Tag Archives: Servo

In this video I show how to use both cores on the Raspberry Pi Pico W. We will explore an example using threading where we will operate 2 LED and a servo.

from machine import Pin
import time
import _thread
import SERVO

greenPin=14
redPin=15
servoPin=17

LED=""

redLED=Pin(redPin,Pin.OUT)
greenLED=Pin(greenPin,Pin.OUT)

delOn=.1
delOff=.1
myServo=SERVO.servo(servoPin)
running =True

def othCore(del1,del2):
    global LED
    while True:
        if LED=="RED":
            redLED.value(1)
            time.sleep(del1)
            redLED.value(0)
            time.sleep(del2)
        if LED=="GREEN":
            greenLED.value(1)
            time.sleep(del1)
            greenLED.value(0)
            time.sleep(del2)
_thread.start_new_thread(othCore,(delOn,delOff))
time.sleep(.25)
while True:
    LED="RED"
    for i in range(0,180,1):
        myServo.pos(i)
        time.sleep(.01)
    LED="GREEN"
    for i in range(180,0,-1):
        myServo.pos(i)
        time.sleep(.01)

from machine import Pin

import time

import _thread

import SERVO

greenPin=14

redPin=15

servoPin=17

LED=""

redLED=Pin(redPin,Pin.OUT)

greenLED=Pin(greenPin,Pin.OUT)

delOn=.1

delOff=.1

myServo=SERVO.servo(servoPin)

running =True

def othCore(del1,del2):

global LED

while True:

if LED=="RED":

redLED.value(1)

time.sleep(del1)

redLED.value(0)

time.sleep(del2)

if LED=="GREEN":

greenLED.value(1)

time.sleep(del1)

greenLED.value(0)

time.sleep(del2)

_thread.start_new_thread(othCore,(delOn,delOff))

time.sleep(.25)

while True:

LED="RED"

for i in range(0,180,1):

myServo.pos(i)

time.sleep(.01)

LED="GREEN"

for i in range(180,0,-1):

myServo.pos(i)

time.sleep(.01)

MicroPython, Raspberry Pi Pico

Servo Library for the Raspberry Pi Pico W in MicroPython

April 23, 2024 admin

In this lesson we demonstrate how to create a custom library on the Raspberry Pi Pico W to control a servo. We create a servo class, and then show how to use it as a library in future programs.

class servo:
    def __init__(self,sPin):
        import machine
        self.servoPin=sPin
        self.obj=machine.PWM(machine.Pin(self.servoPin))
        self.obj.freq(50)
    
    def pos(self,angle):
        writeVal=6553/180*angle+1638
        self.obj.duty_u16(int(writeVal))

class servo:

def __init__(self,sPin):

import machine

self.servoPin=sPin

self.obj=machine.PWM(machine.Pin(self.servoPin))

self.obj.freq(50)

def pos(self,angle):

writeVal=6553/180*angle+1638

self.obj.duty_u16(int(writeVal))

MicroPython, Raspberry Pi Pico

Calibrating Joystick to Show Positional Angle in MicroPython on the Raspberry Pi Pico W

March 5, 2024 admin

In this Video Lesson we show how to calibrate a joystick to report Angular Position. We do this using MicroPython on a Raspberry Pi Pico W. For your convenience, the code is included below.

import machine
import time
import math
hPin=27
vPin=26
hJoy= machine.ADC(hPin)
vJoy= machine.ADC(vPin)
while True:
    hVal=hJoy.read_u16()
    vVal=vJoy.read_u16()
    
    hCal=int(-.00306*hVal+100.766)
    vCal=int(.00306*vVal-100.766)
    
    deg=math.atan2(vCal,hCal)*360/2/math.pi
    if hCal==0:
        hCal=1
    if deg<0:
        deg=deg+360
    
    mag=math.sqrt(hCal**2+vCal**2)
    if mag<=4:
        hCal=0
        vCal=0
    
    print(hCal,vCal,deg)
    time.sleep_ms(200)

import machine

import time

import math

hPin=27

vPin=26

hJoy= machine.ADC(hPin)

vJoy= machine.ADC(vPin)

while True:

hVal=hJoy.read_u16()

vVal=vJoy.read_u16()

hCal=int(-.00306*hVal+100.766)

vCal=int(.00306*vVal-100.766)

deg=math.atan2(vCal,hCal)*360/2/math.pi

if hCal==0:

hCal=1

if deg<0:

deg=deg+360

mag=math.sqrt(hCal**2+vCal**2)

if mag<=4:

hCal=0

vCal=0

print(hCal,vCal,deg)

time.sleep_ms(200)

