From 5e8ea81e656170f78ed9c126ad857955d81cc414 Mon Sep 17 00:00:00 2001
From: Erik Andresen <erik@vontaene.de>
Date: Fri, 21 Jul 2017 20:29:03 +0200
Subject: [PATCH] Added jump to bootloader Added pwm to bus_pirate

---
 bootloader.py |  5 ++++-
 bus_pirate.py | 23 +++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/bootloader.py b/bootloader.py
index 04370cd..1f5707a 100755
--- a/bootloader.py
+++ b/bootloader.py
@@ -179,9 +179,12 @@ if __name__ == "__main__":
 	usage = "usage: %prog [options] addr [ihex]"
 	parser = OptionParser(usage=usage)
 	parser.add_option("-b", "--start-bootloader", action="store_true", dest="bToBoot", default=False, help="Start Bootloader")
+	parser.add_option("-j", "--jump", action="store_true", dest="bJump", default=False, help="Jump to Program")
 
 	(options, args) = parser.parse_args()
-	if len(args) > 0:
+	if not args:
+		print "Missing Address"
+	else:
 		addr = int(args[0], 16)
 		if options.bToBoot:
 			to_bootloader(addr)
diff --git a/bus_pirate.py b/bus_pirate.py
index 4ef9c61..52a1c5c 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):
+		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)
+
+			if PRy < (2 ** 16 - 1):
+				break # valid value for PRy, keep values
+
+		cmd = struct.pack(">BBHH", 0b00010010, prescaler, duty_cycle, period)
+		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:
-- 
2.39.5