Monday, July 30, 2012


Connecting the RS-232 Camera                               


I bought a LinkSprite LS-Y201 serial port camera module off of the web a few weeks ago. Careful, LinkSprite sells two serial cameras; this one has the max232 chip and is ready to connect directly to the computer’s serial port. My understanding is that the one without the UART chip uses TTL level voltages to connect directly to micro-controllers. Most of the discussion on the web is by robot enthusiasts, using the micro-controller interfaceable camera. There is documentation and a demo program available for this camera, but as I found out later, the info can be confusing and the program worked intermittently for me.


Some of the problem may be the translation from Chinese. Searching the web I found that others have had similar problems. Through trial and error, I have mostly figured this camera out and now have a working demo program written in VB6.

The Camera module fits nicely into a 2” x 2.5” x .75” project box with holes drilled for the lens and cable. The cable connector is in the down direction of the camera field. Inside the box, there was room for a couple of illuminating LEDs with current limiting resistors, wired to the 5v supply. The camera can view images in infrared light but I found out that LCD images (like the numerals on the smart meter face) are invisible in infrared light! I mounted the camera in front of the smart meter and connected it to the four wire telephone line leading back to the RS-232 port connector. Make sure the camera’s TXD is connected to the computer’s RXD (and TXD to RXD). For the 5vdc connection, I used the computer’s power supply through an inline 0.75 amp fuse. I blew the fuse several times during the installation of the camera. If you do not use a fuse, you are going to ruin your computer.

When the camera is powered up you should see the “ Init end” message when Comm1 is viewed by Hyperterminal. 

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