Shopping List
The core components are an arduino/lmic node. This could be the Cheapest Possible Node. Alternatively ready made PCB’s like Doug LaRue’s PCB or LoRaUK’s PCB are also suitable. Alternatively RN2483 based nodes could also be used but that’s out of scope for this story.
Then you’ll need a Shinyei PPD42NS sensor like used in the DustDuino. Note that because of the need to continuously measure as well as the presence of a heating element this is not suitable for battery operation.
Some links to shops.
NL
Sensor casing https://www.weerstationkopen.nl/nieuwe-producten/98111402-tfa-sensorhut
RFM95 http://webshop.ideetron.nl/RFM95W excl btw
Pro Mini: http://www.tinytronics.nl/shop/Pro-Mini-3.3V-8Mhz?search=pro%20mini
FTDI: http://www.tinytronics.nl/shop/index.php?route=product/product/&product_id=277
Capacitor, level shifter, power supply: Conrad?
PPD42NS: https://www.kiwi-electronics.nl/grove-dust-sensor
China
RFM95: http://www.ebay.com/itm/231784606792?var=531046227200
Arduino Pro Mini: http://www.ebay.com/itm/172421681472?var=471254472226
FTDI: http://www.ebay.com/itm/272429652176?var=571417073476
PPD42NS dust sensor: http://www.ebay.com/itm/Original-PPD42NJ-PPD42NS-Dust-Sensor-SHINYEI-Air-Quality-Monitor-Purifier-/162237452408?hash=item25c61b1078:g:8IUAAOSwOyJX5PqY
5v power supply: http://www.ebay.com/itm/HLK-PM01-AC-DC-220V-to-5V-Step-Down-Power-Supply-Module-Household-Switch-D-/112041806450?hash=item1a16364a72:g:Xt8AAOSwvg9XcxFr
Capacitor: http://www.ebay.com/itm/231913059895
Level shifter: http://www.ebay.com/itm/141728904474