UM0068 Datasheet, PDF (11/17 Pages) STMicroelectronics – USB low-speed evaluation board

UM0068
Running the USB low speed evaluation board
2.2
2.2.1
HID demonstrator
USB enumeration
The device selection tabsheet, shown in Figure 4, displays the following information:
● Available USB HID devices: All the HID devices connected to the PC are displayed in
this window.
● Device information
This information, obtained during the enumeration phase, refers to the highlighted
device in the “Available USB HID device” window: vendor ID, product ID and version
numbers (refer to the USB Specification version 1.1 or higher). In addition, as string
information is supported, the manufacturer name, product and serial number are
displayed.
Figure 4. HID demonstrator window
HID attached
device
Device
information
2.2.2
Communication with the evaluation board
Controlling the evaluation board from a host PC
The HID demonstration tabsheet, shown in Figure 5, displays the following information:
● Click on the ON/OFF button in the application dialog box to switch on the LED LD2 on
the board.
● Click again to switch it OFF.
● The slider bar controls the brightness of a LED LD3 (ST7262xxx) or LD1 (ST7263Bxx).
Each slider bar value will be converted to a pulse width modulation (PWM) signal by the
microcontroller.
Displaying the evaluation board state
● Button state: this red LED changes its state when you press the SW1 push button on
the evaluation board.
● Trimmer value: this value is the result of the analog-to-digital conversion of the RV1
trimmer output. When you turn the trimmer on the evaluation board to a different
position, the new ADC value is transmitted via the USB bus and displayed on the
progress bar of the HID demonstrator.
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