Wireless Security Camera

Transcription

1 Wireless Security Camera Technical Manual 12/14/2001

2 Table of Contents Page 1.Overview 3 2. Camera Side 4 1.Camera 5 2. Motion Sensor 5 3. PIC 5 4. Transmitter 5 5. Power 6 3. Computer Side 7 1.Receiver 7 2.Computer 7 4. Troubleshooting 8 2

3 1. Overview The wireless security camera capable of communicating through radio frequency (RF) transceivers to a small portable laptop computer. The detection device will contains a small black and white camera and a motion sensor capable of sensing movement in the cameras viewing range. The camera and sensor will be connected to a small microprocessor that will converts the camera's digital signal and the sensor data into a signal capable of being transported through the RF transceiver to the laptop computer. There is a second RF transceiver connected to the laptop by a parallel port connection. This connection will allows the security camera to work with any computer. A software program will be loaded onto the laptop computer that will receive the information from the camera and sensor and display the current image and sensor data on the screen. 3

4 2. Camera Side The camera side is the part that contains the camera and motion detector. The schematic for the system is as follows. 1-8 D0~D7 Wireless Camera with Transmitter M4088 1/4" B/W Camera With Digital Output A3~A0 9, OEB WEB CSB Slim Line PIR Motion Sensor Laptop Computer with USB Interface, D+, D RB0~RB7 25, 26 TX, RX 16, 14 RXD, TXD PIC16C745 8-bit CMOS Microcontroller with USB PKLR2400S 10 mw RF Tranceiver RD3~RD0 3,5 20, RD5~RD7 12,32 11, RA0~RA1 5 V, 300 ma Regulated Power Supply 12,31 11, Vss Vdd D+ D- PIC16C745 8-bit CMOS Microcontroller with USB 25, 26 TX, RX 16, 14 RXD, TXD PKLR2400S 10 mw RF Tranceiver Receiver 3,5 20,21 4

5 2.1 Camera The CMOS camera is located below the motion detector. The camera itself is 35 x 29 mm. The picture output is black and white with 384 x 288 resolution. The field of view is 57.9 x 45.7 degrees. The voltage required is 5 volts regulated. Pin Description 1-8 Bi-directional Data Bus 9 5 Volts +/ GND Address input for int registers 15 Output enable for 8 bit data 16 Write enable for int register 17 Chip enable for device 18 Horizontal timing ref output 19 Pixel clock output 20 Vertical timing ref output 2.2 Motion Sensor The motion sensor is a passive inferred detector that uses radiation given off by the body to see if any thing is moving. There are three wires that go to the detector from the main board. The red wire is +12 Volts, black is GND, and green is signal. The detector needs 9-16 volts to operate. When motion is detected the green wire sends a signal to PIC to send what ever the camera is seeing at the time to the transmitter. 2.3 PIC The PIC acts as a buffer between the camera and the transmitter. Since the camera sends out data in 8 bit increments a buffer is needed to output the data in serial for the transmitter. Once the PIC received the pulse from the detector, the PIC will then output whatever is at port A to port B incrementally. 2.4 Transmitter The transmitter then receives serial input from the PIC and sends it at 2.4 GHz to the receiver on the other side. 5

6 2.5 Power The power is brought into the device by a 12-volt power supply. This provides power for the motion detector directly. 5-volts is provided for the camera, transmitter, and PIC by using a voltage divider circuit with a total resistance of 26 ohms. D2 D3 380 Sensor 12Vdc V1 D1 Oscilator PIC Camera Transmiter 6

7 3. Computer Side 3.1 Receiver 3.2 PIC The receiver then outputs the signal to the PIC on the computer side. The PIC on the computer side then acts as a buffer in the opposite way as the camera side. Data is brought in on port B and stored until 8 bits are received. Then those stored bits are moved over to port A and moved along to the computer though the parallel port. 3.3 Computer The signal is then brought to the computer via parallel port. CameraView then opens the picture and displays it on the screen. 7

8 4. Troubleshooting Motion detector is not detecting motion. 1. Make sure the detector is plugged in and has 9-12 volts. 2. Does the LED turn on in the detector when there is movement? 3. Yes, problem fixed. No, send it back in. Computer is not receiving picture. 1. Move camera closer to the computer. 2. Did this fix the problem? 3. If yes then camera was out of range. 4. If no then unplug USB and reattach. Picture is upside down. 1. Turn the camera so that the motion sensor is above the camera. Image is too dark. 1. This camera requires 1 Lux of light to operate. Image is too bright. 1. Turn down lights in the room or move camera away from light source. 8