SPS30

Datasheet SPS30 Particulate Matter Sensor for Air Quality Monitoring and Control ▪ Unique long-term stability ▪ Advanced particle size binning ▪ Superior accuracy in mass-concentration sensing ▪ Small, ultra-slim package ▪ Fully calibrated digital output Product Summary The SPS30 Particulate Matter (PM) sensor is a technological breakthrough in optical PM sensors. Its measurement principle is based on laser scattering and makes use of Sensirion’s innovative contaminationresistance technology. This technology, together with high-quality and long-lasting components, enables accurate measurements from its first operation and throughout its lifetime of more than eight years. In addition, Sensirion’s advanced algorithms provide superior accuracy for different PM types and higher-resolution particle size binning, opening up new possibilities for the detection of different sorts of environmental dust and other particles. With dimensions of only 41 x 41 x 12 mm3, it is also the perfect solution for applications where size is of paramount importance, such as wall-mounted or compact air quality devices. Content 1 Particulate Matter Sensor Specifications 2 2 Electrical Specifications 3 3 Hardware Interface Specifications 4 4 Operation and Communication through the UART Interface 5 5 Operation and Communication through the I2C Interface 11 6 Technical Drawings 17 7 Shipping Package 18 8 Ordering Information 18 9 Important Notices 19 10 Headquarters and Subsidiaries 20 www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 1/20 1 Particulate Matter Sensor Specifications Default conditions of 25 °C and 5 V supply voltage apply to values in the table below, unless otherwise stated. Parameter Mass concentration accuracy1 Mass concentration range Mass concentration resolution Mass concentration size range2 Number concentration range Number concentration size range2 Sampling interval Start-up time Lifetime3 Acoustic emission level Weight Conditions 0 to 100 μg/m3 Value Units μg/m3 100 to 1’000 μg/m3 10 0 to 1’000 1 0.3 to 1.0 0.3 to 2.5 0.3 to 4.0 0.3 to 10.0 0 to 3’000 0.3 to 0.5 0.3 to 1.0 0.3 to 2.5 0.3 to 4.0 0.3 to 10.0 1 8 25 26 10 PM1.0 PM2.5 PM4 PM10 PM0.5 PM1.0 PM2.5 PM4 PM10 24 h/day operation 0.2 m - % μg/m3 μg/m3 μm μm μm μm 1/cm3 μm μm μm μm μm s s years dB(A) g Table 1: Particulate Matter sensor specifications. ΔM.C. [µg/m3] ΔM.C. [%] ±50 ±45 ±40 ±35 ±30 ±25 ±20 ±15 ±10 ±5 ±0 ±50 ±45 ±40 ±35 ±30 ±25 ±20 ±15 ±10 ±5 ±0 Typical Consistency -10 0 10 20 30 40 50 60 Typical Consistency -10 0 Temperature [°C] Figure 1: Typical consistency tolerance for PM2.5 in µg/m3 between 0-100 µg/m3. 10 20 30 40 50 60 Temperature [°C] Figure 2: Typical consistency tolerance for PM2.5 in % between 100-1000 µg/m3. 1 Deviation to TSI DustTrak™ DRX Aerosol Monitor 8533 reference. PM2.5 accuracy is verified for every sensor after calibration using a defined potassium chloride particle distribution. Ask Sensirion for further details on accuracy characterization procedures. 2 PMx defines particles with a size smaller than “x” micrometers (e.g., PM2.5 = particles smaller than 2.5 μm). 3 Validated with accelerated aging tests. Ask Sensirion for further details on accelerated aging validation procedures. Lifetime might vary depending on different operating conditions. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 2/20 1.1 Recommended Operating Conditions The sensor shows best performance when operated within recommended normal temperature and humidity range of 10 – 40 °C and 20 – 80 %RH, respectively. 2 Electrical Specifications 2.1 Electrical Characteristics Default conditions of 25 °C and 5 V supply voltage apply to values in the table below, unless otherwise stated. Parameter Supply voltage Idle current Average supply current Max. supply current Input high level voltage (VIH) Input low level voltage (VIL) Output high level voltage (VOH) Output low level voltage (VOL) Conditions Idle-Mode Measurement-Mode First ~200 ms after start of Measurement-Mode - Value 4.5 to 5.5 2.31 < 0.99 > 2.9 < 0.4 Units V mA mA mA V V V V Table 2: Electrical specifications. 