Download Schematic and PCB description for the WSN Imager Development

Agilent Technologies
Rev 0.9
May 12, 2004
Schematic and PCB description for the WSN Imager Development board
The ADCM-1670 imager has many features appropriate for WSN’s. It has a
serial port with flow control, it has JPEG and a frame buffer, and it can be powered
on/off via an I/O. Many customers will find it acceptable for development and first
exploratory products and this board is designed to help them develop those applications
(algorithms) and hardware.
The board may be used in a variety of ways. It is designed to plug directly into
the RS-232 serial port of a laptop or palmtop. The laptop can be used for Matlab or Clanguage algorithm development and extensive processing in a powerful and convenient
environment can be performed. A palmtop can be used if portability is needed – for
some palmtops, the same C language program can run on the palmtop. The palmtop can
display the image and it’s computational results. Application development while
installed on a PC is one of the most important applications for the development board – it
enables WSN imager application development today. A Visual Basic application is
available which can log it’s communications to the imager – then this log file provides
the basis for much more compact programs that simply initialize the imager with the log
file contents. The configuration is shown in Fig. 1.
Level Shifter
Development Board
Computer
Figure 1 – Agilent’s WSN Imager development board connected to a PC’s serial port.
Alternatively, the Agilent WSN image development board may be configured to transmit
the computational results via a radio link. In this case, the computer’s program and the
radio’s program are modified to form a ring serial architecture, shown in Figure 2.
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Level Shifter
Development Board
R -> Radio
C -> Camera
Radio + uP
Computer
Figure 2. The serial ring allows a computer (i.e. Palmtop) with one serial port to
communicate with the radio and the imager.
To execute the structure, the radio’s uP, camera and computer must be at the same baud
rate, and the firmware in the radio + uP must strip off the first character depending on
whether the packet is targeted at the imager or the radio, and the software in the computer
must prefix the packets with this character depending on destination.
For either configuration (Figure 1 or Figure 2), the provided Visual Basic program can
set the imagers registers with a convenient GUI. The interface is shown below.
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In the final case, after the imaging application is worked out on the PC or palmtop, the
application is downloaded to the Radio + uP and run directly there, see Figure 3:
Level Shifter
Development Board
Radio + uP
Figure 3: Prototyping the imager configuration using the uP which is in the radio (or
another outboard uP) for WSN imagers. This is the last stage before production, when
the imager’s connector is mounted directly on the Radio + uP board.
Power is obtained either from a wall wart, or from the radio circuits. Only the DB-9 for
convenient connection to the computer is provided as a fixed format connector – point-topoint wiring is most convenient for other connections between the Radio + uP and the
development board. The imager’s “ON” I/O as well as the I/O enable control of the
imager (for tri-stating the serial outputs, in case a development system needs access to the
uP serial port) are all convenient.
The Schematic is shown below. Two copies of the circuit are shown as the PCB vendor
has a fixed minimum size PCB and we’ll saw the board in half when we get it. A 20
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MHz clock is provided, as well as a voltage regulator (for the wall wart – the 1670
already has a voltage regulator in it for operation down to 2.65V). The size of the board
is approximately 1.5” x 2.5”.
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