Posts: 63
Threads: 14
Joined: Oct 2020
I am tweaking this code to get it ready for full integration into an animatronics costume setup. The individual pieces work. basically the GPIO triggers are limit switches. I am trying to build things such that if things slip or move that it will move forward if I hit the forward or backward button again and stop once the limit switch is triggered.
The way the libraries are it appears that it will stop as it is running through a for I range loop but will backup once that loop finishes if the gpio gets triggered.
I will keep researching and will probably sleep on things after I spend all evening researching different approaches on this conundrum. I just need to chew on things but more minds can help come up with unexpected solutions.
This is the code:
#!/usr/bin/python
import cwiid
import RPi.GPIO as GPIO
import sys
from time import *
import subprocess
import board
#this is for stepper motor controls, keyboard initiates movement, Button is limit switches
import keyboard
#gpiozero is the only library I have found that functions with the current pi and hardware setup I am using
from gpiozero import Button
#these are part of the Blinka libraries Adafruit has.
from adafruit_motorkit import MotorKit
from adafruit_motor import stepper
kit1 = MotorKit()
# this is for stepper motors and servo board
from board import SCL, SDA
import busio
from adafruit_pca9685 import PCA9685
i2c_bus = busio.I2C(SCL, SDA)
pca = PCA9685(i2c_bus)
pca.frequency = 50
# standard servo declearations for controls
from adafruit_servokit import ServoKit
kit = ServoKit(channels=16)
#12 and 13 are for one motion assembly backing up one full turn
button12 = Button(12)
button13 = Button(13)
#27 and 5 are for the other motion assembly
button27 = Button(27)
button5 = Button(5)
# while True loops endlessly. This can be run as a service using systemd or setup as an init.d script or as an rc.local script.
while True:
if button12.is_pressed:
print("button12 pressed")
for i in range (200):
kit1.stepper1.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)
if button13.is_pressed:
print("button13 pressed")
for i in range (200):
kit1.stepper1.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)
if keyboard.is_pressed('f'):
print("f is pressed")
for i in range (200):
kit1.stepper1.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)
if keyboard.is_pressed('b'):
print("b is pressed")
for i in range (200):
kit1.stepper1.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)
# This is for channel 2 stepper motor.
if button27.is_pressed:
print("button12 pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)
if button5.is_pressed:
print("button13 pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)
if keyboard.is_pressed('r'):
print("f is pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)
if keyboard.is_pressed('l'):
print("b is pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)
Posts: 63
Threads: 14
Joined: Oct 2020
OK I did some playing around and apparently I have to add a nested if statement with a break that calls back to detech the button press on the relevant gpio pin.
if keyboard.is_pressed('f'):
kit.servo[5].angle=10
print("f is pressed")
for I in range (3300):
if button13.is_pressed:
i = 3300
break
kit1.stepper1.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)if keyboard.is_pressed('b'):
kit.servo[5].angle=110
print("b is pressed")
for I in range (3300):
if button12.is_pressed:
i = 3300
break
kit1.stepper1.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)The thing I have to account for is if the system starts up bound at the edge of travel with GPIO activated at either end.
Posts: 1,566
Threads: 3
Joined: Mar 2020
What is the 200 loop for? Why not just move the stepper as long as a button is pressed and stop when it is released?
Posts: 6,200
Threads: 16
Joined: Feb 2020
Only allow motion when the associated limit switch is not pressed.
stepper1 = None
stepper2 = None
while True:
if keyboard.is_pressed('f') and not button12.is_pressed:
stepper1 = stepper.BACKWARD
elif keyboard.is_pressed('b') and not button13.is_pressed:
stepper1 = stepper.FORWARD
else:
stepper1 = None
if keyboard.is_pressed('r') and not button27.is_pressed:
stepper2 = stepper.BACKWARD
elif keyboard.is_pressed('l') and not button5.is_pressed:
stepper2 = stepper.FORWARD
else:
stepper2 = None
if stepper1:
kit1.stepper1.onestep(stepper1, style=stepper.DOUBLE)
if stepper2:
kit1.stepper2.onestep(stepper2, style=stepper.DOUBLE)I'm not sure if I have the stepper/key/button mapping correct. It would be a lot easier to keep things straight if you added a little structure to the code. In this example I use a DOF class to to keep the pertinent information for a stepper motor organized.