2.2 Absolute Minimum and Maximum Ratings Stress levels beyond those listed in Table 3 may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these conditions cannot be guaranteed. Exposure to the absolute maximum rating conditions for extended periods may affect the reliability of the device. Parameter Supply voltage VDD Interface Select SEL I/O pins (RX/SDA, TX/SCL) Max. current on any I/O pin Operating temperature range Storage temperature range Operating humidity range ESD CDM (charge device model)4 Electromagnetic field immunity to high frequencies5 High frequency electromagnetic emission6 Low frequency electromagnetic emission7 Rating -0.3 to 5.5 V -0.3 to 4.0 V -0.3 to 5.5 V ±16 mA -10 to +60 °C -40 to +70 °C 0 to 95 %RH (non-condensing) ±4 kV contact, ±8 kV air 3 V/m (80 MHz to 1000 MHz) 30 dB 30 MHz to 230 MHz; 37 dB 230 MHz to 1000 MHz 30-40 dB 0.15 MHz to 30 MHz Table 3: Absolute minimum and maximum ratings. 4 According to IEC 61000-4-2. According to IEC 61000-4-3. 6 According to CISPR 14. 7 According to CISPR 22. 5 www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 3/20 3 Hardware Interface Specifications The interface connector is located at the side of the sensor opposite to the air inlet/outlet. Corresponding female plug is ZHR-5 from JST Sales America Inc. In Figure 3 a description of the pin layout is given. Pin 1 Pin Name Description Comments 1 VDD Supply voltage 5V ± 10% UART: Receiving pin for communication 2 I C: Serial data input / output TTL 5V and LVTTL 3.3V compatible UART: Transmitting pin for communication 2 I C: Serial clock input TTL 5V and LVTTL 3.3V compatible Leave floating to select UART Pull to GND to select I2C 2 Pin 5 RX SDA 3 TX SCL Figure 3 The communication interface connector is located at the side of the sensor opposite to the air outlet. 4 SEL Interface select 5 GND Ground Table 4 SPS30 pin assignment. The SPS30 offers both a UART8 and an I2C interface. For connection cables longer than 20 cm we recommend using the UART interface, due to its intrinsic robustness against electromagnetic interference. 3.1 Physical Layer The SPS30 has separate RX and TX lines with unipolar logic levels. A transmitted byte looks as in Figure 4. Bit Time (1/Baudrate) Start Bit Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Stop Bit Figure 4 Transmitted byte. 8 Universal Asynchronous Receiver Transmitter. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 4/20 4 Operation and Communication through the UART Interface VDD VDD (1) Master TX RX (2) Master RX TX (3) NC SPS30 Connector SEL (4) The following UART settings have to be used:  Baud Rate: 115’200 bit/s  Data Bits: 8  Parity: None  Stop Bit: 1 GND (5) Figure 5 Typical UART application circuit. 4.1 SHDLC Frame Layer On top of the UART interface, the SPS30 uses the very powerful and easy-to-implement SHDLC9 protocol. It is a serial communication protocol based on a master/slave architecture. The SPS30 acts as the slave device. Data is transferred in logical units called frames. Every transfer is initiated by the master sending a MOSI 10 frame. The slave will respond to the MOSI frame with a slave response, or MISO11 frame. The two types of frames are shown in Figure 6. Frame Content MOSI Frame Start (0x7E) ADR CMD L (1 Byte) (1 Byte) (1 Byte) TX Data 0...255 Bytes CHK (1 Byte) Stop (0x7E) Frame Content MISO Frame Start (0x7E) ADR CMD State L (1 Byte) (1 Byte) (1 Byte) (1 Byte) RX Data 0...255 Bytes CHK (1 Byte) Stop (0x7E) Figure 6 MOSI and MISO frames structure. Start and Stop Byte (0x7E) The 0x7E character is sent at the beginning and at the end of the frame to signalize frame start and stop. If this byte (0x7E) occurs anywhere else in the frame, it must be replaced by two other bytes (byte-stuffing). This also applies to the characters 0x7D, 0x11 and 0x13. Use Table 5 for byte-stuffing. Original data byte Transferred data bytes 0x7E 0x7D, 0x5E 0x7D 0x7D, 0x5D 0x11 0x7D, 0x31 0x13 0x7D, 0x33 Table 5 Reference table for byte-stuffing. Example: Data to send = [0x43, 0x11, 0x7F]  Data transmitted = [0x43, 0x7D, 0x31, 0x7F]. 9 Sensirion High-Level Data Link Control. Master Out Slave In. Frame direction from master to slave. 11 Master In Slave Out. Frame direction from slave to master. 