add a neopixel driver

gex/PayloadBuilder.py

@@ -21,6 +21,10 @@ class PayloadBuilder:
         """ Add a uint16_t """
         self.buf.extend((num&0xFFFF).to_bytes(length=2, byteorder=self.endian, signed=False))
 
+    def u24(self, num:int):
+        """ Add a uint24_t (for use with RGB colors) """
+        self.buf.extend((num&0xFFFFFF).to_bytes(length=3, byteorder=self.endian, signed=False))
+
     def u32(self, num:int):
         """ Add a uint32_t """
         self.buf.extend((num&0xFFFFFFFF).to_bytes(length=4, byteorder=self.endian, signed=False))

gex/PayloadParser.py

@@ -45,6 +45,11 @@ class PayloadParser:
         slice = self._slice(2)
         return int.from_bytes(slice, byteorder=self.endian, signed=False)
 
+    def u24(self) -> int:
+        """ Read a uint24_t """
+        slice = self._slice(3)
+        return int.from_bytes(slice, byteorder=self.endian, signed=False)
+
     def u32(self) -> int:
         """ Read a uint32_t """
         slice = self._slice(4)

gex/__init__.py

@@ -7,9 +7,9 @@ from gex.Unit import Unit
 from gex.Client import Client
 
 # import all the units
-from gex.units.Pin import Pin
 from gex.units.DOut import DOut
 from gex.units.DIn import DIn
+from gex.units.Neopixel import Neopixel
 
 
 # General, low level

gex/units/Neopixel.py

@@ -0,0 +1,33 @@
+import gex
+
+class Neopixel(gex.Unit):
+    """
+    Raw access to a neopixel strip.
+    """
+
+    def _type(self):
+        return 'NEOPIXEL'
+
+    def get_len(self):
+        """ Get the neopixel strip length """
+        resp = self.query(0x04)
+        pp = gex.PayloadParser(resp)
+        return pp.u16()
+
+    def load(self, colors, reverse=True):
+        """
+        Load colors to the strip.
+
+        The numbers are normally 0xRRGGBB
+        If 'reverse' is false, they're treated as little-endian: 0xBBGGRR.
+        """
+        pb = gex.PayloadBuilder(endian='big' if reverse else 'little')
+        for c in colors:
+            pb.u24(c)
+        self.send(0x01, pb.close())
+
+    def clear(self):
+        """
+        Reset the strip (set all to black)
+        """
+        self.send(0x00)

gex/units/Pin.py

@@ -1,17 +0,0 @@
-import gex
-
-class Pin(gex.Unit):
-    def _type(self):
-        return 'PIN'
-
-    def on_event(self, event:int, payload):
-        pass
-
-    def off(self):
-        self.send(0x00)
-
-    def on(self):
-        self.send(0x01)
-
-    def toggle(self):
-        self.send(0x02)

main.py

@@ -14,13 +14,6 @@ if False:
 
     client.bulk_write(gex.MSG_INI_WRITE, buf)
 
-if False:
-    led = gex.Pin(client, 'LED')
-
-    for i in range(0,10):
-        led.toggle()
-        time.sleep(.1)
-
 if False:
     leds = gex.DOut(client, 'strip')
 
@@ -48,7 +41,7 @@ if False:
         leds.toggle(0xFF)
         time.sleep(.1)
 
-if True:
+if False:
     btn = gex.DIn(client, 'btn')
     strip = gex.DOut(client, 'strip')
 
@@ -56,3 +49,13 @@ if True:
         b = btn.read()
         strip.write((b << 2) | ((~b) & 1))
         time.sleep(.02)
+
+if True:
+    neo = gex.Neopixel(client, 'npx')
+
+    print('We have %d neopixels.\n' % neo.get_len())
+    for i in range(0,512):
+        j = i if i < 256 else 255-(i-256)
+        neo.load([0x660000+j, 0x3300FF-j, 0xFFFF00-(j<<8), 0x0000FF+(j<<8)-j])
+        time.sleep(.005)
+