OmniPreSense 242A User Manual

OPS-UM-001-C User Manual OmniPreSense Corporation 1

OPS242 User Manual

OmniPreSense OPS242 short range radar sensor has an easy to use API to control the output of the sensor.
Simple commands can be used to configure the operation and output information provided by the sensor.
Default settings are noted below. Upon powering on the module, the default settings are used.

Installation Instructions

The OPS242 provides a complete radar module on a single board. The coverage area or field of view (FOV)
for the OPS242 is 76 in the azimuth (horizontal) and elevation (vertical). Install the OPS242 facing the
direction of the FOV to be covered.

Figure 1. OPS242 Beamwidth

The OPS242 can generally can be placed behind most any material (plastic, glass, wood, etc.) depending
on thickness. Typical applications will use plastics such as ABS or PVC at 3 or 6mm thickness. Some
materials will block the signal and the OPS242 should not be placed behind these. Examples of these are
metal, concrete or brick.

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Terminal Control

A simple Command Terminal can be used to control the sensor operation with the API commands.
Examples of simple but very useful Command Terminals are Tera Terminal and PuTTY. Both are free, open
source terminal tools for the PC/Mac which can easily connect to a serial port and accept data over USB
from the OminPreSense sensor.

To begin using the OmniPreSense module, first download Tera Terminal or PuTTY onto your PC/Mac. With
the OmniPreSense sensor plugged into the USB port of your PC/Mac, start Tera Terminal or PuTTY. A
configuration window such as in Figure 2 or Figure 3 will appear. TeraTerm can detect the active COM
port (greyed out to right of Serial button if TCP/IP is selected). Select the Serial button and press OK. For
PuTTY, you’ll need to know which COM port is used, set its value, select the Serial button, and Open.

Figure 2. Tera Term Startup Menu

Figure 3. PuTTY Startup Menu

Once connected, the data reported by the sensor will start streaming to the terminal when an object in
motion appears. The default settings are shown in Table 1. If there is no object moving in front of the
module, no data is reported or streamed to the terminal. A simple wave of the hand will show data like
that shown in Figure 4. Any of the API commands can now be executed to change the output data or
query the configuration.

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Figure 4. Streaming Data with Tera Term

Figure 5. Streaming Data with PuTTY

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Default Settings

The default settings of the sensor are set to provide solid performance over a wide range of applications.
Upon power-up the default settings are used, and operation begins. Future updates will allow the module
to retain the settings of the sensor from the last operation. The default settings are listed in Table 1.

Table 1. Default Settings

API Command

API Command

Default Value

Output Units

UM

m/s

Data Accuracy

F2 2 Sample Rate

SX

10,000

Sample Buffer Size

S>

1024

Reported Speed Filter

R=n

Off

Reported Direction Filter

R|

Off

Quash Noise

QQ

On

JSON Output

Oj

Off

LED Control

OL

On

Magnitude Report

Om

Off

Number Reports

On

1

Raw Data Output

Or

Off

Speed Report

OS

On

Time Report

Ot

Off

Module Power

PA

Active

Operating Range

The maximum speed reported is determined by the Sampling Frequency. For slow moving objects, a
sample rate of 5,000 (SV command) is perfectly fine. The default setting of 10,000 (SX command) provides
a detectable speed of up to 31.1 m/s (69.5 mph) while 20,000 (S2 command) provides up to 62.2 m/s
(139.1 mph). The accuracy of the reported speed increases as the sample frequency goes down. The
range of values is summarized in Table 2.

Table 2. Maximum Operating Speeds

Sample

Frequency

API

Command

Maximum

Speed (m/s)

Maximum

Speed (mph)

Accuracy*

(m/s)

Accuracy*

(mph)

1,000

SI

3.1

7.0

0.006

0.014

5,000

SV

15.5

34.8

0.030

0.068

10,000

SX

31.1

69.5

0.061

0.136

20,000

S2

62.2

139.1

0.121

0.272

50,000

SL

155.4

347.7

0.304

0.679

100,000

SC

310.8

695.4

0.608

1.358

* 1024 buffer size, 512 buffer size accuracy will be twice these values