This open source project is driven from a thingiverse project - turtlebot to build an inexpensive WiFi quadruped robot . The quadruped robot it is controlled via WiFi by any devices (iphone,android phones,tablet,iPads and computers) with web browser. So it is much more fun to make and play. WiFi Turtlebot uses cheap commodity components which people can easily find and buy them in the market.
WiFi Turtlebot in Actions - Video Demo
What you need to build it?
|3D Prints the Body. Get the models and print them.|
|1G SD Card, download SD image for model b and model b+. |
The program controls the robot auto run while RPi booting the SD.
|8 x 9g Servos|
|12 of M3 bolts and nuts|
|Power source - power bank|
|WIFI Connection - USB WiFi Dongle|
e.g Ralink RT5370 USB Wireless Adapter
The RPi P1 header GPIO pins are used to connect 8 servos. The pin assignment is as following. There are 2 servos for each leg. The one is close to the body is named thigh and the one is far end named leg for describing in connection to the GPIO pins.
Servo number Pin in P1 header s1 P1-7 s2 P1-11 s3 P1-12 s4 P1-13 s5 P1-15 s6 P1-16 s7 P1-18 s8 P1-22 Facing to the turtlebot, +-00-+ left / \ right s1 - right_front_thigh s2 - right_front_leg s3 - right_back_thigh s4 - right_back_leg s5 - left_back_thigh s6 - left_back_leg s7 - left_front_thigh s8 - left_front_leg
The servos should be calibrated to following degrees as the initial positions (stand).
s1_right_front_thigh_center 117° s2_right_front_leg_center 36° s3_right_back_thigh_center 54° s4_right_back_leg_center 117° s5_left_back_thigh_center 117° s6_left_back_leg_center 36° s7_left_front_thigh_center 54° s8_left_front_leg_center 117°
How to play?Turn on RPi, when WIFI is ready, it will boardcast SSID - turtlebot-color, join the WiFi with password 12345 then open a web browser, access http://192.168.3.1:9000/, you should see a control page as below.
Press the buttons to trigger the actions
DevelopmentThis project is open source. Source code is hosting https://bitbucket.org/vmmgrs/wifi-turtlebot/. People are welcome to improve the program. Currently the implementation of kinematics is not good enough, see if someone can solve the inverse kinematics. It is good exercise of kinematics, anyway.
One More Thing...
The internal OS of WiFi turtlebot is OpenWrt. OpenWrt user friendly web admin page (see below figure) can be access by the URL http://192.168.1.1/ on LAN port or http://192.168.3.1/ on WiFi. You can change WiFi authentication or system setting by it. OpenWrt Wiki provides documentations. A beginner should read them.