Dobrica Pavlinušić's random unstructured stuff

datasheet: dsm501.pdf

DMS501A - 2mm pin pitch, DMS501B - 2.54 mm

5V, 90mA

1 minute stabilization after power up

sum time of low (0.7v) for measurement interval, divide by time


Pin number Pin name Description
#1 Control Vout 1 control
#2 Vout 2 Vout 2 output factory calibrated PWM output for density of particles over 1 �m.
#3 Vcc Positive power supply DC 5V
#4 Vout 1 Vout 1 output (PWM)
#5 GND Ground


control pin 1

resistor between pin 1 and ground (square pin on board) to control vout 1 output (pin 4)

Resistor value Description
open Preset sensitivity (over 2.5 �m)
47K Half sensitivity (over 1.75 �m)
18.2K Equal sensitivity of Vout 2 (over 1 �m)


I tried both of them and on my module they don't report sane results when compared with other sensors.



dpavlin@nuc:/nuc/esp8266/ESP8266_AirQuality$ git remote -v
origin  https://github.com/fcgdam/ESP8266_AirQuality (fetch)
origin  https://github.com/fcgdam/ESP8266_AirQuality (push)

# edit config
dpavlin@nuc:/nuc/esp8266/ESP8266_AirQuality$ vi src/secrets.h

dpavlin@nuc:/nuc/esp8266/ESP8266_AirQuality$ pio run

dpavlin@nuc:/nuc/esp8266/ESP8266_AirQuality$ pio run -t upload --device-port /dev/ttyUSB2


Wemos D1 +5V DSM501a +5V
Wemos D1 D6 DSM501a PM 1.0 pin
Wemos D1 D5 DSM501a PM 2.5 pin<
Wemos D1 GND DSM501a GND pin

description of similar sensor


power supply

It really needs quiet power supply to get any readings which are not just noise.



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