29 votes
Accepted

Robot never goes straight

I'm posting this as an answer because it is the answer. You can't. As @BendingUnit22 mentions, you are attempting "open loop" control. Noise and variations will mean that your robot will never ...
Chuck's user avatar
  • 16k
10 votes
Accepted

How can we use the accelerometer for altitude estimation?

The barometer carried on the pixhawk has an altitude resolution of 10 cm. If that isn't enough, you could write a kalman filter that uses the accelerometer data in the prediction step and the ...
holmeski's user avatar
  • 1,853
6 votes

ROS on Raspberry Pi Model 2: UbuntuARM vs ROSBerryPi

The ROSBerryPi page is quite outdated, you actually can install prebuilt ROS Groovy binaries on Raspbian. You will be better off installing prebuilt ROS binaries rather than building from source on ...
hammer's user avatar
  • 106
6 votes

Robot never goes straight

Since the open-closed loop issue is already mentioned, I will give a comment to the "I once tried to run a dc-motor without a load". Yes you might damage your motor with this but you can also damage ...
TobiasK's user avatar
  • 1,657
6 votes
Accepted

How to measure pull force on a (kite) rope?

The component you highlighted is called a tensile load cell. You could buy one from a supplier, but it probably would be cheaper to buy a cheap digital hanging scale and taking the sensor out of it - ...
Pete Kirkham's user avatar
5 votes
Accepted

L293D won't turn motor backwards

The motor driver chip you state you are using, the L293D, is a "quadruple half H driver." This means that, instead of two full H circuits capable of driving a motor forward and reverse, you have four ...
Chuck's user avatar
  • 16k
5 votes
Accepted

Arduino or Raspberry Pi?

For interfacing with a camera, I would recommend the Pi. The reason is that the AVR in the Arduino is an ordinary processor, whereas the Broadcom SoC in the Pi was originally designed for multimedia. ...
Mark's user avatar
  • 331
5 votes
Accepted

What is the difference between ROSberry Pi builds?

Well this is embarrassing. I didn't realize they are in fact different distributions not variants. Also found the page where you can find out more about them: http://wiki.ros.org/Distributions
Xavier Guay's user avatar
5 votes
Accepted

Why to combine a Raspberry Pi (or similar board computer) and an Arduino for controlling motors?

The reason is Clock on the Raspberry Pi. Note that the raspberry is powerful but not that powerful that it can run an OS and simultaneously give you precisely timed PWM outputs. I assume that you'll ...
Kartik Madhira's user avatar
5 votes
Accepted

How to handle power distribution on a robot?

For power management, you can use either a DC/DC Convertor, a linear regulator, or a combination of the two. DC/DC Converter A DC/DC Converter changes DC voltage levels. Three common types are: ...
Mepix's user avatar
  • 295
4 votes
Accepted

Best power solution for my robot

I agree with @Greenonline 's recommendation regarding LiPo batteries along with his warnings on battery care. It seems you will need a fairly small battery, considering your current requirements (...
George ZP's user avatar
  • 550
4 votes

Should I use an arduino to control my balancing robot's motors?

If you want to have a good balancing, PID loop timing is very important. Standard Raspberry OS, like Raspbian can't guarantee you any precise timing, so once your loop period may be 10ms, once it can ...
mactro's user avatar
  • 953
4 votes
Accepted

Are robot's codes usually compiled or interpreted?

Robots tend to be portable devices powered by batteries. Portable battery operated devices tend to use embedded processors with limited power and memory. Compiled code has several advantages over ...
st2000's user avatar
  • 506
4 votes

PID Control: Is adding a delay before the next loop a good idea?

Don't disengage your controller. The purpose of a controller is not only to steer your system to the desired setpoint according to a predetermined dynamical response but also to counteract potential ...
Ugo Pattacini's user avatar
3 votes

Smart Home Model with Raspberry Pi

Though, there is not much information about your servos let's assume that they consume at least 1A each. This value will probably be higher given that you want to move doors and that requires torque. ...
Bence Kaulics's user avatar
3 votes

Arduino or Raspberry Pi?

