ITEAD/Sonoff sent out a marketing email today which introduced their “AirGuard” lineup of devices. I could not find any reviews for them yet, only a few posts from trade shows. I’m posting this to see if anyone can guess if they will be easy to integrate with Home Assistant or will require custom firmware such as ESPHome.
The three devices are:
SONOFF AirGuard CO2 Matter Over Wi-Fi Air Quality Monitor | SAWF-08P
SONOFF AirGuard PM2.5/PM10 Matter Over Wi-Fi Air Quality Monitor | SAWF-07P
SONOFF AirGuard TH 3.6’’ LCD Zigbee Temperature And Humidity Sensor
I found a device.report certification document which has a teardown of the matter/Wi-Fi devices. It seems like they have a common motherboard with an ESP32-D0WDR2-V3, which is also mentioned on the website. It looks like Sonoff is building two versions of the PM2.5 sensor model with different laser-based modules:
PM2.5 sensor: Plantower PMS9103M
Cubic PM2008M
The CO2 sensor daughter board doesn’t have any identifying information on the silk screen, but the mounted device ‘in a can’ looks like an I2C Sensirion AG SCD41-D-R1. The certification company cut everything open, including the can and removed the mesh.
I am not sure about the LCD controller, it has a 48 pin package, and it looks like it might be a Holtek HT1621 . I cannot be sure if the TM1621 LCD Display - ESPHome - Smart Home Made Simple library is compatible
I’m not super interested or concerned about the humidity/temperature sensor, the other Zigbee Sonoff devices are mostly compatible and don’t use a custom zigbee implementation, like Samsung.
I just received mine. Its easily adding to HA via Matter - see screenshot what it offers. Funfact, HA thinks its a WIFI smart switch.
Compared to my selfmade and calibrated SDC30 sensors, the CO2 readings seem pretty solid, only humidity is way off by 20%, but the values can be calibrated manually on the unit itself.
I think its a nice, solid unit, although I found EUR 50 a bit pricey. However, if you want something working off the shelf, its pretty good I think. Display is nice, although no backlight.
After using it for two days, I have to revert my positiv reply.
The Co2 readings are 190ppm off and cannot be calibrated. I even left the unit outside for a day, hoping it would calibrate around 400ppm, restartet it several times, hoping it to calibrate, but it stayed aroung 590ppm.
The air quality LED is really bright and can not be dimmed, only off/on. Its way to bright for a bedroom at night, lighting up the whole room.
Also, a backlight is missing badly. There is no way to read the display at dim light. This makes it pretty useless in dim rooms, especially because the bright led blinds you at the same time.
I also noticed, when temperature comes down to the freezing point, it does not display the real temperature anymore. but only ‘LL’ which I guess means low.
JoFranke, thank you so much for posting your experience. I suggest contacting Sonoff, at worst they might offer you a coupon on a future purchase, but perhaps they can offer a firmware update to rectify the situation. The CO2 calibration/reading problem has already dissuaded me from purchasing one.
It does seem that right around when I posted, reviewers started posting on YouTube. My apologies for not replying sooner; it seems I don’t have notifications enabled.
