From cd0fc8c53f8f2d61375da310b924825f0bddc549 Mon Sep 17 00:00:00 2001
From: Uwe Hermann <uwe@hermann-uwe.de>
Date: Tue, 27 Apr 2010 23:13:45 +0200
Subject: [PATCH] Add Python decoder for the Wii Nunchuk.

Untested, unfinished.
---
 scripts/Makefile.am |   2 +-
 scripts/nunchuk.py  | 157 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 158 insertions(+), 1 deletion(-)
 create mode 100644 scripts/nunchuk.py

diff --git a/scripts/Makefile.am b/scripts/Makefile.am
index 2372ff2..ae4a3c8 100644
--- a/scripts/Makefile.am
+++ b/scripts/Makefile.am
@@ -18,5 +18,5 @@
 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 ##
 
-dist_pkgdata_SCRIPTS = i2c.py transitioncounter.py
+dist_pkgdata_SCRIPTS = i2c.py nunchuk.py transitioncounter.py
 
diff --git a/scripts/nunchuk.py b/scripts/nunchuk.py
new file mode 100644
index 0000000..409e120
--- /dev/null
+++ b/scripts/nunchuk.py
@@ -0,0 +1,157 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, write to the Free Software
+## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+##
+
+#
+# Nintendo Wii Nunchuk decoder
+#
+
+# TODO: Description
+
+# FIXME: This is just some example input for testing purposes...
+example_packets = [
+	# START condition.
+	{'type': 'S',  'range': (10, 11), 'data': None, 'ann': ''},
+
+	# Nunchuk init: Write 0x40,0x00 to slave address 0x54.
+	{'type': 'AW', 'range': (12, 13), 'data': 0x54, 'ann': ''},
+	{'type': 'DW', 'range': (14, 15), 'data': 0x40, 'ann': ''},
+	{'type': 'AW', 'range': (16, 17), 'data': 0x54, 'ann': ''},
+	{'type': 'DW', 'range': (18, 19), 'data': 0x00, 'ann': ''},
+
+	# Get data: Read 6 bytes of data.
+	{'type': 'DR', 'range': (20, 21), 'data': 0x11, 'ann': ''},
+	{'type': 'DR', 'range': (22, 23), 'data': 0x22, 'ann': ''},
+	{'type': 'DR', 'range': (24, 25), 'data': 0x33, 'ann': ''},
+	{'type': 'DR', 'range': (26, 27), 'data': 0x44, 'ann': ''},
+	{'type': 'DR', 'range': (28, 29), 'data': 0x55, 'ann': ''},
+	{'type': 'DR', 'range': (30, 31), 'data': 0x66, 'ann': ''},
+
+	# STOP condition.
+	{'type': 'P',  'range': (32, 33), 'data': None, 'ann': ''},
+]
+
+def decode(inbuf):
+	"""Nintendo Wii Nunchuk decoder"""
+
+	# FIXME: Get the data in the correct format in the first place.
+	inbuf = [ord(x) for x in inbuf]
+	out = []
+	o = {}
+
+	# TODO: Pass in metadata.
+
+	# States
+	IDLE, START, NUNCHUK_SLAVE, INIT, INITIALIZED = range(5)
+	state = IDLE # TODO: Can we assume a certain initial state?
+
+	sx = sy = ax = ay = az = bz = bc = 0
+
+	databytecount = 0
+
+	# Loop over all I2C packets.
+	for p in example_packets:
+		if p['type'] == 'S': # TODO: Handle 'Sr' here, too?
+			state = START
+
+		elif p['type'] == 'Sr':
+			pass # FIXME
+
+		elif p['type'] == 'AR':
+			# TODO: Error/Warning, not supported, I think.
+			pass
+
+		elif p['type'] == 'AW':
+			# The Wii Nunchuk always has slave address 0x54.
+			# TODO: Handle this stuff more correctly.
+			if p['data'] == 0x54:
+				pass # TODO
+			else:
+				pass # TODO: What to do here? Ignore? Error?
+
+		elif p['type'] == 'DR' and state == INITIALIZED:
+			if databytecount == 0:
+				sx = p['data']
+			elif databytecount == 1:
+				sy = p['data']
+			elif databytecount == 2:
+				ax = p['data'] << 2
+			elif databytecount == 3:
+				ay = p['data'] << 2
+			elif databytecount == 4:
+				az = p['data'] << 2
+			elif databytecount == 5:
+				bz =  (p['data'] & (1 << 0)) >> 0
+				bc =  (p['data'] & (1 << 1)) >> 1
+				ax |= (p['data'] & (3 << 2)) >> 2
+				ay |= (p['data'] & (3 << 4)) >> 4
+				az |= (p['data'] & (3 << 6)) >> 6
+				# del o
+				o = {'type': 'D', 'range': (0, 0), 'data': []}
+			 	o['data'] = [sx, sy, ax, ay, az, bz, bc]
+				# sx = sy = ax = ay = az = bz = bc = 0
+			else:
+				pass # TODO
+
+			if 0 <= databytecount <= 5:
+				databytecount += 1
+
+			# TODO: If 6 bytes read -> save and reset
+
+		# TODO
+		elif p['type'] == 'DR' and state != INITIALIZED:
+			pass
+
+		elif p['type'] == 'DW':
+			if p['data'] == 0x40 and state == START:
+				state = INIT
+			elif p['data'] == 0x00 and state == INIT:
+				o = {'type': 'I', 'range': (0, 0), 'data': []}
+				o['data'] = [0x40, 0x00]
+				out.append(o)
+				state = INITIALIZED
+			else:
+				pass # TODO
+
+		elif p['type'] == 'P':
+			out.append(o)
+			state = INITIALIZED
+			databytecount = 0
+
+	print out
+
+	# FIXME
+	return ''
+
+def register():
+	return {
+		'id': 'nunchuk',
+		'name': 'Nunchuk',
+		'desc': 'Nintendo Wii Nunchuk decoder',
+		'inputformats': ['i2c'],
+		'ouputformats': ['nunchuk'],
+	}
+
+# Use psyco (if available) as it results in huge performance improvements.
+try:
+	import psyco
+	psyco.bind(decode)
+except ImportError:
+	pass
+
-- 
2.30.2