Free Technical support available for those who want to produce and adapt the firmware. The sensor Tag project has its own category on the new Home Smart Mesh forum



  • nRF52840 on a MS88SF2 module.
  • i²C bus scl P1.13 and sda P1.15
  • Light sensor VEMLS6030 @0x48
  • MS8607 with relative humidity @0x40, pressure and temperature @0x76
  • Reset button P0.18 and user button SW0 P1.09
  • RGB LED P0. 04 06 08

Schematics repo :


Zephyr firmware repo :

Produced udp packets from the nRF52840 are directly text json packets

This is the script that converts the ipv6 udp packets to MQTT posts

This is all the python code that has to run on server side :

while True:
    data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
    message = data.decode("utf-8")
    parts = message.split("{")
    topic = friendly_topic(parts[0])
    payload = '{'+parts[1].rstrip('\n')"'{topic}' => {payload}")

Low power performance

measured with the PPK-II

PeriodAverage Current
deep sleep3.19 uA
sensors acquisition54 uA
wakeup cycle 1.7 sec including RF125 uA

First Produced version v1.0, now v1.1 exist with added LED