The only issue with having the off-board controller is that the commands to the quad-rotor might lag, because of 1. range to controller or 2. the complexity of image processing code. With that said I ...
sgk525's user avatar
  • 31
3 votes

Need help regarding odometry using Encoder motor and raspberry pi

You could maybe use Matlab to plot the position of your vehicle? This is how I'm trying to do that: I have a 'logging'-program running on the Raspberry Pi that counts each sampling time the pulses ...
Eva's user avatar
  • 155
3 votes
Accepted

Do I need the 5V to 3.3V level shifter?

The Roombots example you posted does not use a level shifter because they are using the Create USB cable to talk to the robot. If you are planning to use this cable, you do not need the level shifter. ...
Steve's user avatar
  • 942
3 votes
Accepted

Quadcopter controlled by Raspberry Pi

The easiest way to do this would be using UART for serial communication. The CC3D has TX/RX/GND pins which you connect to Raspberry Pi. Now you will need some sort of protocol or data framing to ...
heethesh's user avatar
  • 188
3 votes

ROS + SLAM + kinect. which platform to use?

There are several platforms possible, depending on your experience level and needs. If you are comfortable working with the Raspberry Pi or the Beagle Bone... the next step up might be the Jetson TX1 ...
Mepix's user avatar
  • 295
3 votes
Accepted

Nuc, custom pc or raspberry pi?

Edit: With the new information in your post I would highly recommend going for more computing power than you think you need. It is always to have a little extra wriggle room than to be stuck with not ...
sa_leinad's user avatar
  • 207
3 votes

What other equipment or hardwares I should buy along with raspberry pi

First, it is important to understand the differences between the Arduino and the Raspberry Pi. You can read more here and here. The Arduino is a microcontroller. It is a specialized board that ...
Mepix's user avatar
  • 295
3 votes

How to access Raspberry Pi over wifi?

To access your RPi over the WiFi, you can use any SSH client like PuTTY. Once you have established a connection between your RPi and computer, then you can control GPIOs through a TCP connection. ...
Franky's user avatar
  • 536
3 votes
Accepted

Recommended building materials for building a robot WITHOUT 3D printer?

With consideration cheap, strong enough, not ugly and easy to shape, then my recommendation is you can use clipboard. I have seen people win international robotic competition with robot made using ...
Albert H M's user avatar
2 votes

Low power to motors -- motor power jumper issue

I had the same problem with the "Ultimate 4tronix Initio 4WD Robot Kit" - the motors make some noise, but do not start moving. I tried using 8 batteries instead of 6 (for higher voltage on the motor), ...
user14084's user avatar
2 votes

it's worth to make a line follower using a raspberry pi and a web cam?

I did a project based on RPi2 + Pi-Camera + ROS jade + OpenCV to make a line following rover. Two methods are used, one is to find contour of the track, the other is to use Hough-transform for edge ...
Alex Huang's user avatar
2 votes

Best power solution for my robot

Regarding the battery requirements, LiPo batteries are probably the way to go, but they do require looking after in order to prevent any nasty accidents from occurring. I looked into this a few months ...
Greenonline's user avatar
  • 1,459
2 votes
Accepted

Quadcopter PID Control: Is it possible to stabilize a quadcopter considering only angle measurements?

It is possible to stabilize a quadcopter using only angle measurements in a single loop pid. However it is easier to stabilize a quadcopter using a cascaded PID controller. Yes you are tuning more ...
user123456098's user avatar
2 votes
Accepted

Quadcopter PID Controller: Derivative on Measurement / Removing the Derivative Kick

All PID controllers act on an error signal, so you definitely should stick with your first implementation. The derivative term in the PID controller wants to "see" how the error is changing - if the ...
Chuck's user avatar
  • 16k
2 votes

Can ROS run on a Raspberry Pi?

Yes. Sure. We've been doing this long time. ROS is not an "OS" and it's not big. It's just "middleware" which runs well in "Raspbian". We just burn with the official ...
Nick Qian's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible