First let me say that I don't claim to
know allot about electronics or programing. If not for the help of
two friends on the Bascom Forum I would not be writing this page.
I have been a recreational scuba diver
for about 20 years. For as long as I can remember I have wanted a
ROV. A remotely operated vehicle to go underwater. I have been a
machinist for 13 years also. So with that background I figured I
would try to build a ROV since to buy one is out of the question. I
have seen that other people on the web are making them so I figured I
would give it a shot. Another one of my interests is surveillance
cameras & security. Earlier I acquired two American Dynamics
Speed Dome PTZ cameras. They use the Hitachi VK series compact
chassis camera. I knew the capability of the camera block and thought
that would be perfect for the ROV. I knew the VK series cameras can
be controlled using RS-232c. So I started searching the web for
information on how to control them. I had found out that the person
that helped me first get the PTZ cameras working had controlled a
VK-S274R with a PIC. He kindly sent me the command codes for the
camera. I didn't want to use a laptop or PC to control the ROV. So
knowing that it could be done with a micro-controller I started
learning about PICs. To make a long story short I was convinced to
use an AVR by a friend (not at the time) and he offered to write the
program for me. After some e-mails back and forth I purchased the
Futurlec Atmega8535 controller.
This is the Futurlec Controller board I
use. It is fairly inexpensive. The back bone of this board is the
Atmel Atmega8535. The board has up to 28 I/O ports, RS-232 connection
with the Max232 chip. The Atmega8535 can be programed while on the
board (in-circuit programing). The board even includes the programer.
However it requires a 25 pin parallel port.
The Hitachi VK series cameras all have
a 9 pin Flat Flex Connector. You will need to come up with a way to
interface the power, video & serial communications to the camera. The pinout is as follows.
On the first camera I carefully removed the 9
pin connector and soldered a 5 conductor ribbon cable to the pads on the board. The other end went to a DB-9 connector. The mating DB-9 connector had the power, video & serial plugs soldered to the appropriate pin. Ground is common.
Later I made a board that mounts to the back of the camera. I use the existing screw holes on the camera to mount it. The blue connector is for power. The connector above the power connector is a BNC for video. The round black part above the DB9 is a bridge rectifier. I put the rectifier in so you can't hook up the power backwards. Pin 3 on the DB9 connector goes to the RX of the camera. Pin 2 goes to TX and Pin 5 is Ground. The camera is able to echo back the settings of the camera if the program is written to do so. You can download the Autocad2000 file of the board. The file is VKBoard.dwg. It includes the Part numbers for all 5 components on the board. The flat cable came from an old copy machine. I don't know where to get them. It will have to have the contacts on opposite sides of the cable to work. You can get a flat cable with the contacts on both sides from Time Lapse Supply.
If you want to save time and hassle you
can buy an interface board from Vision Reality. They are available for $30.00 that also includes shipping. They will work for the Hitachi VK series,
Sony FCB-EX series and some of the LG camera modules. These are very
nice boards made with all new parts. They come with a serial cable,
power cable and a flat flex cable.
The board has connectors for the
serial, power & video out. Making it easy to connect and
disconnect the camera module. There is a Max232 IC to convert the
RS232C to RS232. If you need test software that is available on the Downloads Page.This is the easiest way I know to connect your camera for
testing or use in your project. I didn't know about these boards
until after I made my own. It would have saved me a lot of time and