10 www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 5/20 Address The slave device address is always 0. Command In the MOSI frame the command tells the device what to do with the transmitted data. In the MISO frame, the slave just returns the received command. Length Length of the “TX Data” or “RX Data” field (before byte-stuffing). State The MISO frame contains a state byte, which allows the master to detect communication and execution errors. The first bit is reserved for future use. Figure 7 shows the composition of the Status byte. b7 0 b6 b0 Execution error code Figure 7 Status byte structure. The execution error code signalizes all errors which occur while processing the frame or executing the command. The following table shows the error codes which can be reported from the device. Note that some of these errors are system internal errors which require additional knowledge to be understood. In case of a problem, they will help Sensirion to localize and solve the issue. Error Code dec hex 0 0x00 1 0x01 2 0x02 3 0x03 4 0x04 40 0x28 67 0x43 Meaning No error Wrong data length for this command (too much or little data) Unknown command No access right for command Illegal command parameter or parameter out of allowed range Internal function argument out of range Command not allowed in current state Table 6 Reference table for error codes. Data The data has a usable size of [0…255] bytes (original data, before byte-stuffing). The meaning of the data content depends on the command. Checksum The checksum is built before byte-stuffing and checked after removing stuffed bytes from the frame. The checksum is defined as follows: 1. Sum all bytes between start and stop (without start and stop bytes). 2. Take the LSB of the result and invert it. This will be the checksum. For a MOSI frame use Address, Command, Length and Data to calculate the checksum. For a MISO frame use Address, Command, State, Length and Data to calculate the checksum. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 6/20 Example (MOSI frame without start/stop and without byte-stuffing): Adr CMD L Tx Data 2 Bytes CHK 0x00 0x00 0x02 0x01, 0x03 0xF9 The checksum is calculated as follows: Adr CMD L Data 0 Data 1 0x00 0x00 0x02 0x01 0x03 Sum 0x06 LSB of Sum 0x06 Inverted (=Checksum) 0xF9 4.2 UART / SHDLC Commands The following table shows an overview of the available SHDLC commands. CMD 0x00 0x01 0x03 0x80 0x56 0xD0 0xD3 Command Start Measurement Stop Measurement Read Measured Value Read/Write Auto Cleaning Interval Start Fan Cleaning Device Information Reset Read / Write / Execute Execute Execute Read Read / Write Execute Read Execute Table 7 Reference table for SHDLC commands. 4.2.1 Start Measurement (CMD: 0x00) Starts the measurement12. After power up, the module is in Idle-Mode. Before any measurement values can be read, the Measurement-Mode needs to be started using this command. MOSI Data: Byte # Datatype 0 uint8 1 uint8 Description Subcommand, this value must be set to 0x01 Measurement-Mode, this value must be set to 0x03 MISO Data: No data. Example Frames: MOSI MISO 12 0x7E 0x00 0x00 0x02 0x01 0x03 0xF9 0x7E Empty response frame: 0x7E 0x00 0x00 0x00 0x00 0xFF 0x7E This command can only be executed in Idle-Mode. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 7/20 4.2.2 Stop Measurement (CMD: 0x01) Stops the measurement13. Use this command to return to the initial state (Idle-Mode). MOSI Data: No data. MISO Data: No data. Example Frames: MOSI MISO 0x7E 0x00 0x01 0x00 0xFE 0x7E 0x7E 0x00 0x01 0x00 0x00 0xFE 0x7E 4.2.3 Read Measured Values (CMD: 0x03) Reads the measured values from the module. This command can be used to poll for new measurement values. If no new measurements are available, the module returns an empty response frame. The default measurement interval is 1 second. MOSI Data: No data. MISO Data: If no new measurement values are available: no data. If new measurement values are available: Byte # 0..3 4..7 8..11 12..15 16..19 20..23 24..27 28..31 32..35 36..39 Datatype float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) float (IEEE754) Description Mass Concentration PM1.0 [µg/m³] Mass Concentration PM2.5 [µg/m³] Mass Concentration PM4.0 [µg/m³] Mass Concentration PM10 [µg/m³] Number Concentration PM0.5 [#/cm³] Number Concentration PM1.0 [#/cm³] Number Concentration PM2.5 [#/cm³] Number Concentration PM4.0 [#/cm³] Number Concentration PM10 [#/cm³] Typical Particle Size [µm] Example Frames: 13 MOSI 0x7E 0x00 0x03 0x00 0xFC 0x7E Empty response frame: 0x7E 0x00 0x03 0x00 0x00 0xFC 0x7E MISO Or response frame with new measurement values: 0x7E 0x00 0x03 0x00 0x28 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xD4 0x7E This command can only be executed in Measurement-Mode. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 8/20 4.2.4 Read/Write Auto Cleaning Interval (CMD: 0x80) Reads/Writes the interval [s] of the periodic fan-cleaning. When the module is in Measurement-Mode an automatic fan-cleaning procedure will be triggered periodically following a defined cleaning interval. This will accelerate the fan to maximum speed for 10 seconds in order to blow out the dust accumulated inside the fan. Important notes:  Measurement values are not updated while the fan-cleaning is running.  Set the interval to 0 to disable the automatic cleaning.  Once set, the interval is stored permanently in the non-volatile memory.  The default cleaning interval is set to 604’800 seconds (i.e., 168 hours or 1 week).  If the sensor is switched off, the time counter is reset to 0. Make sure to trigger a cleaning cycle at least every week if the sensor is switched off and on periodically (e.g., once per day). MOSI Data: Read Auto Cleaning Interval: Byte # Datatype 0 uint32 Description Subcommand, this value must be set to 0x00 Write Auto Cleaning Interval: Byte # Datatype 0 uint8 1..4 uint32 Description Subcommand, this value must be set to 0x00 Interval in seconds MISO Data: Read Auto Cleaning Interval: Byte # Datatype 0..3 uint8 Description Interval in seconds Write Auto Cleaning Interval: no data. Example Frames: MOSI MISO Read Auto Cleaning Interval: 0x7E 0x00 0x80 0x01 0x00 0x7D 0x5E 0x7E Write Auto Cleaning Interval to 0 (disable): 0x7E 0x00 0x80 0x05 0x00 0x00 0x00 0x00 0x00 0x7A 0x7E Response frame for “Read Auto Cleaning Interval”: 0x7E 0x00 0x80 0x00 0x04 0x00 0x00 0x00 0x00 0x7B 0x7E Response frame for “Write Auto Cleaning Interval”: 0x7E 0x00 0x80 0x00 0x00 0x7F 0x7E 4.2.5 Start Fan Cleaning (CMD: 0x56) Starts the fan-cleaning manually14. For more details, note the explanations given for the “Read/Write Auto Cleaning Interval” command. MOSI Data: No data. 14 This command can only be executed in Measurement-Mode. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 9/20 MISO Data: No data. Example Frames: MOSI MISO 0x7E 0x00 0x56 0x00 0xA9 0x7E 0x7E 0x00 0x56 0x00 0x00 0xA9 0x7E 4.2.6 Device Information (CMD 0xD0) This command returns the requested device information. It is defined as a string value with a maximum length of 32 ASCII characters (including terminating null character). MOSI Data: Byte # Datatype 0 uint8 Description This parameter defines which information is requested: 0x01: Product Name 0x02: Article Code 0x03: Serial Number MISO Data: Byte # Datatype 0…n string Description Requested Device Information as null-terminated ASCII string. The size of the string is limited to 32 ASCII characters (including null character). Example Frames: Product Name: MOSI MISO 0x7E 0x00 0xD0 0x01 0x01 0x2D 0x7E 0x7E 0x00 0xD0 0x00 0x0D 0x48 0x65 0x6C 0x6C 0x6F 0x20 0x57 0x6F 0x72 0x6C 0x64 0x21 0x00 0xE5 0x7E Article Code: MOSI MISO 0x7E 0x00 0xD0 0x01 0x02 0x2C 0x7E 0x7E 0x00 0xD0 0x00 0x0C 0x78 0x2D 0x78 0x78 0x78 0x78 0x78 0x78 0x2D 0x78 0x78 0x00 0x91 0x7E Serial Number: MOSI MISO 0x7E 0x00 0xD0 0x01 0x03 0x2B 0x7E 0x7E 0x00 0xD0 0x00 0x15 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x30 0x00 0x5A 0x7E 4.2.7 Device Reset (CMD: 0xD3) Soft reset command. After calling this command, the module is in the same state as after a Power-Reset. The reset is executed after sending the MISO response frame. MOSI Data: No data. MISO Data: No data. www.sensirion.com Preliminary – Version 0.9 – D1 – November 2018 10/20 Example Frames: MOSI MISO 0x7E 0x00 0xD3 0x00 0x2C 0x7E 0x7E 0x00 0xD3 0x00 0x00 0x2C 0x7E 5 