X-Git-Url: https://defiant.homedns.org/gitweb/?a=blobdiff_plain;f=bus_pirate.py;h=cdd259fa7581ee42dba23da879fbf10b3aa4d287;hb=2056613e07dc73a25e8426a6ca67fccc88e13fee;hp=f64c8e3cc60a3b24714196df4ee092a7076b0291;hpb=b72bb34f3d40f0e0b6178f261403f93cbda82d95;p=pyshared.git

diff --git a/bus_pirate.py b/bus_pirate.py
index f64c8e3..cdd259f 100644
--- a/bus_pirate.py
+++ b/bus_pirate.py
@@ -64,6 +64,29 @@ class BP:
 		v = struct.unpack(">h", s)
 		return v[0]/1024.0*6.6
 
+	# http://codepad.org/qtYpZmIF
+	def pwm(self, freq, duty_cycle_percent):
+		lPrescaler = {0:1, 1:8 , 2:64, 3:256}
+		Fosc = 32e6
+		Tcy = 2.0 / Fosc
+		period = 1.0 / freq
+		prescaler = 1
+
+		# find needed prescaler
+		for i in range(4):
+			prescaler = lPrescaler[i]
+			PRy = period * 1.0 / (Tcy * prescaler)
+			PRy = int(PRy - 1)
+			OCR = int(PRy * duty_cycle_percent)
+
+			if PRy < (2 ** 16 - 1):
+				break # valid value for PRy, keep values
+
+		cmd = struct.pack(">BBHH", 0b00010010, i, OCR, PRy)
+		ret = self.command(cmd, 1)
+		if ord(ret) != 0x1:
+			raise Exception()
+
 	def spi_command(self, cmd):
 		ret = self.command(cmd, 1)
 		if ord(ret) != 0x1:
@@ -135,7 +158,7 @@ class BP:
 	def i2c_write(self, addr, reg, s):
 		# 1. Write
 		# command (1) | number of write bytes (2) | number of read bytes (2) | bytes to write (0..)
-		msg = struct.pack(">BHHBB%ds" % len(s), 0x08, 2+len(s), 0, addr<<1, reg, s)
+		msg = struct.pack(">BHHBB%ds" % len(s), 0x08, 2+len(s), 0, addr, reg, s)
 		ret = self.command(msg, 1)
 
 		if ord(ret[0]) != 0x1:
@@ -146,7 +169,7 @@ class BP:
 		self.i2c_write(addr, reg, "")
 
 		# command (1) | number of write bytes (2) | number of read bytes (2) | bytes to write (0..)
-		msg = struct.pack(">BHHB", 0x08, 1, num_read, (addr<<1) | 0x1)
+		msg = struct.pack(">BHHB", 0x08, 1, num_read, addr | 0x1)
 		ret = self.command(msg, 1 + num_read)
 
 		if ord(ret[0]) != 0x1:
@@ -156,7 +179,7 @@ class BP:
 
 	def i2c_search(self):
 		for i in range(128):
-			msg = struct.pack(">BHHB", 0x08, 1, 1, i<<1)
+			msg = struct.pack(">BHHB", 0x08, 1, 1, i)
 			ret = self.command(msg, 1)
 			if ord(ret) == 0x1:
 				print "Found I2C Addr: 0x%x" % (i & ~0x1)