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Fix of pwm.py to work with the new sysfs on V3b #9

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Merged
YaoQ merged 4 commits into from
Jan 10, 2017
Merged

Fix of pwm.py to work with the new sysfs on V3b #9

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7c6b045
Fixed pwm on pcduino v3b
JohannesAck Dec 24, 2016
45c35d2
Fixed a bug in previoius commit, that makes the duty cycle become 0 i…
JohannesAck Dec 24, 2016
e18ec80
Fixed pwm on V3B
JohannesAck Jan 10, 2017
1f7b1a5
Fixed gpio.py for new sysfs-pwm
JohannesAck Jan 10, 2017
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9 changes: 9 additions & 0 deletions pcduino/gpio.py
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
from pinmap import PinMap
import os.path


__all__ = ['HIGH', 'LOW', 'INPUT', 'OUTPUT','digital_write', 'digital_read',
Expand Down Expand Up @@ -35,6 +36,14 @@ def digital_read(channel):

def pin_mode(channel, mode):
""" Set Mode of a GPIO channel """

# has to disable new sysfs pwm
pwmPath = '/sys/class/misc/pwmtimer/enable/'
ending = 'pwm' + str(channel)
if os.path.isfile(os.path.join(pwmPath ,ending)):
with open(os.path.join(pwmPath, ending), 'w+') as f:
f.write('0')

path = gpio_mode_pins.get_path(channel)
with open(path, 'w+') as f:
f.write('0' if mode == INPUT else '1')
30 changes: 21 additions & 9 deletions pcduino/pwm.py
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Original file line number Diff line number Diff line change
@@ -1,9 +1,5 @@
import os.path

from pinmap import PinMap


pins = PinMap('/sys/class/leds', 'pwm', 5)
from os import listdir

MAX_PWM_LEVEL = 255

Expand All @@ -13,14 +9,30 @@ def analog_write(pin, value):
value can be an number between 0 and 255.

"""
path = pins.get_path(pin)

with open(os.path.join(path, 'max_brightness')) as f:
path = '/sys/class/misc/pwmtimer/'

ending = 'pwm' + str(pin)

pins = listdir(os.path.join(path, 'enable'))
if not ending in pins:
raise ValueError("Pin not found, PWM only possible on " + " ".join(str(p) for p in pins) + ".")

with open(os.path.join(path, 'max_level',ending)) as f:
max_value = int(f.read())

if value < 0 or value > MAX_PWM_LEVEL:
raise ValueError("value must be between 0 and %s" % MAX_PWM_LEVEL)

map_level = (max_value * value) / MAX_PWM_LEVEL
with open(os.path.join(path, 'brightness'), 'w+') as f:
map_level = ((max_value-1) * value) // MAX_PWM_LEVEL
#-1 because if it puts max_value the duty cycle somehow becomes 0 (overflow)

#disable -> change level -> enable , as requested by documentation
with open(os.path.join(path, 'enable', ending), 'w+') as f:
f.write("0\n")

with open(os.path.join(path, 'level', ending), 'w+') as f:
f.write("%d\n" % map_level)

with open(os.path.join(path, 'enable', ending), 'w+') as f:
f.write("1\n")