Hello,

I need some help, I have very little coding knowledge and am trying to adjust this code I downloaded from the Dyson foundation, this was from their engineering tutorial where they created a PM2.5 sensor and a Gas sensor. Youtube video here: https://www.youtube.com/watch?v=USHUJzfM5K0.

I've followed the entire tutorial with one exception, I am not using the gas sensor and its corresponding LED because my project revolves around Particulate Matter (PM). The PM2.5 sensor is a Seeed Studio laser PM2.5 sensor. I believe the code doesn't allow the LEDs to work individually and only knows how to turn on and read the sensors when BOTH sensors are plugged in.

How do I rectify/change the code so that the LED corresponds to the single PM 2.5 sensor?

The link to the code is attached below.

Regards,
Abel
jdf_aqi.zip

So new version will be available in library registry

Tried using the sensor with an ESP32 but it's always saying wrong checkSum!!!!:

4D  0  1C  0  A
0  E  0  10  0
A  0  E  0  10
A  4A  2  E6  0  
7A  0  B  0  2
0  0  wrong checkSum!!!!

sensor num: 28
PM1.0 concentration(CF=1,Standard particulate matter,unit:ug/m3): 10
PM2.5 concentration(CF=1,Standard particulate matter,unit:ug/m3): 14
PM10 concentration(CF=1,Standard particulate matter,unit:ug/m3): 16
PM1.0 concentration(Atmospheric environment,unit:ug/m3): 10
PM2.5 concentration(Atmospheric environment,unit:ug/m3): 14
PM10 concentration(Atmospheric environment,unit:ug/m3): 16

On the other hand, the values read seem to be ok.

Hi, is there also a raspberry example somewhere? I understand that it's not officially supported yet, but from all I can tell, the "Grove Base Hat" has the correct I2C ports for the sensor, and the C++ code doesn't look very complicated ;)
In case there is no example that could get me started, any pointer on what libraries to use on the raspberry instead of Arduino.h and Wire.h?

Any help would be much appreciated :)

Hi.
I wanted to ask if someone experienced something similar. From time to time after starting I2C in ESP32 successfully doing the initialization plus select comm (To disable serial)

I get the wrong readings.
I ported this also to be an ESP-IDF framework component, still testing it, but it seems to deliver the same numbers than my small Arduino and this repository:
https://github.com/martinberlin/HM3301-idf

Just to clarify, what is the right clock speed for I2C?
In the HM330x datasheet it says that for standard I2C mode is 100Khz.
In another post where someone made a python version the developers say to put it at 20Khz.

But still the clock speed does not seem to be a problem for me. Even with 20Khz I'm getting the same effect.
My program is here:
https://github.com/martinberlin/epaper-weather-station/tree/develop/main/SPI-displays
air-quality-station.cpp

I noticed that I get mostly this wrong readings when I toggle the SET pin down with ESP32 (And hold it down during deep-sleep)
If I don't do it the readings seem fine. But then the fan will still rotate and consumption will be too much when connecting with the battery. Any idea of what I could be doing wrong? Or if there is any solution for this?

Below the epaper rendering this when the data comes out wrong.

When I try to verify the code in Arduino Web Editor, this error occurs.

/home/builder/opt/libraries/latest/grove_laser_pm2_5_sensor_hm3301_1_0_2/Seeed_HM330X.h:76:58: error: 'u32' has not been declared

HM330XErrorCode IIC_read_bytes(u8 start_reg,u8 *data,u32 data_len);

^~~

/home/builder/opt/libraries/latest/grove_laser_pm2_5_sensor_hm3301_1_0_2/Seeed_HM330X.h:91:48: error: 'u32' has not been declared

HM330XErrorCode read_sensor_value(u8 *data,u32 data_len);

^~~

When compiling for esp32 a error appears, upsetting everyone who shell use said product.

.../Arduino\libraries\Grove_-_Laser_PM2.5_Sensor_HM3301/Seeed_HM330X.h:91:48: error: 'u32' has not been declared
HM330XErrorCode read_sensor_value(u8 *data,u32 data_len);
^
cc1plus.exe: warning: unrecognized command line option '-Wno-frame-address'
exit status 1

Can anyone help get this working as an ESPHome custom sensor?

The sensor specifications state that there are three channels: 2.5µm, 5µm and 10µm.

The sample code uses PM1.0, PM2.5 and PM10 concentrations.

How does this make sense and which statement is true?