Skip to main content

Featured Post

Product Design of a 4 wheel differential drive robot

Getting started with GPIO (Testing GPIO with a multimeter)

There are 65 possible GPIO pins that you can control. Some of the GPIO pins are normally configured to different functions. Let's play with one of them.

Go to the beaglebone website and figure out the header pin corresponding to gpio23.

The gpio23 is mapped to the 13th header pin. In this tutorial we are testing the gpio23 output using a multimeter (Do not connect an LED directly to BBB IO pin).

First go to following directory

cd /sys/class/gpio/

Then make gpio23 available

echo 23 > export

A new directory will be created. Open gpio directory.

cd gpio23

The direction of IO will be normally set as in (input).  To make it as output,

echo out > direction

Then set the pin to high using

echo 1 > value

Measure the voltage at pin 13 of P8 header. If its 3.3 V then you are on the right track. Pin 1 and 2 will be ground. You can connect the negative terminal of multimeter to pin 1 or 2.

To set output as zero,

echo 0 > value

After finished with the tutorial unexport the gpio23 pin.

cd ..
echo 23 > unexport

To get a better idea refer this site.


Popular posts from this blog

Plymouth theme for Ubuntu

Bored of having the same boot animation screen again and again? There are plenty of Plymouth themes available out there. This is a theme I created by slicing some cool gif files I found online. You can download the theme and find the installation steps on my github account. ( )  The theme is created for Ubuntu 16.04. But this can be installed on previous versions with slight modification. If you have a slow computer then you can watch the whole animation loops. (The VM I used to record the screen was fast though. :))

Remote access your BeagleBone Black using vnc

Before going into how to share desktop with your BBB I assume you have a proper ssh access to your BBB. (through USB) (if not read this ) Also this tutorial is for BBB with Debian installed (type cat /etc/*-release to know which distro you are currently using. Or refer here ) First install the vnc server in BBB.(After logging into BBB) ssh root@ apt-get install x11vnc Then go to your local computer and open a terminal window. Install a vnc viewer like vinagre. sudo apt-get install vinagre Now its time to start vnc server in BBB. x11vnc -auth /var/run/lightdm/root/:0 -forever This will start a vnc server at port 5900. Note this server setup is temporary. If you want to remotely connect to your BBB after a reboot type the above command again. Go to your local computer and type  vinagre A remote desktop will be shown if all goes well. Try exploring other options in x11vnc using (in BBB) man x11vnc The se

Product Design of a 4 wheel differential drive robot

I have been thinking of creating a small mobile robot from scratch. From scratch means, go through all the steps of a product development. Design the overall architecture, design the circuits, make 3D model of the parts, 3D print the parts and finally integrate with ROS. The methods I followed may not be the best practice. The only aim is to reach from idea to actual product (prototype). Features: 4 Wheel Differential Drive Camera WiFi IMU GPS(optional) Overview A 4 wheeled differential mobile robot with wheel encoders, camera, WiFi, IMU and GPS(optional). The first thing I did was to come up with an overall architecture. Raspberry pi 3 will be the heart of the robot. Pi Zero was considered in the beginning, but eventually had to  change because of the lack of support for ROS. Even though able to compile ROS from scratch, it became so hard to compile other packages needed for the project. Since I do not want to use pi to directly control motors, I had to design a