class DOF():
"""A single degree of freedom.
stepper - The stepper motor I control
forward - Function returns True if forward motion is requested
backward - Function returns True if backward motion is requested
fwd_limit - Function returns True if forward limit is reached
bwd_limit - Function returns True if backward limit is reached
"""
def __init__(self, stepper, forward, backward, fwd_limit=None, bwd_limit=None):
self.stepper = stepper
self.fowrard = forward
self.backward = backward
self.forward_limit = fwd_limit
self.backward_limit = bwd_limit
def move(self):
"""Move the stepper if move is requested and not prevented by limits"""
if self.forward():
if self.forward_limit is None or not self.forward_limit():
self.stepper.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)
if self.backward():
if self.backward_limit is None or not self.backward_limit():
self.stepper.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)
arm = DOF(
stepper=kit.stepper1,
forward=lambda:keyboard.is_pressed('f'),
backward=lambda:keyboard.is_pressed('b'),
fwd_limit=lambda:Button(12).is_pressed,
bwd_limit=lambda:Button(13).is_pressed
)
leg = DOF(
stepper=kit.stepper1,
forward=lambda:keyboard.is_pressed('l'),
backward=lambda:keyboard.is_pressed('r'),
fwd_limit=lambda:Button(27).is_pressed,
bwd_limit=lambda:Button(5).is_pressed
)
while True:
arm.move()
leg.move()
Posts: 63
Threads: 14
Joined: Oct 2020
(Jun-13-2021, 05:31 AM)bowlofred Wrote: What is the 200 loop for? Why not just move the stepper as long as a button is pressed and stop when it is released?
That is to back off the arm as it reached its limit end stop. I hit f it goes all the way back activates the gpio stops, then backs off 1.5 rotations. One rotation equates to 200 steps.
Posts: 63
Threads: 14
Joined: Oct 2020
(Jun-13-2021, 01:50 PM)deanhystad Wrote: Only allow motion when the associated limit switch is not pressed.
stepper1 = None
stepper2 = None
while True:
if keyboard.is_pressed('f') and not button12.is_pressed:
stepper1 = stepper.BACKWARD
elif keyboard.is_pressed('b') and not button13.is_pressed:
stepper1 = stepper.FORWARD
else:
stepper1 = None
if keyboard.is_pressed('r') and not button27.is_pressed:
stepper2 = stepper.BACKWARD
elif keyboard.is_pressed('l') and not button5.is_pressed:
stepper2 = stepper.FORWARD
else:
stepper2 = None
if stepper1:
kit1.stepper1.onestep(stepper1, style=stepper.DOUBLE)
if stepper2:
kit1.stepper2.onestep(stepper2, style=stepper.DOUBLE)I'm not sure if I have the stepper/key/button mapping correct. It would be a lot easier to keep things straight if you added a little structure to the code. In this example I use a DOF class to to keep the pertinent information for a stepper motor organized.
class DOF():
"""A single degree of freedom.
