Linx Technologies MDEV-USB-QS - Manual (Page 5)

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The RS-232 Area
The RS-232 area contains an RS-232 level converter that works with the
QS Series module to create a USB-to-RS-232 converter. All of the modem
lines are provided to allow for full handshaking, and power is provided
by the USB bus. To use, plug the USB cable from the PC into the jack, a
straight-through serial cable from the PC into the DB9 connector and place
the jumper in the breakout header between “Data In” and “Data 232”.
The development software is designed so that testing can be done with
a single PC by sending data through the USB bus and receiving it back
through the serial port and vice versa. This section can also be used to
interface the PC with any RS-232 device. Custom software can be written
to control the device directly, or the Virtual COM Port drivers can be used
to make the USB module look like a serial port so that existing software
can be used.
Figure 6: The RS-232 Section
The Microcontroller Area
The microcontroller area contains a PIC microcontroller from Microchip and
demonstrates how to interface the QS Module with a processor. Figure 7
shows the Microcontroller area on the development board and Figure 8
shows the Send and Receive via USB section in the development software.
The software sends data to the microcontroller to turn on LEDs when the
user clicks the LED1, LED2 or LED3 buttons on the computer screen. The
microcontroller sends data to the PC to light up the USB COM indicator
on the screen when the USB COM button on the board is pressed. The
microcontroller also sends data to control the A / D Voltage Adjust slider
when the Voltage Adjust knob on the board is turned. Source code
examples are provided with the software documentation to demonstrate
the simplicity of interfacing the QS module with a processor and to aid in
product development.
The USB bus provides all of the power for this section. To use, plug a
USB cable into the jack and the PC, place the jumper in the breakout
header between “Data In” and “Data PIC”, and run the application software
included with the kit.
Figure 7: The Microcontroller Section
Figure 8: The Software Send and Receive via USB Section