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
PINOUT I/O DESCRIPTION
| 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) |
arduino
- Nice library, but inside repository https://github.com/richardhmm/DIYRepo/tree/master/arduino/libraries/DSM501
- interrupt driven version https://github.com/Sovichea/dsm501-interrupt/
I tried both of them and on my module they don't report sane results when compared with other sensors.
platformio
https://primalcortex.wordpress.com/2020/05/23/an-esp8266-air-quality-monitor-based-on-the-dsm501a-dust-sensor/
https://github.com/fcgdam/ESP8266_AirQuality
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
Pins:
| 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.
