GSS CozIR-LP3 User manual

CozIR®-LP3 Evaluation Board User Guide
Revision 1.5: 15 December 2020
Page | 1 For regular updates, go to https://gassensing.co.uk
CozIR®-LP3
Evaluation Board
User Guide

CozIR®-LP3 Evaluation Board User Guide
Revision 1.5: 15 December 2020
Page | 2 For regular updates, go to https://gassensing.co.uk
TABLE OF CONTENTS
INTRODUCTION ..............................................................................................................................4
USB DRIVER ....................................................................................................................................5
SOFTWARE INSTALLATION ..............................................................................................................5
INSTALLING THE SENSOR ................................................................................................................5
EVALUATION BOARD CONCEPT.......................................................................................................6
STANDALONE OPERATION ..............................................................................................................8
SENSOR POWER SUPPLY .................................................................................................................9
Method 1 - External Power Supply ..................................................................................................... 9
Method 2 - USB Power Supply............................................................................................................ 9
Method 3 - Variable External Power Supply ..................................................................................... 10
SENSOR POWER CONSUMPTION MEASUREMENT .........................................................................12
ENVIRONMENTAL CONDITION MONITORING................................................................................12
EVALUATION BOARD BUTTONS, JUMPERS AND LED INDICATORS .................................................12
SOFTWARE USER INTERFACE.........................................................................................................13
RUNNING THE SOFTWARE.............................................................................................................14
SENSOR SELECTION.......................................................................................................................15
CO2SENSOR MEASUREMENT MODE .............................................................................................16
UART Communications Mode........................................................................................................... 17
I2C Communications Mode ............................................................................................................... 17
OTHER ENVIRONMENTAL SENSORS...............................................................................................18
GRAPHING SENSOR DATA .............................................................................................................20
ZERO-POINT SETTING THE SENSOR................................................................................................21
ZERO IN NITROGEN ........................................................................................................................... 21
ZERO IN AMBIENT CONDITIONS ....................................................................................................... 21
ZERO IN A KNOWN GAS CONCENTRATION....................................................................................... 22
AUTO-ZERO FUNCTION ..................................................................................................................... 22
AUTO-ZERO INTERVALS.................................................................................................................22
AUTO-ZERO LEVEL............................................................................................................................. 23
PRESSURE COMPENSATION ..........................................................................................................24
DIGITAL FILTER SETTING................................................................................................................25
SENSOR COMMUNICATIONS.........................................................................................................26

CozIR®-LP3 Evaluation Board User Guide
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DATA DISPLAY...............................................................................................................................27
DATALOGGING..............................................................................................................................29
TERMINAL VIEW ...........................................................................................................................31
TERMINAL VIEW – UART READ......................................................................................................32
TERMINAL VIEW – UART WRITE ....................................................................................................33
TERMINAL VIEW – I2C WRITE.........................................................................................................34
TERMINAL VIEW – I2C READ ..........................................................................................................35
MECHANICAL DIAGRAM................................................................................................................37
IMPORTANT NOTICE .....................................................................................................................38
ADDRESS.......................................................................................................................................38
REVISION HISTORY........................................................................................................................39

CozIR®-LP3 Evaluation Board User Guide
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Page | 4 For regular updates, go to https://gassensing.co.uk
INTRODUCTION
This evaluation board is designed to provide a fast and easy start for evaluation of the GSS CozIR®-
LP3 sensor. The evaluation board brings several interfaces and interconnections shown in Figure 1.
The CozIR®-LP3 Evaluation Board is designed to allow the user to evaluate all the hardware and
software functions of the sensor.This manual provides information about the board’s
interconnections, jumper settings, communications, and debug interfaces.
The sensor can be controlled by a PC application via the USB interface, or standalone and controlled
externally via connections to the sensor on the evaluation board.
The sensor and other supporting electronics can be evaluated using a PC software application. This
provides the user with a graphical user interface to all the main functions of the sensor, as well as a
terminal mode, allowing the user to write and read data directly from the sensor registers.
As well as evaluating the CO2sensor, the software application allows the user to monitor and store
other environmental conditions such as pressure, relative humidity and temperature.
The evaluation board also has the capability to measure the current consumption of the sensor in
any of its operating modes, allowing the use to accurately assess real world power use over time.
Alternatively, the sensor can be completely separated from all the other electronics on the
evaluation board and controlled directly by the user via edge connectors. All data, control and GPIO
pins of the sensor can be connected to connectors, J3, J4 and J5. Power is provided via a separate
edge power connector (J2), via USB (J1), or directly via header (J5).
For more technical information on the sensor, download the appropriate data sheet from here:
https://www.gassensing.co.uk/products/

CozIR®-LP3 Evaluation Board User Guide
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USB DRIVER
To interface to a PC, the evaluation board requires a USB-A to USB-Mini B cable and a USB driver to
function correctly. Recent versions of Windows will automatically identify and install the USB driver
when you plug in the lead.
If the USB driver is not installed, or the evaluation board will not connect to a COMM port, please
download the USB driver from the FTDI website:
https://www.ftdichip.com/Drivers/VCP.htm
Choose “VCP Drivers” and select the correct driver for your operating system.
SOFTWARE INSTALLATION
The GSS evaluation board software is available direct from the GSS web site. Download the .zip file
to your computer. Unzip and click on Setup.exe and follow the instructions on the screen.
INSTALLING THE SENSOR
The sensor needs to be connected to the board. Rotate the fixing cams out of the way to allow
insertion of the sensor. When the sensor is correctly seated on the pin headers, rotate the cams into
place, clamping the sensor into place.
Insert the sensor before applying power to the board or connecting the USB interface. Refer to
figure 2 on the following page of this user manual to determine the correct sensor orientation.

