Grove Laser PM2.5 Sensor (HM3301)
Laser-scattering particulate sensor: PM1.0, PM2.5 and PM10 in µg/m³, plus particle counts from 0.3 µm up, on one Grove I2C cable.
Say it to PAL
“Warn me when the fine dust in the air gets unhealthy.”
The code PAL writes
p.onSensorChange('grove-hm3301', 'pm2_5', (pm) => {
if (pm > 35) p.notify('PM2.5 is ' + pm + ' µg/m³ - air is unhealthy for sensitive groups');
});
await p.waitUntilStopped();When to pick it
Use for dust, smoke and PM2.5 air quality. Not a gas sensor: it cannot see CO2, VOCs or carbon monoxide.
Good to know
- Needs 30 s after power-on for stable readings.
- The fan and laser need 5 V; a 3.3 V-only Grove port may not run it reliably.
- Laser particle counters over-read in fog or very humid air (droplets scatter light like dust).
About it
The Seeed Grove Laser PM2.5 Sensor carries a Hynetek HM3301 laser-scattering particle sensor. A fan draws air past a laser; the scattered light is counted and sized, and the module reports mass concentrations for PM1.0, PM2.5 and PM10 in two calibrations (CF=1 'standard particulate' and 'atmospheric environment') plus six particle-count bins from 0.3 µm to 10 µm. Every frame carries a checksum, and a frame that fails it is dropped rather than shown. The module needs 5 V for its fan and laser (the Grove board regulates the 3.3 V logic) and 30 seconds to stabilise after power-on.
Where to buy
Facts
Tested
Its driver works. We have not signed it off on a real board yet.
I2C address
The Grove Laser PM2.5 Sensor (HM3301) answers at I2C address 0x40. The address is fixed.
Board size
80 × 40 mm
The HM3301 board measures 80 × 40 mm and stands 16.6 mm tall with its parts. It has 4 mounting holes. These dimensions are from the maker’s mechanical drawing.
Free to reuse
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This record was last changed on October 25, 2026.