stepper - The stepper motor I control
forward - Function returns True if forward motion is requested
backward - Function returns True if backward motion is requested
fwd_limit - Function returns True if forward limit is reached
bwd_limit - Function returns True if backward limit is reached
"""
def __init__(self, stepper, forward, backward, fwd_limit=None, bwd_limit=None):
self.stepper = stepper
self.fowrard = forward
self.backward = backward
self.forward_limit = fwd_limit
self.backward_limit = bwd_limit
def move(self):
"""Move the stepper if move is requested and not prevented by limits"""
if self.forward():
if self.forward_limit is None or not self.forward_limit():
self.stepper.onestep(direction=stepper.FORWARD, style=stepper.DOUBLE)
if self.backward():
if self.backward_limit is None or not self.backward_limit():
self.stepper.onestep(direction=stepper.BACKWARD, style=stepper.DOUBLE)
arm = DOF(
stepper=kit.stepper1,
forward=lambda:keyboard.is_pressed('f'),
backward=lambda:keyboard.is_pressed('b'),
fwd_limit=lambda:Button(12).is_pressed,
bwd_limit=lambda:Button(13).is_pressed
)
leg = DOF(
stepper=kit.stepper1,
forward=lambda:keyboard.is_pressed('l'),
backward=lambda:keyboard.is_pressed('r'),
fwd_limit=lambda:Button(27).is_pressed,
bwd_limit=lambda:Button(5).is_pressed
)
while True:
arm.move()
leg.move()
The only way to move things is to use a for I in loop. The command syntax is very specific.
https://learn.adafruit.com/adafruit-dc-a...spberry-pi
Basically you are commanding a pca9685 chip using a library interface over i2c and it only responds a certain way using the library command framework as input.
It took me a while to figure that out for multiple controls and many more to find a compatible gpio control setup that actually worked. Too much in the python arena is changing and some stuff that worked once is not working now. Plus the pi OS updates for the 4 and whatever else is coming down the pike also throws a wrench in things if I go to recreate this months or years later. Then I throw a monkey wrench as I do not have proper schooling and just read what I can get a hold of and try to stick to a syntax that works for me. Once I get it working completely I then add loads of comments for documentation.
The idea is sound though and I could do a rewrite next go around and see what I can make work. I will try to get a picture of things so you get a better picture. As the script piece is just a control interface for the hardware that I am basically fabricating and adapting to make work for my setup...
Posts: 63
Threads: 14
Joined: Oct 2020
Jun-21-2021, 01:16 AM
(This post was last modified: Jun-21-2021, 01:16 AM by knoxvilles_joker.)
I did some more playing. I integrated another piece, that works. The stepper motors I had to do some tweaking.
#!/usr/bin/python
import cwiid
import RPi.GPIO as GPIO
import sys
from time import *
import subprocess
import board
import time
#this is for stepper motor controls, keyboard initiates movement, Button is limit switches
import keyboard
#gpiozero is the only library I have found that functions with the current pi and hardware setup I am using
from gpiozero import Button
#these are part of the Blinka libraries Adafruit has.
from adafruit_motorkit import MotorKit
from adafruit_motor import stepper
kit1 = MotorKit()
# this is for stepper motors and servo board
from board import SCL, SDA
import busio
from adafruit_pca9685 import PCA9685
i2c_bus = busio.I2C(SCL, SDA)
pca = PCA9685(i2c_bus)
pca.frequency = 50
# standard servo declearations for controls
from adafruit_servokit import ServoKit
kit = ServoKit(channels=16)
# this is for the new non-conflicting gyroscope
from adafruit_lsm6ds.lsm6ds33 import LSM6DS33
i2c = board.I2C()
sensor = LSM6DS33(i2c)
#12 and 13 are for one motion assembly backing up one full turn
button12 = Button(12)
button13 = Button(13)
#27 and 5 are for the other motion assembly
button27 = Button(27)
button5 = Button(5)
# while True loops endlessly. This can be run as a service using systemd or setup as an init.d script or as an rc.local script.
