30 votes
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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 ...
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  • 14.7k
10 votes
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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 ...
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  • 1,825
8 votes
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Can I control more than 18 servo motor with a Raspberry Pi

Raspberry Pi has only one hardware PWM channel and Linux distribution it runs is not a real time system, so software PWM may be very unstable. You are not guaranteed, that your program will be ...
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  • 953
6 votes
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Which micro-controler/processor to be used for autonomous stereo vision robot system?

Stereo vision and SLAM are pretty heavy algorithms, both in terms of the processing power and RAM required. You can forget about running this on a little microcontroller like an Arduino. These run at ...
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  • 6,337
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The ROSBerryPi page is quite outdated, you actually can install prebuilt ROS Groovy binaries on Raspbian.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 ...
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  • 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 ...
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  • 1,647
5 votes
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Build a ROS robot with SLAM without laser

A kinect mounted on your robot is enough for mapping and localization. There are a few different packages that will work: rgbdslam can create a 3d map using a kinect You can use ...
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  • 101
5 votes

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

This may be overkill, but some of the past work I was involved in was trying to detect a vertical line (a pipe) in the camera's field of vision, and navigate relative to it. The process was as ...
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  • 10.8k
5 votes

Raspberry Pi for two wheel robot?

A Raspberry Pi should be sufficient for the control you intend to do with it. In designing a controller under a full multitasking operating system, like the Linux operating systems that are available ...
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5 votes
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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 ...
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  • 14.7k
5 votes
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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. ...
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  • 321
5 votes
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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
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5 votes
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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 ...
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5 votes
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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: ...
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  • 295
4 votes

Can I control more than 18 servo motor with a Raspberry Pi

You need a controller like this that can address them individually over I2C. These can be chained together to control more than you'll likely ever need: Adafruit 16-Channel 12-bit PWM/Servo Driver - ...
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4 votes
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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 (...
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  • 510
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 ...
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  • 953
4 votes
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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 - ...
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4 votes
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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 ...
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  • 451
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 ...
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3 votes
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Sensing the level of a liquid in a tube

If you look in the industry, they usually use capacitive proximity sensors. This sensors can be adjusted easily to sense behind the glass. In addition I can tell you, that this measurement is highly ...
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  • 1,647
3 votes
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What is required to build a simple XY-stage?

Simple X-Y stages are well understood and form the basis for the many open source hardware projects for 3D printers. Each axis of an XY stage can be made from a pair of 6mm stainless steel rods, ...
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  • 4,098
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. ...
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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 ...
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  • 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 ...
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  • 155
3 votes
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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. ...
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  • 952
3 votes
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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 ...
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  • 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 ...
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  • 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 ...
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  • 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 ...
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  • 295

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