Elektroda.com
Elektroda.com
X

Search our partners

Find the latest content on electronic components. Datasheets.com
Elektroda.com

Suspended dust sensor SDS011 PM2.5 PM10 - commissioning, test

TechEkspert 9915 36
This content has been translated » The original version can be found here
  • The laser SDS011 sensor from Nova Fitness is available on auction portals for ~ $ 20 SDS011 . The device has an air inlet and an air suction turbine. 5V power supply, UART communication interface works with 3.3V voltage level. Information about PM2.5 and PM10 dust measurements is available as incoming data via UART interface or as variable filling of square waveforms available on the interface. Through the UART interface, we can put the device into sleep mode, and configure operating modes, e.g. cyclical entering into sleep mode and waking up to perform the measurement. Information about the sensor can be found on the manufacturer's website: SDS011 . A USB UART converter was delivered with the device, but due to the binary format of the output data, I used Arduino UNO to test the module.

    The life of the sensor is limited to 8000 hours, so it is worth taking measurements cyclically, e.g. every 15 minutes, starting the device for 30 seconds. During operation, the sensor consumes ~ 65mA, while in sleep mode ~ 2mA. The air suction turbine produces a low hum during operation.

    In a closed room, the display values fluctuated around ~ 10-20ug / m3. When the air intake is blocked, the displayed values have dropped to single units. Opening the window increased the value to several dozen. I also went to the sensor area airly receiving similar indications (different by + -10). I have no other way of checking the device, but it seems to be working fine.
    [movie: 27efcedd85] https://filmy.elektroda.pl/8_1541353265.mp4 [/ movie: 27efcedd85]

    In the Arduino environment you will find many libraries to help you run the sensor, just search for the phrase SDS011, e.g. https://github.com/lewapek/sds-dust-sensors-arduino-library The communication protocol is quite well described in the specification on the manufacturer's website, so to first attempts, makeshift code can be used.

    Below is the test code, after uploading it to the Arduino UNO, connect the appropriate pins of the module to the RX / TX. In the serial console we will see the values of the concentration of PM2.5 and PM10 in the air sucked in by the sensor.
    [syntax=c]byte data_buff[10];
    byte data_count=0;
    byte data_rdy=0;

    void setup() {

    Serial.begin(9600);
    }

    void loop() {
    byte data;
    int pm25,pm10;


    if(Serial.available() > 0){
    data = Serial.read();

    if(data_rdy==0){
    if(data_count==0 && data==0xAA){
    data_buff[data_count]=data;
    data_count++;
    }else if(data_count==1 && data==0xC0){
    data_buff[data_count]=data;
    data_count++;
    }else if(data_count>1 && data_count 0){
    data = Serial.read();

    if(data_rdy==0){
    if(data_count==0 && data==0xAA){
    data_buff[data_count]=data;
    data_count++;
    }else if(data_count==1 && data==0xC0){
    data_buff[data_count]=data;
    data_count++;
    }else if(data_count>1 && data_count

    Cool! Ranking DIY
    Can you write similar article? Send message to me and you will get SD card 64GB.
    About Author
    TechEkspert
    Editor
    Offline 
    TechEkspert wrote 3355 posts with rating 2682, helped 11 times. Been with us since 2014 year.
  • #2
    Dawid90u
    Level 23  
    Hi,
    I also have the above-mentioned smog sensor. I am designing a small station that measures temperature, pressure, humidity and pollution. Unfortunately, the project goes on and on due to lack of time, but you can already see the end.
    How will you transport the air samples to the sensor? Outside or inside sensor and through the tube? I will have everything in the housing and exposed to the window. That is why I used a chamber made by myself with a heating spiral to heat the air in front of the air inlet in the sensor. The point is that the water vapor does not cause distortions. I haven't done the tests yet if the solution works. But I recommend that you consider eliminating the problem with this pair and the strange results it caused.

    best regards
  • #3
    TechEkspert
    Editor
    Thanks for the hint. The sensor will be close to the window, and the display will be deep in the room. I have two options: the sensor outside the window in a junction box or in another housing with air inlet and outlet, the second option is a pipe led out of the window. Since there is a problem with the steam, maybe I will use a tube and the inside will contain a metal section?

    Unfortunately, there can be much more harmful factors in the air than this sensor can detect, but I thought that I had to start somewhere.
  • #4
    blue_17
    Level 32  
    I tested about 10 different pollution sensors, even a design was made based on my experience.

    https://web.facebook.com/smoksensor/

    Recently, I even read a report on low-cost smog sensors prepared, among others, by AGH and several other entities.

    In general, sensors require calibration before use, then they show reasonably well.

