Texas Instruments TUSS44 0 Series, Руководство пользователя

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15 SLAU822A – December 2019 – Revised April 2020
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TUSS44x0 EVM for Ultrasonic Sensors User's Guide
Driver — The driving frequency, pulse count, and driving current limit are set with this group. This group
is specific to the generation and transmission of an ultrasonic echo. The frequency of a single
transducer is fixed, but the drive strength can be reduced or increased using the number of pulses
and current limit.
Receiver — The gain selected on the block diagram view enables or disables various stages of the log
amplifier. This group is specific to amplifying the raw ultrasonic echo received. A small gain is
favorable for short range measurements to prevent saturation of the returning ultrasonic signal. A
large gain is favorable for long-range measurements. The bandpass filter bandwidth is able to filter
the raw amplified ultrasonic echo received from the AFE to create an analog echo envelope output
at the VOUT pin.
3.5.2 Data Monitor
The Data Monitor page displays the ultrasonic echo data dump and the ultrasonic measurement results.
Additional controls including bit field manipulation, data export, parameter sweeps, and external
synchronized triggering is offered on this page.
3.5.2.1 Run Options
Use the Run Options panel to configure the time-of-flight settings and execute a time-of-flight command to
update the chart and table results.
Figure 12. Data Monitor - Run Options
These settings are defined as follows:
START — I nitiates a time-of-flight command to update the Data Dump chart, Measurement & Diagnostic
chart, and Tabulated Results. Applies the updated run option changes before executing the time-of-
flight command. The command is executed using the SPI or GPIO interface channel designated by
the selected IO Mode.
Adv — The Advanced Bit Field Controls (Adv) view control either hides (unchecked) or shows (checked)
the Adv panel from the Data Monitor page. When visible, the REG_USER bit field values are
updated on the Adv panel after every time-of-flight command.
Loops — The number of loops determines how many time-of-flight commands are automatically issued to
the TUSS44x0 device by the GUI. To run an indefinite number of loops, set the value to 0.
Count — A counter to indicate how many time-of-flight commands have been executed in the given loop
range.
Loop Delay — This field determines how much delay in milliseconds is added between each loop
command.
Start Delay — This field determines how much delay in milliseconds is added before the first time-of-flight
command is executed.
Sweep — Enables minimum to maximum parameter value sweep of each checked field in the Advanced
Bitfield View panel. After the sweep is complete, the pre-sweep values are set.
IO Mode Select — Determines if IO Mode 0, 1, 2, or 3 will be used to generate a burst.