Jetson Xavier NX

Jetson Xavier NX Lesson 8: Controlling Dual Pan/Tilt Raspberry Pi Cameras

July 8, 2020 admin

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In this lesson we show how to independently control two Raspberry Pi Cameras using servo controlled pan/tilt brackets. This work will serve as the foundation for allowing us to create cameras that scan a room and locate objects of interest.

In this lesson, I am using two pan/tilt camera mounts. You can get the gear I am using on amazon HERE. I suggest purchasing two units.

Then, we also need two Version two raspberry pi cameras. I like the following ones, because they include a neat little acrylic case, and the long cable, which makes it work much better on the pan/tilt bracket. You can get the cameras HERE.

If you do not have a Jetson Xavier NX yet, you can pick up the gear I am using below:

First, you will need the Jetson Xavier NX, which you can get HERE:
You will want a quality, large SD card, I have very good luck with this one HERE:
You will need a camera. I have found that the Jetson Xavier NX works very well with most Logitech Webcams, but these cameras are a little hard to find right now. I suggest the best option if you do not have a logitech webcam is to get the Raspberry Pi Version 2 camera, which works very well. You can pick the camera up HERE.
It is optional, but I have found that it is nice to have an extra, longer cable for the Raspberry Pi camera, which is available HERE. Also, a small case/stand for the camera is nice and you can get the one I use HERE.
The Jetson Nano has a slot for a SSD drive. I really like having the SSD drive attached, and makes it much easier to keep your work backed up. The projects in these lessons will work fine with just the SD card, but if you like, the SSD drive makes life easier (note even with SSD drive, you will still need the SD card above). You can get the SSD drive I am using HERE.
You can use USB keyboard and mouse, but I like to preserve my USB slots for other things, so like using a wireless keyboard and mouse. This is optional, but I have found these work well on the Jetson Xavier NX, and you can get what I am using HERE.
You will need an HDMI cable and monitor, which you probably already have.

import cv2
import numpy as np
import time
from adafruit_servokit import ServoKit
print(cv2.__version__)
timeMark=time.time()
dtFIL=0

kit=ServoKit(channels=16)

tilt=90
pan=90
dTilt=10
dPan=1

kit.servo[0].angle=pan
kit.servo[1].angle=tilt
kit.servo[2].angle=pan
kit.servo[3].angle=tilt

width=720
height=480
flip=2
font=cv2.FONT_HERSHEY_SIMPLEX
camSet1='nvarguscamerasrc sensor-id=0 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'
camSet2='nvarguscamerasrc sensor-id=1 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

#camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'
#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink'
cam1=cv2.VideoCapture(camSet1)
cam2=cv2.VideoCapture(camSet2)
while True:
    _, frame1 = cam1.read()
    _, frame2 = cam2.read()
    frame3=np.hstack((frame1,frame2))
    dt=time.time()-timeMark
    timeMark=time.time()
    dtFIL=.9*dtFIL + .1*dt
    fps=1/dtFIL
    cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1)
    cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2)
    print('fps: ',fps)
    #cv2.imshow('myCam1',frame1)
    #cv2.imshow('myCam2',frame2)
    cv2.imshow('comboCam',frame3)
    cv2.moveWindow('comboCam',0,450)
    kit.servo[0].angle=pan
    kit.servo[2].angle=pan
    pan=pan+dPan
    if pan>=179 or pan<=1:
        dPan=dPan*(-1)
        tilt=tilt+dTilt
        kit.servo[1].angle=tilt
        kit.servo[3].angle=tilt
        if tilt>=169 or tilt<=11:
            dTilt=dTilt*(-1)
    if cv2.waitKey(1)==ord('q'):
        break
cam.release()
cv2.destroyAllWindows()

