Problems with Adafruit_BBIO.PWM (reference issue #169) #185
Description
I've had severe problems with PWM on my BBB. I've just re-flashed my board with the latest image, then ran apt-get update. My python code gets the same output stated above. Here's the code:
import Adafruit_BBIO.PWM as PWM
servo_pin = "P8_13"
duty_min = 3
duty_max = 14.5
duty_span = duty_max - duty_min
#PWM.start(servo_pin, 50, 1000, 1)
#PWM.start(servo_pin, 50)
PWM.start(servo_pin, (100-duty_min), 60.0)
while True:
angle = raw_input("Angle (0 to 180 x to exit):")
if angle == 'x':
PWM.stop(servo_pin)
PWM.cleanup()
break
angle_f = float(angle)
duty = 100 - ((angle_f / 180) * duty_span + duty_min)
PWM.set_duty_cycle(servo_pin, duty)
The output is
Your code is running at http://localhost.
Important: use os.getenv(PORT, 8080) as the port and os.getenv(IP, 0.0.0.0) as the host in your scripts!
Traceback (most recent call last):
File "/var/lib/cloud9/senior_design/pwm.py", line 10, in <module>
PWM.start(servo_pin, (100-duty_min), 60.0)
RuntimeError: Problem with a sysfs file
Process exited with code: 0
I next tried to test PWM using the BoneScript library with the following code. The first time I run the BoneScript version, it does work. However, if I re-run the code with no change or by changing frequency, duty cycle, or port PWM does not output again, and the running PWM stops. It does not work again until I restart the board. UPDATE - It will output again after I run the pin PWM config given above (and pasted below)
var b = require('bonescript');
b.pinMode('P9_14', b.OUTPUT);
b.analogWrite('P9_14', 0.7, 2000.0, printStatus);
function printStatus(x) {
console.log('x.err = ' + x.err);
}
I've been reading through this thread and to help out here's additional stuff I've run.
debian@beaglebone:/var/lib/cloud9$ for i in `find /sys/devices/platform/ocp/ -type f |grep pinmux |grep state$|sort -n`; do echo $i: `cat $i`; done
/sys/devices/platform/ocp/ocp:P8_07_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_08_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_09_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_10_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_11_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_12_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_13_pinmux/state: pwm
/sys/devices/platform/ocp/ocp:P8_14_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_15_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_16_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_17_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_18_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_19_pinmux/state: default
/sys/devices/platform/ocp/ocp:P8_26_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_11_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_12_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_13_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_14_pinmux/state: gpio
/sys/devices/platform/ocp/ocp:P9_15_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_16_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_17_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_18_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_21_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_22_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_23_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_24_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_26_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_27_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_30_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_41_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_42_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_91_pinmux/state: default
/sys/devices/platform/ocp/ocp:P9_92_pinmux/state: default
Next, I ran the suggested code above. I found that this will restore PWM to the bonescript code, but I still get the same Problem with a sysfs file error from the Python code.
debian@beaglebone:/var/lib/cloud9$ config-pin -q p9.14
P9_14 Mode: gpio Direction: out Value: 0
debian@beaglebone:/var/lib/cloud9$ config-pin p9.14 pwm
debian@beaglebone:/var/lib/cloud9$ config-pin -q p9.14
P9_14 Mode: pwm
debian@beaglebone:/var/lib/cloud9$
debian@beaglebone:/var/lib/cloud9$ config-pin -q p9.16
P9_16 Mode: default Direction: in Value: 0
debian@beaglebone:/var/lib/cloud9$ config-pin p9.16 pwm
debian@beaglebone:/var/lib/cloud9$ config-pin -q p9.16
P9_16 Mode: pwm
debian@beaglebone:/var/lib/cloud9$
debian@beaglebone:/var/lib/cloud9$ config-pin -q p8.19
P8_19 Mode: default Direction: in Value: 0
debian@beaglebone:/var/lib/cloud9$ config-pin p8.19 pwm
debian@beaglebone:/var/lib/cloud9$ config-pin -q p8.19
P8_19 Mode: pwm
debian@beaglebone:/var/lib/cloud9$
debian@beaglebone:/var/lib/cloud9$ config-pin -q p8.13
P8_13 Mode: pwm
debian@beaglebone:/var/lib/cloud9$ config-pin p8.13 pwm
debian@beaglebone:/var/lib/cloud9$ config-pin -q p8.13
P8_13 Mode: pwm