def pwmDisable(pwm_pin):
""" Disables PWM output on given pin. """
pin_config = PWM_PINS[pwm_pin]
assert (pin_config), "*Invalid PWM pin: '%s'" % pwm_pin
helper_path = pin_config[1]
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN), '0')
PWM_PINS_ENABLED[pwm_pin] = False
def analogWrite(pwm_pin, value, resolution=RES_8BIT, polarity=0):
""" Sets the duty cycle of the given PWM output using the
given resolution. If polarity=0 this will set the width of
the positive pulse, otherwise it will set the width of the
negative pulse. """
# Make sure the pin is configured:
pwmEnable(pwm_pin)
pin_config = PWM_PINS[pwm_pin]
helper_path = pin_config[1]
try:
assert resolution > 0, "*PWM resolution must be greater than 0"
if (value < 0): value = 0
if (value >= resolution): value = resolution-1
period_ns = int(sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD)))
# Todo: round values properly!:
duty_ns = int(value * (period_ns/resolution))
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), str(duty_ns))
if polarity == 0:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_POLARITY), '0')
else:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_POLARITY), '1')
# Enable output:
if (sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN)) == '0\n'):
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN), '1')
except IOError:
print "*PWM pin '%s' reserved by another process!" % pwm_pin
def analogWrite(pwm_pin, value, resolution=RES_8BIT, polarity=0):
""" Sets the duty cycle of the given PWM output using the
given resolution. If polarity=0 this will set the width of
the positive pulse, otherwise it will set the width of the
negative pulse. """
# Make sure the pin is configured:
pwmEnable(pwm_pin)
pin_config = PWM_PINS[pwm_pin]
helper_path = pin_config[1]
try:
assert resolution > 0, "*PWM resolution must be greater than 0"
if (value < 0): value = 0
if (value >= resolution): value = resolution-1
period_ns = int(sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD)))
# Todo: round values properly!:
duty_ns = int(value * (period_ns/resolution))
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), str(duty_ns))
if polarity == 0:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_POLARITY), '0')
else:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_POLARITY), '1')
# Enable output:
if (sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN)) == '0\n'):
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN), '1')
except IOError:
print "*PWM pin '%s' reserved by another process!" % pwm_pin
def pwmDisable(pwm_pin):
""" Disables PWM output on given pin. """
pin_config = PWM_PINS[pwm_pin]
assert (pin_config), "*Invalid PWM pin: '%s'" % pwm_pin
helper_path = pin_config[1]
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN), '0')
PWM_PINS_ENABLED[pwm_pin] = False
def pwmFrequency(pwm_pin, freq_hz):
""" Sets the frequncy in Hertz of the given PWM output's module. """
assert (pwm_pin in PWM_PINS), "*Invalid PWM pin: '%s'" % pwm_pin
assert freq_hz > 0, "*PWM frequency must be greater than 0"
# Make sure the pin is configured:
pwmEnable(pwm_pin)
# calculate the duty cycle in nanoseconds for the new period:
pin_config = PWM_PINS[pwm_pin]
helper_path = pin_config[1]
old_duty_ns = int(sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY)))
old_period_ns = int(sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD)))
duty_percent = old_duty_ns / old_period_ns
new_period_ns = int(1e9/freq_hz)
# Todo: round values properly!:
new_duty_ns = int(duty_percent * new_period_ns)
try:
# Duty cyle must be set to 0 before changing frequency:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), '0')
# Set new frequency:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD), str(new_period_ns))
# Set the duty cycle:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), str(new_duty_ns))
except IOError:
print "*PWM pin '%s' reserved by another process!" % pwm_pin
def pwmFrequency(pwm_pin, freq_hz):
""" Sets the frequncy in Hertz of the given PWM output's module. """
assert (pwm_pin in PWM_PINS), "*Invalid PWM pin: '%s'" % pwm_pin
assert freq_hz > 0, "*PWM frequency must be greater than 0"
# Make sure the pin is configured:
pwmEnable(pwm_pin)
# calculate the duty cycle in nanoseconds for the new period:
pin_config = PWM_PINS[pwm_pin]
helper_path = pin_config[1]
old_duty_ns = int(sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY)))
old_period_ns = int(sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD)))
duty_percent = old_duty_ns / old_period_ns
new_period_ns = int(1e9/freq_hz)
# Todo: round values properly!:
new_duty_ns = int(duty_percent * new_period_ns)
try:
# Duty cyle must be set to 0 before changing frequency:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), '0')
# Set new frequency:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD), str(new_period_ns))
# Set the duty cycle:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), str(new_duty_ns))
except IOError:
print "*PWM pin '%s' reserved by another process!" % pwm_pin
def setFrequency(self, freq):
'''
setFrequency(freq)
Set the frequency in Hz at which the driver reports new positions.
'''
period_file = "%s/period" % self.base_dir
return sysfs.kernelFileIO(period_file, str(1000000000 / freq))
def setPosition(self, val):
'''
setPosition(value)
Give a new value to the current position
'''
position_file = "%s/position" % self.base_dir
return sysfs.kernelFileIO(position_file, str(val))
def disable(self):
'''
disable()
Turns the eQEP hardware OFF
'''
enable_file = "%s/enabled" % self.base_dir
return sysfs.kernelFileIO(enable_file, '0')
def getMode(self): ''' getMode() Returns the mode the eQEP hardware is in. ''' mode_file = "%s/mode" % self.base_dir return sysfs.kernelFileIO(mode_file)
def getMode(self):
'''
getMode()
Returns the mode the eQEP hardware is in.
