Filed Under: Hardware
Parts list:
So, how is OVR working?
Let’s start with the basics. How the hell do we power all these components? The router is powered from the original power adapter, so we need a plug. In the near future, we want to power it from 6 NiMh cells, using a switching power supply (the voltage needs to be very near 5 V all the time). The webcam is powered by the USB port of the router. Everything else is powered by the 4 rechargeable batteries. The servos and the motors are connected directly, electronic components are connected trough the voltage regulator and some filtering capacitors.
Now, how are commands sent? The router runs the OpenWRT Linux distribution and the WiFi card is enabled. There are two daemons running on it: spcaserv for streaming the video from the webcam, and our program (written in C), used for remote controlling. The router gets the commands via a TCP socket. How the hell can it move the motors? Well, that’s the microcontroller’s job. The microcontroller runs a program written by me in BASCOM AVR and it receives the commands from the router using the serial port. It generates a PWM signal for the servos, and uses the FAN drivers for the electric motors moving the tracks and for the LEDs mounted on the webcam.
What do we use the servos for? One AS-170 moves the webcam (and the LED’s) up and down. SG-5010 moves the lower part of the arm. Another AS-170 creates an articulation at the middle of the arm. The last AS-170 is used for grabbing stuff.
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Parts list:
Asus WL-500GP router
Atmel Atmega48 microcontrolle
3x FAN 8082 electric motor drivers
LM2940T voltage regulator
1x SG-5010 servos
3x AS-170 servos (Don’t buy them, they more or less self distruct if the arm somehow gets stuck!)
4x Sanyo 2500mAh NiMh rechargeable batteries
Phillips SPC200NC webcam
Tamiya Track and Wheel set
2x Tamiya Double gearbox
5x white LEDs
Different […]
I wrote the Windows controller, just because the visitors of our stands like better windows than *nix. Since the application’s purpose was just to send plain text over tcp, I used a high leve, basic-like scripting language, AutoIt V3.
First, I should mention some commands the robot knows about:
forward,right,left,back,stop - for movement
ledon,ledoff - for light control
numbers […]
We continued with the robot development after the Jury’s special award in Dreamline International Design Olympiad, and tried to go to other contests. We qualified also to Busef, in Adana,Turkey, but didn’t manage to go, since it was Easter holiday in Romania. But we succeded to qualify to Infomatrix (in Bucharest, Romania), and more than […]
[…] despre Open Video Robot Cosmin a avut bunavointa sa scrie un post despre Open Video Robot, mai in detaliu. Acolo gasiti chestii pe care Baghy nu le-ar intelege, si culmea, nici eu pe […]
June 8th, 2008 at 11:31 pmNice job. Kappacelu sucks
June 9th, 2008 at 12:03 am