    The company from Krakow uses the fifth generation plantower pms5003 sensor in its designs, has a relatively large working chamber, but usually overestimates the indications at higher concentrations, of course when it comes to the raw samples themselves.

    As of today, such solutions are outdated because you could give a newer sensor at the same price and replace wifi with something like lora.
    Unfortunately, it is impossible to directly compare the results of the older and newer generation, all detectors must be replaced.

    When it comes to air sample conditioning, a certain group of sensors, due to their structure and method of operation, has no problem with that.

    The laser sensors work well in the range of 20 to 60% humidity and are unlikely to have any problems. Unfortunately, the temperature is usually a bigger problem because the detectors usually work only down to -10 degrees according to the manufacturer with a given measurement error.

    Unfortunately, you can either have a handy sensor or a shaft where the air will be dried, pre-filtered and heated.

    At this point, you can choose freely if the power supply is not battery powered.
  • #5
    AGrodecki
    Level 14  
    qwerty
    asdfg
    zxcvb

    Moderated By Mirek Z.:

    One example of destroying your posts - some attempts (in the patches panel) were preventable. Warning.

  • #6
    MiiiM
    Level 11  
    I use this sensor at home to control my own air purifier. The sensor wirelessly communicates with the purifier and the latter, based on its indications, controls the operation of the fan. It works fine and in my opinion it is more useful in this form (at least in short term).
    Because the number of external sensors in Krakow is so large that it is easier to follow the preview of whether it is worth going out "to the fresh air" in the application, while what gets into the apartment and what we still breathe, I prefer to check and filter ourselves.
  • #7
    gdL
    Level 27  
    I am curious if you can develop your own sensor using a 3D printer to create its housing and a phototransistor (too slow?) Or a photodiode (faster) IR in tandem with a rail to rail operational amplifier and, of course, an IR or laser emitting diode. It seems not a seemingly difficult, but interesting task. Commercial sensors are of course calibrated, but their cost is slightly higher.
    A self-made sensor should cost a total of
  • #8
    blue_17
    Level 32  
    Hello

    The most "classic" dust sensor is a photo diode transimpedance amplifier and a transmitting diode with a lens.

    I saw a design with a printed chamber was ok, but you can't do it for $ 5, the biggest problem in such designs is the shape of the chamber and setting the barrier in relation to the transmitter and receiver.

    There is still calibration, where in typical workshop conditions it is a difficult process without even semi-professional equipment or a handful of experience.

    Here you have a ready reference design from TI they used the existing sensor (chamber, barrier) they added their electronics - at the beginning it is enough

    http://www.ti.com/tool/TIDA-00378

    It's all in the details ;)

    best regards
  • #9
    cas-it-solutions

    Level 3  
    I recommend a sensor that I bought recently:

    https://allegro.pl/laserowy-czujnik-smogu-8w1...?reco_id=43e609f0-e0e2-11e8-9f25-246e9677f8d8

    The sensor has a high-quality built-in laser detector that provides a very accurate measurement (3 built-in sensors-detectors).
    Additionally, the color marking of the measured parameters (PM2.5, HCHO, TVOC) informs us about the air condition.

    I have already done a lot of comparative measurements with a diagnostic station in Wroc³aw or with a sensor on a home purifier and I am pleased when it comes to welding the level for PM2.5 and PM10. However, when it comes to car exhaust fumes, I have mixed feelings towards it, because standing next to a busy street in Wroc³aw, it did not show any changes in air quality.

    The harmful compounds released by car exhaust fumes include:

    - carbon monoxide CO (I asked the manufacturer for details if the sensor was able to detect it)
    - HC hydrocarbons and their derivatives, in many cases interchangeably referred to as volatile organic compounds VOC (this is precisely detected by this sensor as TVOC - volatile organic compounds)
    - nitrogen oxide (oxide and dioxide);
    - sulfur oxides (oxide, dioxide, trioxide);
    -lead and its compounds;

    ref: https://autokult.pl/9882,spaliny-silnikow-co-zawieraja-i-jak-to-wplywa-na-czlowieka-2
  • #10
    TechEkspert
    Editor
    The topic of dehumidification and sensor calibration is something new to me. I wonder how they calibrate? They throw a measured amount of dust into a container of a certain volume and after starting the fan inside, they receive a "mixture" with a certain concentration? Or is it always a calibration against a reference sensor?

