requires running with sudo, please try again!"
+                )
+            message = ws.ws2811_get_return_t_str(resp)
+            raise RuntimeError(
+                "ws2811_init failed with code {0} ({1})".format(resp, message)
+            )
+        atexit.register(neopixel_cleanup)
+
+    channel = ws.ws2811_channel_get(_led_strip, LED_CHANNEL)
+    if gpio._pin.id != ws.ws2811_channel_t_gpionum_get(channel):
+        raise RuntimeError("Raspberry Pi neopixel support is for one strip only!")
+
+    if ws.ws2811_channel_t_strip_type_get(channel) == ws.WS2811_STRIP_RGB:
+        bpp = 3
+    else:
+        bpp = 4
+    # assign all colors!
+    for i in range(len(buf) // bpp):
+        r = buf[bpp * i]
+        g = buf[bpp * i + 1]
+        b = buf[bpp * i + 2]
+        if bpp == 3:
+            pixel = (r << 16) | (g << 8) | b
+        else:
+            w = buf[bpp * i + 3]
+            pixel = (w << 24) | (r << 16) | (g << 8) | b
+        ws.ws2811_led_set(channel, i, pixel)
+
+    resp = ws.ws2811_render(_led_strip)
+    if resp != ws.WS2811_SUCCESS:
+        message = ws.ws2811_get_return_t_str(resp)
+        raise RuntimeError(
+            "ws2811_render failed with code {0} ({1})".format(resp, message)
+        )
+    time.sleep(0.001 * ((len(buf) // 100) + 1))  # about 1ms per 100 bytes
+
+
+def neopixel_cleanup():
+    """Cleanup when we're done"""
+    global _led_strip
+
+    if _led_strip is not None:
+        # Ensure ws2811_fini is called before the program quits.
+        ws.ws2811_fini(_led_strip)
+        # Example of calling delete function to clean up structure memory.  Isn't
+        # strictly necessary at the end of the program execution here, but is good practice.
+        ws.delete_ws2811_t(_led_strip)
+        _led_strip = None