RE: MotorCape w/ uboot_overlay and Errors with Sysfs Entries/BBBW

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1

Hello,

I have just come across some issues:

  • What once worked does not work any longer
  • The source has changed a bit but I am receiving an error before the changes
  • I have some Python3 source and a server via Flask and HTML
    I am giving this source below to better make you understand what is happening on my end of the spectrum. Oh and…for some reason, the source only allows for non-like numerical values.

uname -a >>> Linux beaglebone 4.19.94-ti-r58
cat /etc/dogtag >>> BeagleBoard.org Debian Buster IoT Image 2020-04-06
…

For the uboot_overlay, here is the command to look it over w/ my overlay:

cat /boot/uEnv.txt >>> ###Overide capes with eeprom
uboot_overlay_addr0=/lib/firmware/BBORG_MOTOR-00A2.dtbo

oh and the source:

#!/usr/bin/python3

from flask import Flask, render_template
import Adafruit_BBIO.GPIO as GPIO
import Adafruit_BBIO.PWM as PWM
from time import sleep

class Motor:
def init(self, dir_pin, pwm_pin, pwm_freq):
self.dir_pin = dir_pin
self.pwm_pin = pwm_pin
self.value = 0

PWM.start(pwm_pin, 0, pwm_freq)
GPIO.setup(dir_pin, GPIO.OUT)

def set(self, value):
if value == self.value:
return

assert -100 <= value <= 100

if (value < 0) != (self.value < 0):

changing direction

PWM.set_duty_cycle(self.pwm_pin, 0)
GPIO.output(self.dir_pin, value < 0)

PWM.set_duty_cycle(self.pwm_pin, abs(value))
self.value = value

motor1 = Motor(dir_pin=“P8_18”, pwm_pin=“P9_16”, pwm_freq=1000)
motor2 = Motor(dir_pin=“P8_16”, pwm_pin=“P9_14”, pwm_freq=1000)
motor3 = Motor(dir_pin=“P8_14”, pwm_pin=“P8_13”, pwm_freq=1000)
motor4 = Motor(dir_pin=“P8_26”, pwm_pin=“P8_19”, pwm_freq=1000)

def set_motorOne(v1):
motor1.set(v1)

def set_motorTwo(v2):
motor2.set(v2)

def set_motorThree(v3):
motor3.set(v3)

def set_motorFour(v4):
motor4.set(v4)

app = Flask(name)

@app.route("/")
def homepage(title=“homepage”):
return render_template(“BootGoOne.html”, title=title)

def add_motors_routeOne(state, v1):
@app.route("/" + state, endpoint=state)
def handlerOne():
set_motorOne(v1)
if add_motors_routeOne == 0:
PWM.stop(“P9_16”)
else:
pass

return homepage(title=state)

add_motors_routeOne(“0”, 0)
add_motors_routeOne(‘40’, 40)
add_motors_routeOne(‘50’, 50)
add_motors_routeOne(‘60’, 60)
add_motors_routeOne(‘70’, 70)
add_motors_routeOne(‘80’, 80)
add_motors_routeOne(‘90’, 90)
add_motors_routeOne(‘100’, 100)

Okay…so:

  • When I add another ‘add_motors_routeOne’ as a separate call under another motor, I get some odd behavior.
    • For instance, ‘add_motors_routeTwo’, would begin to make issues with calling 'add_motors_routeTwo(“0”, 0) at the value 0.
      Anyway…the issue is that it begins to be a sysfs issue or an assertion error on my part.

Traceback (most recent call last):
File “Moto/motocape/MotorCapeOne/MotorCapeTwo.py”, line 92, in
add_motors_routeTwo(“0”, 0)
File “Moto/motocape/MotorCapeOne/MotorCapeTwo.py”, line 83, in add_motors_routeTwo
@app.route("/" + state, endpoint=state)
File “/usr/lib/python3/dist-packages/flask/app.py”, line 1250, in decorator
self.add_url_rule(rule, endpoint, f, **options)
File “/usr/lib/python3/dist-packages/flask/app.py”, line 66, in wrapper_func
return f(self, *args, **kwargs)
File “/usr/lib/python3/dist-packages/flask/app.py”, line 1221, in add_url_rule
‘existing endpoint function: %s’ % endpoint)
AssertionError: View function mapping is overwriting an existing endpoint function: 0

Above is where you can find my error with the current config. of the python3 source from above.

Seth

2

What did you do between it working and it not working ?

3

Hello,

Well…when I say working, I mean remedially working. Sysfs did return errors and I was always receiving the error about multiple values that are exactly the same.

I basically changed the source to handle four motors, added a server, and managed to adopt a “kill switch” in source via the Adafruit_BBIO.PWM functions and Adafruit_BBIO.GPIO functions.

Seth

P.S. One of the four motors seems nice but when I am making a quadruped, four motors are needed so far. Anyway, do you see an issue w/ the source as it may be as of now?

4

Oh and Hello Again,

I forgot to mention the major change.

So, instead of each motor handling its own PWM frequency in source along w/ duty_cycle, I had previously a method that handled one value that all motors were being controlled.

For instance:

def set_motorOne(v1):
motor1.set(v1)

def set_motorTwo(v2):
motor2.set(v2)

def set_motorThree(v3):
motor3.set(v3)

def set_motorFour(v4):
motor4.set(v4)

app = Flask(name)

@app.route("/")
def homepage(title=“homepage”):
return render_template(“BootGoOne.html”, title=title)

def add_motors_routeOne(state, v1):
@app.route("/" + state, endpoint=state)
def handlerOne():
set_motorOne(v1)
if add_motors_routeOne == 0:
PWM.stop(“P9_16”)
else:
pass

return homepage(title=state)

add_motors_routeOne(“0”, 0)
add_motors_routeOne(‘40’, 40)
add_motors_routeOne(‘50’, 50)
add_motors_routeOne(‘60’, 60)
add_motors_routeOne(‘70’, 70)
add_motors_routeOne(‘80’, 80)
add_motors_routeOne(‘90’, 90)
add_motors_routeOne(‘100’, 100)

  • The above source handles, what I thought would be, one motor and the peripherals of pwm and gpio.
  • The below source is what worked w/out the addition of three motors, separate values per motor, and no “failsafe.”
    def set_motors(v1, v2, v3, v4):

motor1.set(v1)
motor2.set(v2)
motor3.set(v3)
motor4.set(v4)

app = Flask(name)

@app.route("/")
def homepage(title=“homepage”):
return render_template(“BootGoOne.html”, title=title)

def add_motors_route(state, v1, v2, v3, v4):
@app.route("/" + state, endpoint=state)
def handlerOne():
set_motors(v1, v2, v3, v4)

if add_motors_routeOne == 0:

PWM.stop(“P9_16”)

else:
pass

return homepage(title=state)

add_motors_route(‘0’, 0)
add_motors_route(‘25’, 25)

and etc…

That is all.

Seth

5

Hello,

Do not worry about it. I made some random class function and the whole set up is in working order (remedial anyhow)…

Seth

P.S. BBBW still in the working ranks!