CozIR®-LP3 Evaluation Board User Guide
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EVALUATION BOARD CONCEPT
Figure 1: Evaluation Board Key Components
The evaluation board consists of a USB interface device, which connects to an on-board
micro-controller. The on-board microcontroller connects to the sensor using either its UART
or I2C interface. The interface mode is user selectable.
The microcontroller also interfaces to the environmental monitoring sensors. The board
comes with temperature, humidity, and pressure sensors.

CozIR®-LP3 Evaluation Board User Guide
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Figure 2: Top Side Evaluation Board
Figure 3: Bottom Side Evaluation Board

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STANDALONE OPERATION
The sensor can be completely isolated from the rest of the evaluation board electronics. This allows
the user to conveniently control the sensor directly via edge connectors J3, J4 and J5. To operate in
this manner, the DIP switches (S5) must be set to isolate the sensor from the microcontroller by
putting them into the off position.
Figure 3: DIP Switches (S5, shown in OFF position)
The evaluation board is shipped with the DIP switches set ON (see label on switch) to connect the
sensor to the on-board microcontroller by default. To isolate the sensor from the on-board
microcontroller, set the switches to OFF. Power supply connections to the sensor are described in
the following section.
The sensor switch connections on the DIP switches are listed below.
SWITCH POSITION
NAME
TYPE
DESCRIPTION
1
Rx_In
Digital Input
UART Receive Input
2
Tx_Out
Digital Output
UART Transmit Output
3
NC
Unused
Do not connect (For internal use only)
4
PWR_ON
Digital Input
Sensor Power On Enable pin.
-Power on – High
-Power off – Low
5
ALARM
Digital Output
Alarm Output
6
READY
Digital Output
Data ready pin. Pulsed high when data
ready
7
I2C_SDA
Digital Input/Output
I2C serial data input/output. Pull-up
resistor to VDD is provided on the
evaluation board.
8
I2C_SCL
Digital Input
I2C serial clock input. Pull-up resistor to
VDD is provided on the evaluation
board.
9
I2C_ENABLE
Digital Input
Set low for I2C interface mode. Leave
floating to select UART interface mode.
Pin status detected at power on.
10
PWM_RS485
Digital Output
PWM Output

CozIR®-LP3 Evaluation Board User Guide
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SENSOR POWER SUPPLY
If the sensor is to be evaluated in isolation and separately from the evaluation board USB interface
and software, it must be provided with power. There are three methods to provide power to the
sensor. Note the sensor must be powered via the USB interface if the GSS evaluation software is to
be used.
Method 1 - External Power Supply
The sensor can be supplied from an external power source via the connector (J2). This connector
can accept either a 2.5mm or 2.1mm standard DC 5V power supply barrel plug. This drives a low
noise low drop out (LDO) regulator, which supplies the sensor via a FET switch. The state of the FET
switch is controlled by the state of the PWR_On pin, accessed via connector J5, pin 4.
The LDO regulator provides a stable 3.3V output to the sensor. To enable this mode of operation,
switch S1 should be set to external power (EXT PWR). The LDO input voltage range is a nominal 5V to
15V.
Method 2 - USB Power Supply
Power can be provided from a USB source. Plug J1 into a USB power source and set switch S1 to USB
power (USB PWR), see picture below. This drives a low noise low drop out (LDO) regulator, which
supplies the sensor via a FET switch. The state of the FET switch is controlled by the state of the
PWR_On pin, accessed via connector J5, pin 4. The LDO regulator provides a stable 3.3V output to
the sensor.

CozIR®-LP3 Evaluation Board User Guide
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Method 3 - Variable External Power Supply
The user can also drive the sensor directly with an external power supply, bypassing the on-board
low noise LDO and FET switch. This allows the user to evaluate the behaviour of the sensor with
different supply voltages or power sources. To enable this mode of operation, the following settings
need to be configured.
Connector/Jumper
Setting
Sensor Connection
J5, pin 1
Connect to external GND
GND
J5, pin 2
Connect to external VDD
VDD
PL2
Remove jumper. Isolates sensor from
rest of the evaluation board
-
S2
Set to OFF. Isolates LDO from sensor.
-
The evaluation board has pull-up resistors for the I2C serial data input/output lines in each of these
modes. They pull-up to either the on-board 3.3V supply, or the external VDD on J5, pin 2.
All the sensor connections are enumerated on connectors, J3, J4 and J5. For a full description of the
sensor connections and functions, please refer to the latest version of the data sheet at,
https://www.gassensing.co.uk/products/.