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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52 views

How to get RPi to generate a triangle wave, then outputting a PWM signal

I want my Raspberry Pi B+ Model to generate a triangle wave and output a PWM signal from one of the GPIO pins, but I'm not sure how to go about doing this. All I want it to do is add some small length ...
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0answers
13 views

PWM to control brightness on i2c LED backpack?

I have something similar to this, it works, but it's too bright! I am aware that LED brightness can be controlled by pulse width modulation, but I don't know if I can safely do that with an LED ...
0
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1answer
74 views

Control dc motor using GPIO.PWM problem

I'm trying to make a small remote controlled car with the raspberry pi and attached two small dc motors to it, using the L239D chip. When testing without the remote control (which is a simple android ...
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1answer
46 views

How to write to /dev/servoblaster from Python script?

I'm working on a RPI controlled quadcopter. The PWM is generated by ServoBlaster. I've written a Python script to control the motors' speed. Assume that I'm using GPIO4 to control the motor. If I want ...
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0answers
27 views

RPIO does not work on Python 3, only in Python 2.7

I've installed RPIO library to my RPI following these instructions: $ sudo apt-get install python-setuptools $ sudo easy_install -U RPIO I'm trying to run this code (test.py): from RPIO import PWM ...
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0answers
34 views

Is it possible to use GPIO's simultaneously?

I'm interested in using raspberry to control a number of brushless motors. PWM should be executed parallely to work in needed rate. As far as I've heard, RPi provides only consequent requests to ...
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0answers
33 views

Beginning with servos and PWM

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 ...
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1answer
94 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 ...
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1answer
66 views

Quadrocopter Motor Movement

A friend and I are trying to build a raspberry pi-powered quadrocopter. We've ordered four ESCs, four motors, and the Pi, but we're having trouble getting a motor to actually move. The motor makes a ...
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1answer
110 views

Can't PWM LED on pin 18

Using this code, I can't use PWM on the pi. It's modified off of a Linux user article. import time import RPi.GPIO as GPIO led = 18 GPIO.setmode(GPIO.BCM) GPIO.setup(led, GPIO.OUT) ...
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1answer
132 views

I2Cs for temperature senors and multiple PWM outs

EDIT: Rewrite, this is why you don't write questions after not sleeping for two days (wait what day is it?) I have a whole bunch of 12V 4 pin (pwr, grnd, tach, pwm) fans I'd like to manually control, ...
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1answer
840 views

Can I control this ESC/Brushless Motor with a Raspberry Pi and/or Arduino

My friend and I have been reading up on articles talking about controlling ESC/Brushless Motors from a Arduino or Raspberry Pi. Articles i've read give caution on the idea that controlling such ...
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3answers
184 views

Controlling a servo and playing sounds

I've got a serious problem about Pi. It is - I can play sound just fine with a python script either with: import pygame pygame.mixer.init() pygame.mixer.Sound("...").play() or: import os ...
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3answers
130 views

More Software PWM [duplicate]

I'm currently working on a project which requires more than one PWM signals for my LED drivers. I'm not looking for any additional hardware for this and so my focus is mainly on software PWM. Based ...
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0answers
73 views

Raspbian crashing after servo.stop_servo()

I have a servo connected to my RPi and I try PWM.Servo's capabilities. The program below does what it should - but after execution it crashes system (it doesn't respond to any input, no animations, ...
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1answer
134 views

How can I control the PWM via the sysfs

I want to set the PWM for some tests with a tricolored LED. I want to be able to set it up via the sysfs interfaces but I'm having a very hard time finding any information on how to do this. What is ...
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0answers
132 views

multiple PWM for led control

I'm creating a musical instrument based on capacitive sensors and I want to add some color to it. I would like to use PWM controlled LEDs because I want to make them dim and fade away nicelly. My ...
0
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1answer
848 views

Problem with PWM, running DC motor using L298 H bridge(using RPi.GPIO python module)

This picture shows the code i am using to run back and forth a dc motor for specified time and it works well, no problem with this.! Problem is here, as soon as i switch on my Pi and try to run the ...
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1answer
2k views

Controlling Multiple analog RGB 12V led strips

I need to control several (5 to 10) analog RGB strips which have a separate power supply at 12V or 24V. Just like this one for example. I need to control the intensity of each colour channel for each ...
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2answers
389 views

How to generate a PWM signal with Visual Basic? [closed]

