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group3:group3weekly 2008/11/08 17:22 group3:group3weekly 2008/11/24 11:34 current
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Next week, we plan to send and receive a text signal using HyperTerminal between two computers using our free space optics to send the data by laser. Also, preliminary programming will be done in C to control the serial ports of the sending and receiving laptops. Next week, we plan to send and receive a text signal using HyperTerminal between two computers using our free space optics to send the data by laser. Also, preliminary programming will be done in C to control the serial ports of the sending and receiving laptops.
 +
 +== Week 11: November 10-14 ==
 +
 +The sending end of the circuit was modified such that it would send a 0 as a high voltage, and a 1 as a low voltage, opposite of intuitive. The advantage this inversion is that the laser will be on when no data is being sent, making alignment with the telescope end more possible.
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 +Freeware software called "Realterm" was obtained from Sourceforge.com for sending data and files by serial port without any protocol (handshaking that would require sending back and forth).
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 +On Friday, the FSO system successfully transmitted a 500kb picture from across the lab at a 38400 baud rate in under 5 minutes. Higher baud rates were tested with text and pictures, and found to work up to a standard baud rate of 57600. Non-standard baud rates can be chosen in Realterm, though 57600 or 38400 is sufficient for our project, and most likely safer.
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 +The rest of the work on the project will work on moving the project outdoors. The challenges ahead are mounting methods for the telescope and laser, as well as power solutions for our project (since power supplies are used currently).
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 +
 +**Nov 24**
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 +In the last week, the group was experimenting with USB powering for their circuit. A Max 232 chip with capacitative voltage increasing was used to go from 5 to 9V. A second laser pointer and a NAND gate(which is part of the MAX 232 chip) were also implemented. The addition of the chip has not yet been sucessfully tested.

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