®
Application Note
SM-UART-04L
Laser Dust Sensor
SM-UART-04L Laser Dust Sensor is designed to operate in a moderate environment and provides excellent
performance. It’s embedded optical design leverages the strength from laser technology, which allows
customers to achieve excellent performance with balanced reliability. SM-UART-04L is an ideal solution for
industrial and consumer applications.
SM-UART-04L laser dust sensor detects dust particle concentration in air by using an optical sensing
method. A laser light emitting diode (laser LED) and a photo sensor are optically arranged in the device. The
photo sensor detects the reflected laser LED light by dust particles in air. The dust sensor can detect small
particles such as, cigarette smoke and distinguish small particles, such as smoke from large house dust, by
the pulse pattern of the signal output.
Features
• Laser Optical Dust
- High Accuracy
- Fast Response
• UART Output
• Compact in Size
• Flexible Mounting Style
Applications
• Indoor Air Quality Monitoring
•
Air Cleaners and Purifiers
• Air Conditioners and HVAC
• Outdoor Dust Monitoring
Amphenol
Advanced Sensors
Figure 1 : Detection Principle
SM-UART-04L Laser Dust Sensor
Block Diagram
Calibration
Calibration carried out with cigarette smoke per GB/T1880
Absolute Maximum Ratings
Absolute Maximum Ratings
Parameter
Supply Voltage
Operating Temperature
Storage Temperature
Operating Humidity
Storage Humidity
1) Non-condensing
(1)
(1)
Symbol
Vcc
T
opr
T
stg
RH
opr
RH
stg
Rating
0 to + 5.5
-10 to 50
-30 to 70
0 to 95
0 to 95
Unit
V
°C
°C
%
%
Electrical Characteristics
Parameter
Particle Size
Detection Range
Resolution
Indication Error
Warm-Up Time
Response Time
Average Trouble-free Working Time
Supply Voltage
Supply Voltage Ripple
Current Consumption
Output (UART)
1) Non-condensing
2 |
Amphenol Advanced Sensors
(2)
Symbol
D
D
reg
R
1 ~100 ug/m
3
100~999 ug/m
3
D
err
t
wup
t
rsp
T
V
CC
V
CC
Ripple
I
CC
(2)
(2)
(2)
Min.
0.3
1
—
—
—
—
—
—
4.8
—
—
Typ.
2.5
—
1
—
—
5
1
40000
5
—
60
3.3V
Max.
10
999
—
+/-10
+/-10
—
—
—
5.2
30
100
Unit
um
µg/m
3
µg /m
3
µg /m
3
%
s
s
hour
V
mV
mA
2) Testing at T=25°C, RH=40-60%
SM-UART-04L Laser Dust Sensor
Connector
Sensor Connector:
CJT A1276WVA-N-2x5P-H72
Equivalent Connector:
Harwin, Inc. M50-3000545; Amphenol FCI 20021311-00010T4LF
Pin #
1
2
3
4
5
6
7
8
9
10
Pin Name
5V
5V
GND
GND
RESET
NC
RXD
NC
TXD
SET/SLEEP
Description
Input Supply Voltage
Input Supply Voltage
Ground
Ground
Reset Pin @3.3V TTL, Low level reset
—
UART Receiver @ 3.3V TTL
—
UART Transceiver @ 3.3V TTL
Working Mode Pin @ 3.3V TTL Floating or high level for normal working condition.
Low level for dormancy mode.
Application Circuit
SM-UART-04L
Application circuit
SM-UART-04L Laser Dust Sensor
Application Notes (Rev. A - October 2018)
| 3
SM-UART-04L Laser Dust Sensor - Communication Protocol
UART
UART Serial Configuration
Baud Rate
Data Bits
Parity
Stop Bits
9600 bps
8
None
1
Default Output UART Frame Format
Head 1
Head 2
H_Length
L_Length
H_D1
L_D1
H_D2
L_D2
H_D3
L_D3
H_D4
L_D4
H_D5
L_D5
H_D6
L_D6
H_D7
L_D7
H_D8
L_D8
H_D9
L_D9
H_D10
L_D10
H_D11
L_D11
H_D12
L_D12
H_D13
0x42
0x4D
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
Version number
Error code 0b0ABCDEFG
A = 1 Laser error
B = 1 Laser alarm
C = 1 High temperature alarm
D = 1 Low temperature alarm
E = 1 Fan error
F = 1 Fan speed compensation start
G = 1 Fan speed alarm
CS = HEAD1 + HEAD2 + … + L_D13
Length = 2 * 13 + 2 (Data+CS)
PM1 = H_D1 * 256 + L_D1 ug/m3 (Standard Smoke, Calculated Value
PM2.5 = H_D2 * 256 + L_D2 ug/m3 (Standard Smoke, Calculated Value)
PM10 = H_D3 * 256 + L_D3 ug/m3 (Standard Smoke, Calculated Value)
PM1 = H_D4 * 256 + L_D4 ug/m3 (Environment, Calculated Value)
PM2.5 = H_D5 * 256 + L_D5 ug/m3 (Environment, Calculated Value)
PM10 = H_D6 * 256 + L_D6 ug/m3 (Environment, Calculated Value)
L_D13
...
H_CS
L_CS
...
...
* We recommend the customers use PM values with the standard smoke.
4 |
Amphenol Advanced Sensors
SM-UART-04L Laser Dust Sensor
Response Mode - Command Frame
Head 1
0x42
Head 2
0x4D
CMD
CMD
D1
DATAH
D2
DATAL
CRC1
LRCH
CRC2
LRCL
CMD
0xE2
DATAH
X
X
DATAL
Description
Get reading
Output
mode switch
Standby
control
Response
Same format as above table
0x42 0x4D 0x00 0x04 0xE1 0x00 0x01 0x74
0x42 0x4D 0x00 0x04 0xE1 0x01 0x01 0x75
0x42 0x4D 0x00 0x04 0xE4 0x00 0x01 0x77
0xE1
X
0x00 – Ask-answer mode
0x01 – Direct output mode
0x00 – Standby mode
0x01 – Working mode
0xE4
X
Dimensions
SM-UART-04L Laser Dust Sensor
Application Notes (Rev. A - October 2018)
| 5