    After what you wrote in the topic, I already understand why there are several hundred simple airly sensors the size of a pack of cigarettes in Poland:
    https://airly.eu/map/pl/
    and there are several dozen professional air monitoring stations the size of a container:
    http://pompie.gios.gov.pl/pjp/current

    This is a similar situation to the professional Perun lightning detection stations:
    http://old.imgw.pl/index.php?option=com_content&view=article&id=91&Itemid=111
    http://www.pogodynka.pl/burze/
    and amateur: http://pl.blitzortung.org/station_list.php

    It seems that both approaches and both systems are needed, although they have different characteristics.
  • #11
    CosteC
    Level 32  
    Only gentlemen, you forget that such drying will also bind some of the dust on the wet elements of the dryer and the measurement will be low. Heating it up won't do that. In both cases, battery operation should be forgotten. I would not exaggerate with electricity bills - the heater can be turned on for 5 minutes every hour and rather not 2 kW but 20 W.
  • #12
    Robstar
    Level 17  
    If you want to expand the station with additional sensors, e.g. humidity, it is good to add the Scheduler library, delay stops the whole process.

    I have a station on pms7003 + esp8266 outside and the temperature drift of the readings was visible in the summer at higher temperatures.
  • #13
    blue_17
    Level 32  
    You always have to center or a small number of professional stations distributed according to EU directives sometimes in bad places but sometimes there was no better idea to please the EU :( or exercising with cheap sensors, but only if we have at least semi-professional calibration equipment.

    In my opinion, if heating the air was so important, the leading suppliers of sensors from Japan and China would take it into account in their projects - they also have fog and winter ;) unfortunately most of it indoor air quality sensors

    I saw only one DIY sensor project where the sensor box was heated with small 5V heating panels, unfortunately the heating of the can does not equal the heating of the chamber, rather electronics.

    Cheap sensors do not count particles, but read the values from the photoelement and convert them into an analog signal.

    Professional digital sensors work differently, you need to know that in the case of sensors with several ranges, one value is most often measured, and the others are approximated as only "some" manufacturers mention ;)
  • #14
    czareqpl
    Level 30  
    I would recommend a smaller solution than the sensirion SPS30.
  • #15
    TechEkspert
    Editor
    Something new this SPS30, how with availability? I can only see in digikey.
  • #16
    czareqpl
    Level 30  
    Democrats have LT of a dozen or so weeks due to the drought in FTDI on FT232RL, similarly, the SPS30 itself has approximately 12 weeks of LT. Recently I ordered samples and they will not arrive until December, but if someone wants to have a digikey already :)
  • #17
    TechEkspert
    Editor
    When they come in December, is there a chance for material about them?
  • #18
    czareqpl
    Level 30  
    I can scratch something when I take a borrowed demo from a client because I don't want to stick to the adapters ;)
    Besides, I can also upload a presentation from the manufacturer.
    Measurements during final tests were carried out in Beijing. The results coincided by 97% with those from the US embassy about 2km away from the Swiss embassy where the sensor was mounted.
  • #20
    blue_17
    Level 32  
    czareqpl wrote:
    Measurements during final tests were carried out in Beijing. The results coincided by 97% with those from the US embassy about 2km away from the Swiss embassy where the sensor was mounted.


    Could you give us a link to details?

    In my opinion, if the detector will actually be calibrated, and the lifetime according to the manufacturer is 8 years with 24/7 operation, which I doubt, the price of PLN 200 is not excessive.
    I would be happy to test and compare because we have a good time to do it, and I still have several different detectors.

    What does VIEP say about low cost sensors?
    By the way, in the link, have a look at the professional "dust sensor from the link" ;)

    http://pompie.gios.gov.pl/pjp/content/show/1000919

    "Air pollution measurements using low-cost sensors

    Offered on the commercial market, the so-called low-cost sensors for air pollution measurements, in particular for measurements of suspended dust concentrations PM10 and PM2.5 in the air, are not devices operating in accordance with the reference methodology described above. Due to the lack of proven equivalence of the methods used in low-cost sensors to the reference methodology, they cannot be treated as a source of reliable data, and on their basis it cannot be determined whether air quality standards have been exceeded (permissible, target, information or alarm levels) and quality assessment air.

    For the above reasons, these sensors are not used for air quality measurements carried out under the State Environmental Monitoring.

    Often the location of low-cost sensors used by individuals or as part of various types of projects does not meet the requirements set out in the Regulation of the Minister of the Environment of September 13, 2012 on assessing the levels of substances in the air because they are installed in places that are not representative of a given area for example, on balconies, by windows, on roofs, trees, etc.

    In connection with the above, when tracking information on the Internet on suspended dust concentrations generated by low-cost sensors, it should be borne in mind that these measurements may be subject to a very large error, and in extreme cases they may be completely incorrect, which in turn may lead to could mislead users of this information. "

    And in its report, AGH indicates that after calibrating cheap detectors, they indicate a trend.

    AGrodecki wrote:
    I will only add to the subject in general terms, which is widely underestimated by current radio amateurs (read arduino lovers with rudimentary electronic knowledge).
    Metrology is a serious field. The measurement consists not only of the result, but also, and can even above all, of additional parameters such as resolution and accuracy. Accuracy, in turn, is a complex parameter that includes environmental conditions, instantaneous and long-term errors. The error formula can be a complicated mathematical formula.


