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 load(overlay, auto_unload=True):
""" Attempt to load an overlay with the given name. If auto_unload=True it
will be auto-unloaded at program exit (the current cape manager crashes
when trying to unload certain overlay fragments). """
if isLoaded(overlay): return
with open(SLOTS_FILE, 'wb') as f:
f.write(overlay)
if auto_unload:
addToCleanup(lambda: unload(overlay))
def load(overlay, auto_unload=True):
""" Attempt to load an overlay with the given name. If auto_unload=True it
will be auto-unloaded at program exit (the current cape manager crashes
when trying to unload certain overlay fragments). """
if isLoaded(overlay): return
with open(SLOTS_FILE, 'wb') as f:
f.write(overlay)
if auto_unload:
addToCleanup(lambda: unload(overlay))
def export(gpio_pin, unexport_on_exit=False):
""" Reserves a pin for userspace use with sysfs /sys/class/gpio interface.
If unexport_on_exit=True unexport(gpio_pin) will be called automatically
when the program exits. Returns True if pin was exported, False if it was
already under userspace control. """
if ("USR" in gpio_pin):
# The user LEDs are already under userspace control
return True
gpio_num = GPIO[gpio_pin]['gpio_num']
gpio_file = '%s/gpio%i' % (GPIO_FILE_BASE, gpio_num)
if (os.path.exists(gpio_file)):
# Pin already under userspace control
return True
with open(EXPORT_FILE, 'wb') as f:
f.write(str(gpio_num))
if unexport_on_exit:
addToCleanup(lambda: unexport(gpio_pin))
return True
def __init__(self, eqep_num):
'''
RotaryEncoder(eqep_num)
Creates an instance of the class RotaryEncoder.
eqep_num determines which eQEP pins are set up.
eqep_num can be: EQEP0, EQEP1, EQEP2 or EQEP2b based on which pins \
the rotary encoder is connected to.
'''
assert 0 <= eqep_num <= 3, "eqep_num must be between 0 and 3"
if eqep_num == 3:
overlay = "PyBBIO-eqep2b"
eqep_num = 2
else:
overlay = 'PyBBIO-eqep%i' % eqep_num
pwmss_overlay = "PyBBIO-epwmss%i" % eqep_num
cape_manager.load(pwmss_overlay, auto_unload=False)
delay(10)
cape_manager.load(overlay, auto_unload=False)
delay(250) # Give driver time to load
self.base_dir = self._eqep_dirs[eqep_num]
self.enable()
addToCleanup(self.disable)
def __init__(self, eqep_num):
'''
RotaryEncoder(eqep_num)
Creates an instance of the class RotaryEncoder.
eqep_num determines which eQEP pins are set up.
eqep_num can be: EQEP0, EQEP1, EQEP2 or EQEP2b based on which pins \
the rotary encoder is connected to.
'''
assert 0 <= eqep_num <= 3 , "eqep_num must be between 0 and 3"
if eqep_num == 3:
overlay = "PyBBIO-eqep2b"
eqep_num = 2
else:
overlay = 'PyBBIO-eqep%i' % eqep_num
pwmss_overlay = "PyBBIO-epwmss%i" % eqep_num
cape_manager.load(pwmss_overlay, auto_unload=False)
delay(10)
cape_manager.load(overlay, auto_unload=False)
delay(250) # Give driver time to load
self.base_dir = self._eqep_dirs[eqep_num]
self.enable()
addToCleanup(self.disable)