'''
mode_file = "%s/mode" % self.base_dir
return sysfs.kernelFileIO(mode_file)
def disable(self): ''' disable() Turns the eQEP hardware OFF ''' enable_file = "%s/enabled" % self.base_dir return sysfs.kernelFileIO(enable_file, 0)
def setPosition(self,val): ''' setPosition(value) Give a new value to the current position ''' position_file = "%s/position" % self.base_dir return sysfs.kernelFileIO(position_file,val)
def setFrequency(self,freq): ''' setFrequency(freq) Set the frequency in Hz at which the driver reports new positions. ''' period_file = "%s/period" % self.base_dir return sysfs.kernelFileIO(period_file,1000000000/freq)
def setRelative(self): ''' setRelative() Set mode as Relative The position is reset when the unit timer overflows. ''' mode_file = "%s/mode" % self.base_dir return sysfs.kernelFileIO(mode_file, 1)
def init_encoder(self):
enc = sysfs.kernelFileIO(self.encoder_file).split()
d = int(enc[0]) * self.coef_d
g = int(enc[1]) * self.coef_g * 1.5
angle = (d - g) * self.teta_to_radian
with self.lock:
self.previous = (d, g)
self.A = angle
def setRelative(self):
'''
setRelative()
Set mode as Relative
The position is reset when the unit timer overflows.
'''
mode_file = "%s/mode" % self.base_dir
return sysfs.kernelFileIO(mode_file, '1')
def init_encoder(self):
enc = sysfs.kernelFileIO(self.encoder_file).split()
d = int(enc[0]) * self.coef_d
g = int(enc[1]) * self.coef_g * 1.5
angle = (d - g) * self.teta_to_radian
with self.lock:
self.previous = (d, g)
self.A = angle
def pwmEnable(pwm_pin):
""" Ensures PWM module for the given pin is enabled and its ocp helper
is loaded. """
global PWM_PINS_ENABLED
if PWM_PINS_ENABLED.get(pwm_pin): return
pin_config = PWM_PINS[pwm_pin]
assert (pin_config), "*Invalid PWM pin: '%s'" % pwm_pin
for overlay in pin_config[2]:
cape_manager.load(overlay, auto_unload=False)
delay(250) # Give it some time to take effect
cape_manager.load(pin_config[0], auto_unload=False)
delay(250)
helper_path = pin_config[1]
# Make sure output is disabled, so it won't start outputing a
# signal until analogWrite() is called:
if (sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN)) == '1\n'):
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN), '0')
# Duty cyle must be set to 0 before changing frequency:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), '0')
# Is this still true??
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD),
str(PWM_DEFAULT_PERIOD))
addToCleanup(lambda : pwmDisable(pwm_pin))
PWM_PINS_ENABLED[pwm_pin] = True
def pwmEnable(pwm_pin):
""" Ensures PWM module for the given pin is enabled and its ocp helper
is loaded. """
global PWM_PINS_ENABLED
if PWM_PINS_ENABLED.get(pwm_pin): return
pin_config = PWM_PINS[pwm_pin]
assert (pin_config), "*Invalid PWM pin: '%s'" % pwm_pin
for overlay in pin_config[2]:
cape_manager.load(overlay, auto_unload=False)
delay(250) # Give it some time to take effect
cape_manager.load(pin_config[0], auto_unload=False)
delay(250)
helper_path = pin_config[1]
# Make sure output is disabled, so it won't start outputing a
# signal until analogWrite() is called:
if (sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN)) == '1\n'):
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_RUN), '0')
# Duty cyle must be set to 0 before changing frequency:
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_DUTY), '0')
# Is this still true??
sysfs.kernelFileIO('%s/%s' % (helper_path, PWM_PERIOD),
str(PWM_DEFAULT_PERIOD))
addToCleanup(lambda : pwmDisable(pwm_pin))
PWM_PINS_ENABLED[pwm_pin] = True
def setAbsolute(self): ''' setAbsolute() Set mode as Absolute The position starts at zero and is incremented or decremented by the encoder's movement ''' mode_file = "%s/mode" % self.base_dir return sysfs.kernelFileIO(mode_file, 0)
def setAbsolute(self):
'''
setAbsolute()
Set mode as Absolute
The position starts at zero and is incremented or
decremented by the encoder's movement
'''
mode_file = "%s/mode" % self.base_dir
return sysfs.kernelFileIO(mode_file, '0')
def _get_encoder(self):
enc = sysfs.kernelFileIO(self.encoder_file).split()
d = int(enc[0]) * self.coef_d
g = int(enc[1]) * self.coef_g * 1.5
angle = (d - g)
ret = d - self.previous[0], g - self.previous[1], angle
with self.lock:
self.previous = (d, g)
return ret
def _get_encoder(self):
enc = sysfs.kernelFileIO(self.encoder_file).split()
d = int(enc[0]) * self.coef_d
g = int(enc[1]) * self.coef_g * 1.5
angle = (d - g)
ret = d - self.previous[0], g - self.previous[1], angle
with self.lock:
self.previous = (d, g)
return ret
def getPosition(self):
'''
getPosition()
Get the current position of the encoder.
In absolute mode, this attribute represents the current position
of the encoder.
In relative mode, this attribute represents the position of the
encoder at the last unit timer overflow.
'''
position_file = "%s/position" % self.base_dir
return sysfs.kernelFileIO(position_file)
def getPosition(self): ''' getPosition() Get the current position of the encoder. In absolute mode, this attribute represents the current position of the encoder. In relative mode, this attribute represents the position of the encoder at the last unit timer overflow. ''' position_file = "%s/position" % self.base_dir return sysfs.kernelFileIO(position_file)