    When it comes to models, there are about 11 models spreading pollutants in the air and this is where the mathematics begins, but the components are parameters that the sensors do not measurelike the height of the chimney, the velocity of the exhaust gases and many others ;)

    Everyone who knows a bit about the problem of dust measurements appreciates that the more expensive detectors were not built in 2-3 weeks, but they had to be backed by strong R&D
  • #21
    tomus2k
    Level 25  
    blue_17 wrote:

    ....
    And in its report, AGH indicates that after calibrating cheap detectors, they indicate a trend.
    ....

    You broke me, it means that cheap detectors have the same measurement quality as a coffee filter stuck to the vacuum cleaner pipe. They should be called toys rather than indicators, detectors.
  • #22
    blue_17
    Level 32  
    Unfortunately, but I can't agree because it's like saying that a multimeter without GUM certification is useless.

    Search the internet for a 3-part report and you can learn a few things from it.

    best regards
  • #23
    TechEkspert
    Editor
    @AGrodecki why are you destroying your posts? What is the point of writing something useful to delete later?

    @ blue_17 is this report generally available somewhere?
  • #24
    gdL
    Level 27  
    Ok, I would like to make such a sensor further, even if it is not calibrated. I would like it to have as few discrete and mechanical elements as possible and, at the same time, the highest possible resolving power.
    1. Can the transmitting element be an IR diode (with a built-in lens) or a red laser? I cannot use additional lenses, and even if I did, it would make the project unavailable to 95% of hobbyists.
    2. Due to the nature of the particles and the activation rate curve, the detector should be a photodiode or a phototransistor?
    3. I would like Attiny to deal with the interpretation of data at the digital level (activation time) and return the percentage distribution of sensor activation times, e.g. after 1Wire (few ports required).
    4. Mechanical design as simplified as possible and ready for 3D printing. But how to force air flow through the body - receiving elements (power resistor or mini DC5V fan)?

    When the project is created, of course it will be open-hardware and I will publish everything on the electrode, and I will not monetize it.
  • #26
    CosteC
    Level 32  
    @gdL I understand you would like an apple looking computer, Alienware performance and scrap price, but please be serious. See for yourself what professional, semi-professional and amateur sensors look like and why they use different optical systems, different light sources (hint - the wavelength is related to scattering on objects of different sizes) and then please think about what data processing the old one should deal with and an inefficient 8 bit microcontroller. And mechanically mounting optical elements in often curved and punctured 3D prints from popular printers is generally a slightly funny idea, although it may be successful

    Specifically:
    1) Maybe, but there will be limitations
    2) Depends on what you count on, with a phototransistor the limits can be painful.
    3) If you like antiques, go ahead
    4A) If you can 3D print the elements with sufficient precision, please let me think it over first. The spread may be too great.
    4B) Fan or resistor depends on assumptions. One guarantees high flow but breaks down, the other is slow and moderately predictable but reliable.
  • #27
    RaStro
    Level 13  
    I am reading this and I am wondering about this passage:
    Dawid90u wrote:
    How will you transport the air samples to the sensor? Outside or inside sensor and through the tube? I will have everything in the housing and exposed to the window. That is why I used a chamber made by myself with a heating spiral to heat the air in front of the air inlet in the sensor. The point is that the water vapor does not cause distortions. I haven't done the tests yet if the solution works. But I recommend that you consider eliminating the problem with this pair and the strange results it caused.


    I am mainly wondering how the heating of the air is supposed to affect the presence of steam (water steam, I assume)? Because the fact of heating the air does not remove steam from it, the only thing that happens is the so-called relative humidity changes, because this one depends on the temperature.
  • #28
    Adamcyn
    Level 38  
    I would like to verify the outdoor air for:
    to ventilate or not to ventilate.

    Are these simple, ready-made sensors available on Allegro suitable for this?
  • #29
    kurkudor
    Level 10  
    czareqpl wrote:
    Democrats have LT of a dozen or so weeks due to the drought in FTDI on FT232RL, similarly, the SPS30 itself has approximately 12 weeks of LT. Recently I ordered samples and they will not arrive until December, but if someone wants to have a digikey already :)

    Hello,
    Have the samples already arrived? I'm interested in this sensor but haven't seen any reviews yet.

    Recently I found out that by ordering PMS7003M sensor from China, you can get PM-G7M: http://www.yuntongkeji.com/pro_d.asp?id=410
    Maybe someone has already had the opportunity to test? Looks like a Plantower PMS7003M clone.
  • #30
    czareqpl
    Level 30  
    I won't have anything until early December.