Updated library

This commit is contained in:
shrkey
2016-04-06 21:08:20 +01:00
parent 1db66c2e48
commit df74fc2eb4
2 changed files with 54 additions and 6 deletions

View File

@@ -50,13 +50,13 @@ class PWM :
self.i2c.write8(self.__MODE2, self.__OUTDRV)
self.i2c.write8(self.__MODE1, self.__ALLCALL)
time.sleep(0.005) # wait for oscillator
mode1 = self.i2c.readU8(self.__MODE1)
mode1 = mode1 & ~self.__SLEEP # wake up (reset sleep)
self.i2c.write8(self.__MODE1, mode1)
time.sleep(0.005) # wait for oscillator
def setPWMFreq(self, freq):
def setPWMFreq(self, freq, correctionFactor=1.0):
"Sets the PWM frequency"
prescaleval = 25000000.0 # 25MHz
prescaleval /= 4096.0 # 12-bit
@@ -65,7 +65,7 @@ class PWM :
if (self.debug):
print "Setting PWM frequency to %d Hz" % freq
print "Estimated pre-scale: %d" % prescaleval
prescale = math.floor(prescaleval + 0.5)
prescale = round(prescaleval * correctionFactor + 0.5)
if (self.debug):
print "Final pre-scale: %d" % prescale
@@ -77,6 +77,57 @@ class PWM :
time.sleep(0.005)
self.i2c.write8(self.__MODE1, oldmode | 0x80)
def setPWMFreqMin(self, freq, correctionFactor=1.0):
"Sets the PWM frequency"
prescaleval = 25000000.0 # 25MHz
prescaleval /= 4096.0 # 12-bit
prescaleval /= float(freq)
prescaleval -= 1.0
if (self.debug):
print "Setting PWM frequency to %d Hz" % freq
print "Estimated pre-scale: %d" % prescaleval
prescale = math.floor(prescaleval * correctionFactor + 0.5)
if (self.debug):
print "Final pre-scale: %d" % prescale
oldmode = self.i2c.readU8(self.__MODE1);
newmode = (oldmode & 0x7F) | 0x10 # sleep
self.i2c.write8(self.__MODE1, newmode) # go to sleep
self.i2c.write8(self.__PRESCALE, int(math.floor(prescale)))
self.i2c.write8(self.__MODE1, oldmode)
time.sleep(0.005)
self.i2c.write8(self.__MODE1, oldmode | 0x80)
def setPWMFreqMax(self, freq, correctionFactor=1.0):
"Sets the PWM frequency"
prescaleval = 25000000.0 # 25MHz
prescaleval /= 4096.0 # 12-bit
prescaleval /= float(freq)
prescaleval -= 1.0
if (self.debug):
print "Setting PWM frequency to %d Hz" % freq
print "Estimated pre-scale: %d" % prescaleval
prescale = math.ceil(prescaleval * correctionFactor + 0.5)
if (self.debug):
print "Final pre-scale: %d" % prescale
oldmode = self.i2c.readU8(self.__MODE1);
newmode = (oldmode & 0x7F) | 0x10 # sleep
self.i2c.write8(self.__MODE1, newmode) # go to sleep
self.i2c.write8(self.__PRESCALE, int(math.floor(prescale)))
self.i2c.write8(self.__MODE1, oldmode)
time.sleep(0.005)
self.i2c.write8(self.__MODE1, oldmode | 0x80)
def getPWMFreq(self):
prescale = self.i2c.readU8(self.__PRESCALE)
calcfreq = 25000000.0 / 4096.0 / ( float(prescale) + 1 )
if (self.debug):
print "Got pre-scale: %d" % prescale
print "Calculated Frequency: %d" % calcfreq
return calcfreq
def setPWM(self, channel, on, off):
"Sets a single PWM channel"
self.i2c.write8(self.__LED0_ON_L+4*channel, on & 0xFF)