Questions tagged [pwm]

Pulse-Width Modulation (PWM) is a technique used for controlling the power given to electrical devices. The average power supplied is controlled by rapidly turning the supply on and off. Questions here concern driving PWM outputs from the Raspberry Pi.

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104
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5answers
238k views

Can I use the GPIO for pulse width modulation (PWM)?

Can I use the GPIO as a pulse-width modulation output? If so, how would I go about doing it and how many concurrent, distinct PWM outputs can I have?
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2answers
2k views

How can Rpi move a Servo motor using a GPIO pin in PWM mode?

iam new to raspberry pi and i got an error while a running servo motor in my object detection script i need to run the servo whenever my if condition is true so the same pin run multiple times if ...
24
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3answers
87k views

Control Hardware PWM frequency

I'm using the hardware PWM output with wiringpi. It provides the function pwmSetClock that should make it possible to change the frequency. (https://projects.drogon.net/raspberry-pi/wiringpi/functions/...
1
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1answer
638 views

How can Rpi4B python UART talk to XY PWM Signal Generators?

Currently I am trying to automate a coil winding machine using stepper motors. I wrote a Python code to send frequencies to the stepper motors. But for some reason, the frequencies produced by ...
-1
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1answer
258 views

Sg 5010 servo 360 degree modification not working [closed]

As per the video tutorials out there, I opened the motor, took out the potentiometer and measured its resistance at max. Its a b5k pot so it measured 5kohm I put 2.5k ohm from each pin (s and -) and ...
0
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2answers
890 views

How to use Rpi python to read/write/convert, to/from Arduino PPM and PWM servo control signals?

I want to create a python equivalent of the RCPulseIn library for arduino that does all the same functions of the library. I have written up a code that has lots of errors, but has sort of a framework ...
1
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2answers
4k views

How to create multiple GPIO pwm waveforms that are in sync using pigpio for trapezoidal motor control?

Explanation I am using a Rpi 2 model B, and PIGPIO to generate PWMs. Goal is to run a three phase permanent magnet synchronous motor using the Rpi 2 with IRAMS10UP60A. Need 6 repeatable waveforms to ...
0
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1answer
5k views

Controlling a brushed motor ESC from the Raspberry Pi

I've tried solutions from similar problems, but none of them gave me any usable results. I'm trying to control those http://www.ebay.com/itm/311177661450 electronic speed controls (ESCs) with ...
8
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2answers
17k views

Driving PWM output frequency

After many hours of fruitless searching and reading, I still didn't have a complete understanding of how and why to output specific frequencies from the hardware PWM pin on the RPi without using ...
4
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2answers
2k views

What is the best way to increase digital I/O lines on Pi?

In one of my projects I need six PWM outputs, 12 digital I/O and around six analog inputs to be controlled by a Raspberry Pi. What are some of the best options available to increase the I/O capability ...
3
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4answers
6k views

How to control a Traxxas XL-5 ESC directly from the GPIO?

I am trying to control the ESC (Electronic Speed Control) of my Traxxas RC car with my raspberry pi (rev.2). I have been looking through the internet and while I can find some projects that seem to ...
3
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1answer
268 views

PWM Servo - Check availability

I'm writing a program which requires Servo's basic movement. Here's the code: import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setup(18, GPIO.OUT) pwm = GPIO.PWM(18, 100) pwm.start(5) ...
1
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1answer
1k views

No module named 'adafruit_circuitpython_servokit' [closed]

I have a Adafruit PWM hat and I am trying to run play around with some servos. However, when I run this line: from adafruit_servokit import ServoKit It returns: No module named '...
2
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1answer
1k views

Accessing pwm module without root permissions

I am trying to use the hardware PWM module on my pi 3 by writing to the /sys/class/pwm/pwmchip0 directory (which I think is just a symbolic link to sys/devices/platform/soc/3f20c000.pwm/pwm/pwmchip0). ...
10
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5answers
14k views

3.5 mm jack starts to “hiss” after sound is played

I'm having the following issues with my amp on the Raspberry Pi 2, Model B. Boot up the Pi, everything sounds great. Play a sound byte through the Pi (using ALSA) Speakers hiss regardless of PCM ...
7
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1answer
1k views

Raspberry Python Libraries

I am currently working with a Raspberry Pi (Model B+) and have some experience with Arduino (and it's derivates). Now, there are three Libs for GPIO access with Python for the Pi: WiringPi (...
5
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1answer
2k views

PWM Control on Raspberry PI

Alright so I understand this question is fairly saturated, but my use in pwm is for two differing pieces of hardware. (Sourced from: https://www.modmypi.com/blog/raspberry-pi-gpio-en-franais) From ...
2
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1answer
8k views

How to initialize an ESC with Python code [duplicate]

I can't make my brushless motor move; it kepps on beeping. I have connected it to an electronic speed control (ESC) and am trying to signal the ESC from the GPIO pins of Raspberry pi B+. How do I ...
2
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4answers
3k views

Can raspberry pi generate many 40khz square wave on GPIO pin using package supported from simulink?

