UM0313 datasheet(12/33 Pages) STMICROELECTRONICS

12 / 33 page

Graphical User Interface

UM0313

12/33

3.1

Connecting to the Virtual COM port

Before using the functions of the evaluation kit software it is necessary to open the

connection with the EK302DL board. This is achieved through the following procedure:

connect the EK302DL to the desired USB port;

in the “Select COM” drop-down menu (Figure 9 ref 1), choose the Virtual COM number

to which the board has been mapped. For additional information on how to obtain this

number, see section 2.3;

open the connection by clicking on “Connect” (Figure 9 ref 1). When this procedure is

complete, the general purpose LED on the board will switch from red to green.

At this point the user can acquire, plot and save the acceleration data measured by the

sensor and access the content of the registers embedded in the device.

The following sections provide details regarding the functions of the tabs in Figure 9, ref 3.

3.2

“Options” tab

The Options tab allows the user to control the following parameters:

●

Full Scale (FS) - Sets the maximum acceleration value measurable by the device. It is

possible to select either 2g or 8g (Figure 10, ref 1).

●

Data Rate (DR) - In this box the rate at which each acceleration sample is produced

can be selected. The possible values are 100 Hz or 400 Hz (Figure 10, ref 2).

●

Tri-State (TS) - Permits switching the SPI lines of the ST7-USB microcontroller

mounted on the evaluation kit between 3-state (i.e. high-impedance) and normal mode

(Figure 10, ref 3). This function makes it possible to isolate the sensor mounted on the

board from the microprocessor, in case any external control (from a different

microcontroller mounted on a separate user board) is needed.

●

High-Pass Filter (HP) - This control activates the High-Pass Filter on the device and

selects the cut-off frequency (Figure 10, ref 4).

●

Interrupt on Pad IntX - Allows the selection of the type of signal to be sent out on Int1

and Int2 Pad (Figure 10, ref 5).

UM0313 Datasheet(PDF) 12 Page - STMicroelectronics