This is the software required to build a lego robot with a webcam that streams over HTTP. Full instructions are here on the instructables website The code consists of a pyhton server that can be run on a raspberry pi, and a Javascript client that communicates with the server using PubNub
Current version works with pubnub v4
pip install 'pubnub>=4.1.2'
and any version of python
The channel can be anything, but must match on client and server
| Controller | Description |
|---|---|
| Button | click the buttons to control dogbot |
| Joystick | touch joystick, nice to use on a tablet |
| voice | voice control, speak commands and watch dogbot move |
- Raspberry Pi model B+ (although earlier versions should work)
- Ryanteck RTK-000-001 Motor Controller Board
- Motor Robot Car chassis kit with Speed encoder (bought from Amazon)
- Recharge battery pack for power source
- 4 AA batteries for motor power
- Lots of bits of Lego form my sons lego sets and some from my old lego set
- PubNub realtime infrastructure-as-a-service
- Raspbian Jessie
- Python
- Javascript virtual joystick
- sudo apt-get update
- sudo apt-get install motion
- sudo apt-get install python-dev python-pip
- sudo pip install 'pubnub>=4.1.2'
- git clone https://github.com/petekaras/lego-robot.git into your home directory
| Property | value |
|---|---|
| daemon | on |
| ffmpeg_output_movies | off |
| output_pictures | off |
| stream_maxrate | 30 |
| width | 480 |
| height | 360 |
You can vary the stream_maxrate to increase the quality of the video. Also play around with the width and height settings.
| Property | value |
|---|---|
| start_motion_daemon | yes |
add the following lines to \etc\rc.local
#Robot starts webcam
sudo motion
#Robot listens to commands
nohup sudo python /home/pi/lego-robot/server/robot.py &
Find the name of the device of the plugged in SD-card, by typing:
ls -la /dev/sd*
plug and unplug the USB reader to find out which device to use. Now write the image:
sudo dd if=2016-02-26-raspbian-jessie.img of=/dev/sdb
Might take a while over USB 2.
I used this to connect up to a newly installed Raspian OS, and set up the wifi. Saves having to connect up keyboard, mouse and screen. The wires of the cable should be connected like this:
| Wire color | GPIO |
|---|---|
| red | 5V |
| black | GND |
| white | GIO14 |
| green | GPIO15 |
Install screen
sudo apt-get install screen
Run screen:
bash screen
You should then be prompted to logon to the pi If that doesnt work try:
sudo screen /dev/serial/by-id/usb-Prolific_Technology_Inc._USB-Serial_Controller-if00-port0 115200
##Setup wifi on the commandline
Update the config file /etc/wpa_supplicant/wpa_supplicant.conf with your wifi details:
network={
ssid="Network_name"
psk="Your_wifi_password"
}