import cv2

import numpy as np

import time

from adafruit_servokit import ServoKit

print(cv2.__version__)

timeMark=time.time()

dtFIL=0

kit=ServoKit(channels=16)

tilt=90

pan=90

dTilt=10

dPan=1

kit.servo[0].angle=pan

kit.servo[1].angle=tilt

kit.servo[2].angle=pan

kit.servo[3].angle=tilt

width=720

height=480

flip=2

font=cv2.FONT_HERSHEY_SIMPLEX

camSet1='nvarguscamerasrc sensor-id=0 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

camSet2='nvarguscamerasrc sensor-id=1 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

#camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'

#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink'

cam1=cv2.VideoCapture(camSet1)

cam2=cv2.VideoCapture(camSet2)

while True:

_, frame1 = cam1.read()

_, frame2 = cam2.read()

frame3=np.hstack((frame1,frame2))

dt=time.time()-timeMark

timeMark=time.time()

dtFIL=.9*dtFIL + .1*dt

fps=1/dtFIL

cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1)

cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2)

print('fps: ',fps)

#cv2.imshow('myCam1',frame1)

#cv2.imshow('myCam2',frame2)

cv2.imshow('comboCam',frame3)

cv2.moveWindow('comboCam',0,450)

kit.servo[0].angle=pan

kit.servo[2].angle=pan

pan=pan+dPan

if pan>=179 or pan<=1:

dPan=dPan*(-1)

tilt=tilt+dTilt

kit.servo[1].angle=tilt

kit.servo[3].angle=tilt

if tilt>=169 or tilt<=11:

dTilt=dTilt*(-1)

if cv2.waitKey(1)==ord('q'):

break

cam.release()

cv2.destroyAllWindows()

Jetson Xavier NX

Jetson Xavier NX Lesson 7: Connecting and Controlling Servos

July 1, 2020 admin

In this lesson we show you how to control a pan/tilt camera bracket with the NVIDIA Jetson Xavier NX. We go through the physical build of the bracket, how to connect the circuit, and then how to program the servos. We use the Adafruit circuitpython library, and show how to download and use the library. If you want to play along at home, you can pick the pan/tilt bracket and servos up HERE, and you can grab a couple of Raspberry Pi cameras HERE.

Below is the simple code for moving the servo using the Jetson Xavier NX:

import time
from adafruit_servokit import ServoKit
kit=ServoKit(channels=16)
tilt=125
pan=0
kit.servo[0].angle=pan
kit.servo[1].angle=tilt
for i in range(0,180):
    kit.servo[0].angle=i
    time.sleep(.05)
for i in range(180,0,-1):
    kit.servo[0].angle=i
    time.sleep(.05)
for i in range(45,180):
    kit.servo[1].angle=i
    time.sleep(.05)
for i in range(180,0,-1):
    kit.servo[1].angle=i
    time.sleep(.05)

import time

from adafruit_servokit import ServoKit

kit=ServoKit(channels=16)

tilt=125

pan=0

kit.servo[0].angle=pan

kit.servo[1].angle=tilt

for i in range(0,180):

kit.servo[0].angle=i

time.sleep(.05)

for i in range(180,0,-1):

kit.servo[0].angle=i

time.sleep(.05)

for i in range(45,180):

kit.servo[1].angle=i

time.sleep(.05)

for i in range(180,0,-1):

kit.servo[1].angle=i

time.sleep(.05)

Technology Tutorials

Tag Archives: Servo

MicroPython MultiCore Programming on the Raspberry Pi Pico Using Threading

Servo Library for the Raspberry Pi Pico W in MicroPython

Calibrating Joystick to Show Positional Angle in MicroPython on the Raspberry Pi Pico W

Jetson Xavier NX Lesson 8: Controlling Dual Pan/Tilt Raspberry Pi Cameras

Jetson Xavier NX Lesson 7: Connecting and Controlling Servos

Making The World a Better Place One High Tech Project at a Time. Enjoy!