I will document my journey to build a wifi controlled Raspberry Pi robot here. This post will be updated as and when I have progress on the project.
- controllable via wifi
- Web interface to control the robot.
- movable using 4 wheels
- has a display (16×2 LCD display is sufficient)
- has a webcam for live feed
- webcam can be rotated for capture at different angles
- run on battery
Nice to have features:
- Mobile interface to control the robot
- a speaker for robot to “talk” (text sent via the website command, then robot speaks using TTS ?)
- a microphone for interaction with human (other people speaks to the robot, and I can hear back at the website command?)
- object tracking: robot is able to track moving objects and follows that object
- Raspberry Pi, Model B
- Wifi dongle
- 16×2 LCD display – USD $5
- PCB boards
- 4 wheels DC motors – USD $16
- USB webcam / Piwebcam
- Servo motor – USD $5.15
- Dupont cables
- PCB boards
- Solid core cable – US $2.95
- Raspberry Pi GPIO Cobbler extension – USD $8
- Pin header – USD $1.5
- Breadboard power supply – USD $1.5
I am in need of a suitable battery pack to power my Raspberry Pi and all its peripherals. This entry is to list down any considerations made along the way :
Remember RaspPi runs at 5V, hence input power is required to provide a steady 5V stream, more and you may destroy the Pi, less and the Pi will start to behave wildly.
A Raspberry Pi needs 5V with 700 mA, meaning it has a consumption of 3.5 Watt.
Note that consumption indicates a maximum value because it can never get more power that the indicated consumption.
(1) Buy an off-the-shelf power bank. A useful article to decide on which power bank to buy : FB don’t buy power bank until you read this
(2) Use AA batteries with UBEC-Universal Battery Eliminator Circuit, which essentially is a switch mode voltage regulator .
I used Motion as the camera live streamer. Found a great short and comprehensive guide for the setup here.
To keep long story short, these are the important commands:
sudo apt-get install motion
sudo nano /etc/motion/motion.conf
=> in the config file, change these values :
Daemon = OFF to ON
webcam_localhost = ON to OFF
minimum_motion_frames 5 to 2999
(changing minimum_motion_frames to avoid Motion to capture exessive screenshots whenever movement is detected. I only need the live stream camera function.
Btw, your screen captures are stored in /tmp/motion )
sudo nano /etc/default/motion
Then change the value “start_motion_daemon=no” to “yes”
sudo service motion start
- Access at : http://[pi ip address]:8081
I accessed ok using Firefox. Chromes doesnot work for some reason.
pi@raspberrypi ~ $ cat /etc/network/interfaces
iface lo inet loopback
iface wlan0 inet manual
iface default inet static
#iface eth0 inet static
# Your static IP
Taken from here
1. Use WirelessKeyView by NirSoft.
2. Use the built-in Windows “netsh” command.
From an administrator command line, type:
netsh wlan export profile key=clear
and then press Enter.
Found this fantastic, brilliant Chrome add-on :
Hola Better Internet
You can also find extensions for other platforms, on its main site : Hola.org
Using Hulu to watch South Park in Chrome currently. Enjoy !
This is an article written by Oracle, hosted here
I face this issue in my work and this guide came to the rescue.
As part of my job, I frequently need to remote into UAT servers, hosted on a secured network, via a Java web interface. Things have been working well until the latest update of JRE to version 7 update 51. Since then, I have been always prompted with an error saying “Missing Application-Name manifest attribute for:” and the connection cannot be established.
From this Oracle article I realize the error is because the aforementioned web program is Self signed. No hush, this is an Intranet program and provided by my trusted partner so I am willing to run this program, and accept its “risk”.
Now, what I need to do is adding the URL into an Exception Site List so Java doesn’t strictly block anything coming from this site.
Here is the guide, copy here for reference :
It is highly recommended not to run these kind of applications, however if you still want to run, run only if you understand risk and implications involved.
As a workaround, the user can use Exception Site list feature to run the applications blocked by security settings. By adding the URL of the blocked application to the Exception Site list allows it to run with some warnings.
Steps to Add URL to the Exception Site list:
- Go to the Java Control Panel (On Windows Click Start and then Configure Java)
- Click on the Security tab
- Click on the Edit Site List button
- Click the Add in the Exception Site List window
- Add url to Exception Site list
Click in the empty field under Location field to enter the URL
( URL should begin with http:// or https://)
If the URL where the applet is hosted is different than the URL for the page on which the applet is called you need to add both the URL for the applet.
Example: For Yahoo games Checkers (This is just an example the host url can be different for depending on which host is serving the game), enter:
http://www.games.yahoo.com and (This is the url for Yahoo games domain)
http://yog36.games.sp2.yahoo.com (This is the url where game is the hosted and is shown in the dialog box for blocked application)
- Click OK to save the URL that you entered.
- Click Continue on the Security Warning dialog