X-Git-Url: https://defiant.homedns.org/gitweb/?p=ros_wild_thumper.git;a=blobdiff_plain;f=scripts%2Fi2c.py;fp=scripts%2Fi2c.py;h=2e9a109e0fe2891175726af4e6d739958e032208;hp=0000000000000000000000000000000000000000;hb=3d875e0b7d29c59be6a65b13cd4e2b0d157b6744;hpb=dcdf9baa260c03d34c55339af9950155319c41f0

diff --git a/scripts/i2c.py b/scripts/i2c.py
new file mode 100755
index 0000000..2e9a109
--- /dev/null
+++ b/scripts/i2c.py
@@ -0,0 +1,72 @@
+#!/usr/bin/env python
+# -*- coding: iso-8859-15 -*-
+
+import threading
+import inspect
+import os
+import logging
+from ctypes import *
+from time import sleep
+
+DEBUG=0
+logger = logging.getLogger(__name__)
+
+class i2c:
+	libc = CDLL("libc.so.6")
+	I2C_SLAVE = 0x0703  # Use this slave address
+	__single = None
+	__lock = threading.Lock()
+	__parent_owner = None
+
+	def __init__(self, addr):
+		with i2c.__lock:
+			count = 0
+			while(i2c.__single):
+				parent = inspect.stack()[1][3]
+				count += 1
+				sleep(0.001)
+			if DEBUG:
+				if count > 10:
+					parent_owner = "%s (%d), %s()" % (self.__parent_owner[1], self.__parent_owner[2], self.__parent_owner[3])
+					logger.warning("Error: (%s) I2C blocked %fs by %s!", parent, count*0.001, parent_owner)
+				i2c.__parent_owner = inspect.stack()[1]
+			i2c.__single = True
+		self.dev = i2c.libc.open("/dev/i2c-2", os.O_RDWR)
+		if self.dev < 0:
+			raise IOError("open")
+		err = i2c.libc.ioctl(self.dev, i2c.I2C_SLAVE, addr>>1)
+		if err < 0:
+			raise IOError("ioctl")
+
+	def write(self, s):
+		num_write = i2c.libc.write(self.dev, s, len(s))
+		if num_write != len(s):
+			self.close()
+			raise IOError("write: %d" % (num_write))
+	
+	def read(self, num):
+		buf = create_string_buffer(num)
+		num_read = i2c.libc.read(self.dev, buf, num)
+		if num_read != num:
+			self.close()
+			raise IOError("read: %d" % (num_read))
+		return buf.raw
+
+	def close(self):
+		if self.dev:
+			i2c.libc.close(self.dev)
+			self.dev = None
+			#i2c.__parent_owner = None
+			i2c.__single = None
+
+	def __del__(self):
+		self.close()
+
+if __name__ == "__main__":
+	import struct
+	import sys
+
+	dev = i2c(0x50)
+	s = struct.pack(">Bh", int(sys.argv[1]), int(sys.argv[2]))
+	dev.write(s)
+	dev.close()