I want generate many 40khz square wave on GPIO pin by simulink but when I try generate more than 10khz is oscillascope not display accurately. I must fix this problem how ? I think supported language ...
0
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1answer
1k views

HC-SR04 ultrasonic sensor reading becomes highly unusable when PWM is active

Good day I am trying to sample distance using a sonar/ultrasonic sensor for altitude measurement. When the PWM is not active, the sensor gives accurate measurements in centimeters, however with the ...
2
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2answers
3k views

controlling two motors with an L293D

Update: Can I possibly use the TLC5940 to control two motors? So there is a lot of talk about controlling two motors. My plan is two build a RPi robot and at minimum I need to have it control ...
2
votes
2answers
2k views

Is it possible to expand the PWM signal?

I'm looking at the WS2812B LEDs and I've noticed that it is possible to control the LEDs by an external library (https://learn.adafruit.com/neopixels-on-raspberry-pi/software). But, this only drives a ...
2
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2answers
1k views

AC mains dimmer dimming 7W LED lamp problem (RpiZero + MPDM V4.1)

I'm trying to dim a 7W LED with a Raspberry Pi Zero for home automation. However it doesn't work as expected. I followed this tutorial : https://www.youtube.com/watch?v=wqY4-gHqvZI . I have the exact ...
1
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3answers
542 views

I'm looking for a serial input type “polychromatic” LED as an output for my raspberry pi. Does such a device exist?

Forgive any potential neologisms, but I would like to acquire a light that can, say, display 64-256 different shades of color based off of a digital numerical input signal? It can be a usb light, but ...
1
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3answers
147 views

How to use Rpi python GPIO pins in PWM output mode to create PWM signals?

I was trying to understand PWM when I ran across this example: import RPi.GPIO as GPIO GPIO.setmode(GPIO.BOARD) GPIO.setup(12, GPIO.OUT) p = GPIO.PWM(12, 0.5) p.start(1) input('Press return to stop:')...
1
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1answer
130 views

Control PWM duration with python

I need to control the PWM module on the raspberry pi. I’m now familiar with pigpio, and with hardware_PWM. However, I did not find anywhere where I can control the total duration of the PWM. Example: ...
0
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0answers
37 views

Raspberry Pi3 - Controlling 4 DC motors

I need to feed 4 DC motors of 5V on my Raspberry Pi 3 Model B using PWM (Pulse Width Modulation). Currently, I have the next components: 2 NPM transistors, 1 L293D integrated circuit, resistors (220 ...
0
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1answer
133 views

Servo motor keep shaking while using software PWM to drive

Greet everyone, I am using JavaScript with pigpio to develop my learning project. How come my servo motor keeps shaking when I drive it by program PWM? codes are posted as follow: var servo1GPIO ...
0
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3answers
4k views

Raspberry pi Software Driven PWM using C++

I am using software driven PWM which is capable of outputting a PWM signal on any GPIO pins. Following Gordon's page. I am trying to run 2 DC motors I am using GPIO pin 18 also knowing that it is ...
0
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1answer
26 views

Controlling 4 servo motors through hardware PWM

I am working on a some time-critical system that will run image processing and controlling 4 SG90 servo motors. In short, I will do visual-servoing. Since I will do visual servoing, I don't want to ...
0
votes
1answer
227 views

Triggering of MAPIR using PWM signal

I am currently trying to trigger a MAPIR Survey3 NDVI Camera with a PWM Signal. The camera is connected via this HDMI trigger cable. For the camera to trigger I need a 2 ms PWM signal. I have given ...
0
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0answers
160 views

Electronics Newbies's Guide to Setup Adafruit PCA9685 16 Channel Servo Driver for Raspberry Pi

As a way into getting myself back into learning more about electronics I'm trying to figure out how not to screw up configuring an Adafruit 16-Channel 12-bit PWM/Servo Driver with my pi. It's been ...