while True:
# sensor.gyro_rate=250
gyro_x, gyro_y, gyro_z=sensor.gyro
# rightxa=(((int(gyro_x--256)/(256--256))*180))
rightxa=(((int(gyro_x--5)/(5--5))*180))
# rightya=(((int(gyro_y--256)/(256--256))*180))
rightya=(((int(gyro_y--5)/(5--5))*180))
# rightza=(((int(gyro_z--256)/(256--256))*180))
rightza=(((int(gyro_z--5)/(5--5))*180))
rightx = round(rightxa)
righty = round(rightya)
rightz = round(rightza)
kit.servo[5].angle=rightx
kit.servo[14].angle=righty
kit.servo[7].angle=rightz
print("gx", rightx, "gy", righty, "gz", rightz)
time.sleep(0.6)
print("rx", gyro_x, "ry", gyro_y, "rz", gyro_z)
print("Gyro X:%.2f, Y: %.2f, Z: %.2f degrees/s" % (sensor.gyro))
if button12.is_pressed:
print("button12 pressed")
for i in range (200):
# kit1.stepper1.release()
kit1.stepper1.onestep(direction=stepper.BACKWARD, style=stepper.SINGLE)
if button13.is_pressed:
print("button13 pressed")
for i in range (200):
# kit1.stepper1.release()
kit1.stepper1.onestep(direction=stepper.FORWARD, style=stepper.SINGLE)
if keyboard.is_pressed('f'):
# kit.servo[14].angle=10
# kit.servo[5].angle=10
# kit.servo[7].angle=10
print("f is pressed")
for i in range (3300):
if button13.is_pressed:
i = 3300
break
kit1.stepper1.onestep(direction=stepper.BACKWARD, style=stepper.SINGLE)
if keyboard.is_pressed('b'):
# kit.servo[14].angle=170
# kit.servo[5].angle=170
# kit.servo[7].angle=170
print("b is pressed")
for i in range (3300):
if button12.is_pressed:
i = 3300
# kit1.stepper1.release()
break
kit1.stepper1.onestep(direction=stepper.FORWARD, style=stepper.SINGLE)
# This is for channel 2 stepper motor.
if button27.is_pressed:
print("button12 pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.FORWARD, style=stepper.SINGLE)
if i == 200:
kit1.stepper2.release()
if button5.is_pressed:
print("button13 pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.BACKWARD, style=stepper.SINGLE)
if i == 200:
kit1.stepper2.release()
if keyboard.is_pressed('r'):
print("f is pressed")
for i in range (3500):
if button27.is_pressed:
break
kit1.stepper2.onestep(direction=stepper.BACKWARD, style=stepper.SINGLE)
if i == 3500:
kit1.stepper2.release()
if keyboard.is_pressed('l'):
print("b is pressed")
for i in range (3500):
if button5.is_pressed:
break
kit1.stepper2.onestep(direction=stepper.FORWARD, style=stepper.SINGLE)
if i == 3500:
kit1.stepper2.release()
Posts: 63
Threads: 14
Joined: Oct 2020
I ended up having to add if statements within the range statements to trigger different behaviors based upon GPIO triggering and end range behavior. The other thing I found is that I either have a bad power supply or a bad stepper motor.
break is used to stop the progression of the range. I did not see much documentation in examples of what I was trying to do so it was playing with formatting to get the desired behavior.
Stepper 2 is for a blade gauntlet and stepper1 is for the pack. They are both rigged the same way.
The addiational code in the post above is for a gyroscope as I start integrating other pieces for the prototype build out.
# This is for channel 2 stepper motor.
if button27.is_pressed:
print("button12 pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.FORWARD, style=stepper.SINGLE)
if i == 200:
kit1.stepper2.release()
if button5.is_pressed:
print("button13 pressed")
for i in range (200):
kit1.stepper2.onestep(direction=stepper.BACKWARD, style=stepper.SINGLE)
if i == 200:
kit1.stepper2.release()
if keyboard.is_pressed('r'):
print("f is pressed")
for i in range (3500):
if button27.is_pressed:
break
kit1.stepper2.onestep(direction=stepper.BACKWARD, style=stepper.SINGLE)
if i == 3500:
kit1.stepper2.release()
if keyboard.is_pressed('l'):
print("b is pressed")
for i in range (3500):
if button5.is_pressed:
break
kit1.stepper2.onestep(direction=stepper.FORWARD, style=stepper.SINGLE)
if i == 3500:
kit1.stepper2.release()This pasted code piece is a functioning chunk for a limit travel assembly, but the triggering works.
I did find that a couple of the switches were wired to be triggered open instead of closed.
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