Prior to merge.

[micorpython_ir.git] / ir_tx / nec.py

diff --git a/ir_tx/nec.py b/ir_tx/nec.py
new file mode 100644 (file)
index 0000000..8cf39e7
--- /dev/null
+++ b/ir_tx/nec.py
@@ -0,0 +1,38 @@
+# nec.py Encoder for IR remote control using synchronous code
+# NEC protocol.
+
+# Author: Peter Hinch
+# Copyright Peter Hinch 2020 Released under the MIT license
+
+from micropython import const
+from ir_tx import IR, STOP
+
+_TBURST = const(563)
+_T_ONE = const(1687)
+
+class NEC(IR):
+
+    def __init__(self, pin, freq=38000, verbose=False):  # NEC specifies 38KHz
+        super().__init__(pin, freq, 68, 50, verbose)
+
+    def _bit(self, b):
+        self.append(_TBURST, _T_ONE if b else _TBURST)
+
+    def tx(self, addr, data, _):  # Ignore toggle
+        self.append(9000, 4500)
+        if addr < 256:  # Short address: append complement
+            addr |= ((addr ^ 0xff) << 8)
+        for _ in range(16):
+            self._bit(addr & 1)
+            addr >>= 1
+        data |= ((data ^ 0xff) << 8)
+        for _ in range(16):
+            self._bit(data & 1)
+            data >>= 1
+        self.append(_TBURST)
+
+    def repeat(self):
+        self.aptr = 0
+        self.append(9000, 2250, _TBURST, STOP)
+        self.aptr = 0  # Reset pointer
+        self.cb(self._tim)  # Initiate physical transmission.