 |
 |
 |
Click on image to enlarge |
I'm doing some autonomous robotics experiments. For this, I use the uCsimm platform.
uCsimm is a computer as large as a simm module. It is based on the Motorola Dragonball CPU, and is equipped with 2Mb FlashROM and 8 Mb RAM. The module has rs232 and ethernet on-board, and is suited to run a scaled down version of Linux: uClinux.
On the leftmost picture, you see the uCsimm sitting in its simm socket. On the motherboard, there is a rs232 connector, ethernet connector, power stabilizer and a reset switch. The red connector is an RJ45 ethernet connector. To the right of it, you see a MiniSSC servo controller from Scott Edwards Electronics. It drives the servo that you can just barely see in the background. The nice thing about the servo controller is its incredibly simple interface: just send it commands over a serial line. The commands consist of 3 bytes: a 1 byte header, a servo number, and a position value.
This set of miniature electronics is now controlling my very own mobile autonomous robot.
|
Brains uCsimm, MC68EZ328 at 14.3MHz, 1.79 bogomips, 2MB ram, 8MB flash rom |
|
Operating System uClinux, kernel version 2.4.x |
|
I/O 10mbit ethernet, rs232 console, rs232 8 channel servo controller |
|
Locomotion Differential steering using 2 servos modified for continuous rotation. Each wheel can be controlled by setting speed and direction. The wheels are fitted with odometers which are based on Hamamatsu photoreflectors. My webcam picked up the invisable light from the transmitter as can be seen in the image. |
|
Sensors Two transmitter/receiver pairs for ultrasonic waves. These sensors are mounted on a 2-DOF tilt-swivel turret. |
|
Development Applications are cross-developed using a x86 linux host. The robot accesses the application binaries via NFS, so that development can be done without burning flash. For development, GNU's g++ compiler is used. |
|
Weaponry This robot is defenseless thus harmless, and it is a firm believer in non-violence. Also, it is an activist against the shameless slaughtering of robots on robot-wars and similar events. |
|
Chassis Aluminium with plexiglas shell. |
|
Power 8.4V 940 mAh NiCd for servo controller, fischertechnik accu (usage: 12mA) 4.8V 2400 mAh NiCd for servo motors (usage: 12 mA per idle servo) 4.8V 2400 mAh NiCd for uCsimm (usage: 110 mA max) Overall battery capacities are larger than required, all battery charges will last at least 24 hours. |
|
Output The robot lacks its own LCD screen, so all output is sent via ethernet, but the robot also has its speech synthesizer using a SP0256 processor. This processor is able to generate speech using phonemes, giving it an unlimited vocabulary, and makes it sound more like a dalek than a simply recorded sound fragment. |
|
Vision This robot competes in the c't robot wettbewerb. For this, the robot is controlled by my vaio notebook, which does the image processing. |
|
- - |