Operation and Communication through the I2C Interface Usage:  I2C address: 0x69  Max. speed: standard mode, 100 kbit/s  Clock stretching: not used VDD Rp Rp VDD (1) SDA SDA (2) SCL SCL (3) SPS30 Connector SEL (4) GND (5) Both SCL and SDA lines are open drain I/Os. They should be connected to external pull-up resistors (e.g. Rp = 10 kΩ). Important notice: in order to correctly select I2C as interface, the interface select (SEL) pin must be pulled to GND before or at the same time the sensor is powered up. Figure 8 Typical I2C application circuit. Some considerations should be made about the use of the I2C interface. I2C was originally designed to connect two chips on a PCB. When the sensor is connected to the main PCB via a cable, particular attention must be paid to electromagnetic interference and crosstalk. Use as short as possible (< 10 cm) and/or well shielded connection cables. We recommend using the UART interface instead, whenever possible: it is more robust against electromagnetic interference, especially with long connection cables. 5.1 Transfer Types Set Pointer Sets the 16-bit address pointer without writing data to the sensor module. It is used to execute commands, which do not require additional parameters. 9 1 P P P P P P P P 7 6 5 4 3 2 1 0 ACK P P P P P P P P 15 14 13 12 11 10 9 8 ACK A6 A5 A4 A3 A2 A1 A0 ACK SDA Pointer Address Write I2C Header 9 1 9 SCL 1 S I2C Address www.sensirion.com W A Pointer MSB A Pointer LSB A P Preliminary – Version 0.9 – D1 – November 2018 11/20 Set Pointer & Read Data Sets the 16-bit address pointer and read data from sensor module. It is used to read sensor module information or measurement results. The data is ready to read immediately after the address pointer is set. The sensor module transmits the data in 2-byte packets, which are protected with a checksum. 1 9 D D D D D D D D 7 6 5 4 3 2 1 0 ACK 9 A6 A5 A4 A3 A2 A1 A0 ACK 1 Read Data 0 Read 9 P P P P P P P P 7 6 5 4 3 2 1 0 ACK P P P P P P P P 15 14 13 12 11 10 9 8 I2C Header ACK A6 A5 A4 A3 A2 A1 A0 ACK SDA Pointer Address Write I2C Header 9 1 9 ... ... SCL 9 1 9 ... S ... D D D D D D D D 7 6 5 4 3 2 1 0 D D D D D D D D 7 6 5 4 3 2 1 0 9 1 Checksum C C C C C C C C 7 6 5 4 3 2 1 0 NACK 1 C C C C C C C C 7 6 5 4 3 2 1 0 Read Data (n-1) ACK D D D D D D D D 7 6 5 4 3 2 1 0 Read Data (n-2) ACK ... Checksum ACK Read Data 1 1 ACK 1 9 1 9 ... I2C Address ... W A Pointer MSB Data 1 A A Pointer LSB Checksum 0 A A P ... S Slave Address R A A Data (n-1) Data (n-2) Data 0 A A ... Checksum A P It is allowed to read several times in succession without setting the address pointer again. This reduces the protocol overhead for periodical reading of the measured values. Set Pointer & Write Data Sets the 16-bit address pointer and writes data to the sensor module. It is used to execute commands, which require additional parameters. The data must be transmitted in 2-byte packets which are protected by a checksum. 1 9 1 9 1 Checksum C C C C C C C C 7 6 5 4 3 2 1 0 ACK 9 Write Data 1 D D D D D D D D 7 6 5 4 3 2 1 0 ACK 1 D D D D D D D D 7 6 5 4 3 2 1 0 ACK 9 Write Data 0 P P P P P P P P 7 6 5 4 3 2 1 0 ACK P P P P P P P P 15 14 13 12 11 10 9 8 ACK A6 A5 A4 A3 A2 A1 A0 ACK SDA Pointer Address Write I2C Header 9 1 9 ... ... SCL D D D D D D D D 7 6 5 4 3 2 1 0 1 D D D D D D D D 7 6 5 4 3 2 1 0 9 1 Checksum C C C C C C C C 7 6 5 4 3 2 1 0 ACK ... Write Data (n-1) ACK Write Data (n-2) ACK 1 9 1 9 ... S Slave Address W A Pointer MSB A Pointer LSB ... www.sensirion.com A ... Data 0 A Data 1 A Checksum A Data (n-2) A Data (n-1) A Checksum A P Preliminary – Version 0.9 – D1 – November 2018 12/20 5.2 Checksum Calculation The Read and Write Commands transmit the data in 2-byte packets, followed by an 8-bit checksum. The checksum is calculated as follows: Property Name Protected Data Width Polynomial Initialization Reflect Input Reflect Output Final XOR Example Value CRC-8 read and/or write data 8 bit 0x31 (x^8 + x^5 + x^4 + 1) 0xFF false false 0x00 CRC(0xBEEF) = 0x92 uint8_t CalcCrc(uint8_t data[2]) { uint8_t crc = 0xFF; for(int i = 0; i < 2; i++) { crc ^= data[i]; for(uint8_t bit = 8; bit > 0; --bit) { if(crc & 0x80) { crc = (crc