Please help me to get PWM signal (three LEDs) from raspberry pi by using Visual Basic. I have a problem to generate pulse signal from raspberry pi wirelessly. What I want to do is using a program to ...
0
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1answer
67 views

controlling 50 piranha rgb leds

I'm a total newb looking for some help. I've got a bunch of piranha rgb leds. I wrote a program using wiringpi, hooked up 10x leds, and it all works fine. However, won't adding more leds be a problem? ...
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3answers
500 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 ...
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1answer
121 views

1 motor spradically stops when going forward

I've based my software on the "Linux User & Developer" (issue 132) robot tutorial (my source code can be found here) and hardware connections according to Adafruits PWM tutorial. The problem is ...
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1answer
275 views

PWM not found in Occidentalis v0.2

I'm trying to get my DC motor to work according to this tutorial from Adafruit: I'm running Occidentalis v0.2 (from day 1, which was some 4 months ago) and never had a similar issue. This is the ...
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0answers
113 views

Maximum Hardware PWM frequency

I am new to Raspberry Pi. I need to generate a PWM wave of frequency 25kHz. Is it possible to produce this with the hardware PWM? How would I change the duty cycle and how do I find the maximum ...
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0answers
737 views

Controlling a servo with hardware PWM using wiringPi

I tried controlling the servo with softPwm using the wiringPi Library but this made the servo stutter. Therefore I want to use the hardware PWM pin on the Raspberry Pi (GPIO18) with the wiringPi ...
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3answers
1k views

PWM input in Raspberry Pi

Is there a way to read a PWM signal from the pins on Raspberry Pi? I tried googling it, but I only found PWM output, and not input.
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2answers
529 views

What is the best way to increase digital i/o lines on Pi?

In one of my project I need 6 PWM outputs, 12 digital IO and around 6 analog inputs to be controlled by PI. What are some of the best options available to increase the IO capability of PI? For PWM, I ...
3
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1answer
625 views

Servo jumps on raspberry pi boot

I have just started using a servo to drive the front steering of a remote control car frame which i cannibalised. The steering works fine if i start it up and tune it however when i shut down the ...
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2answers
186 views

Software PWM as kernelspace module?

Has anyone tried doing a software PWM on the GPIO pins via a custom written module in kernel space? Wouldn't want to reinvent the wheel, so if there where tries, please forward me to them. Will ...
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1answer
369 views

How is the audio output controlled?

What hardware converts digital data to analog audio signal in Raspberry - past the codecs and the like, raw digital-to-analog conversion (be it using DAC, PWM, or any other means I'm not aware of)? Is ...
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3answers
497 views

Lighting a LED slowly with GPIO

What is a good way to make an LED turn on and off slowly using a Raspberry Pi? Im trying to hook up an led to become a Tardis lamp, but since the Pi doesnt have ADC/DAC, Im kind of stuck. What are ...
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2answers
852 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 ...
0
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1answer
1k views

Control servo with raspberry pi

I have the following servo I would like to make a small self balancing robot with it. I am having trouble with figuring out how to control it with PWM using pulses to decide what position to move it ...
0
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2answers
2k views

Where is the PWM pin located exactly on the board?

Can someone point me to exactly where the PWM pin is on the board and how I can hook this thing up visually as I'm totally lost as to what I would need to make this run. Also what is the snippet of ...
6
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2answers
4k 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. ...
2
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2answers
432 views

How to program pwm an arbitrary waveform to generate infrared stream

I've use a pic to create IR patterns to modulate frequencies (37kHz or 58kHz) to control different devices. I'd like to move as much as possible to a RPi. I will use a pic to generate the 37kHz or ...
3
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2answers
660 views

Interfacing with an RC receiver using PWM on the GPIOs

I've been struggling for a few days and haven't managed to turn up a lot on the internet. I'm looking to READ from the PWM output of an RC receiver through one of the GPIO's on the RPi. I've read ...
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1answer
2k views

How can I use the hardware PWM? [duplicate]

Possible Duplicate: Using Raspberry Pi without a Linux OS? I would like to generate a PWM, but I don't want to use a Linux distribution; I would like to have a simple code. Is there any ...
29
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3answers
34k 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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8answers
18k views

How can I control an RC servo?

I'd like to control a small RC servo (5 V, 500 mA) from the GPIO pins via Python. Hardware What are the required electrical connections? Can I connect multiple servos to the Raspberry ...