IoT (LTE) temperature and humidity sensor

Custom design temperature and humidity logger that collects temperature, humidity and location data and sends it to the cloud






BG96 LTE module


Combo LTE/GPS antenna


sht30 humidity and temp sensor


3xAA batteries



C Programming



IP54 rating


Custom shape plastic enclosure


1 x Embedded Engineer

1 x Embedded Programmer

1 x Enclosure designer


Our client needed a custom solution for hardware and firmware of a device that would log temperature, humidity and location data and send it to the cloud.


Hardware requirements:

  • LTE
  • GPS
  • USB for firmware updates
  • Battery-powered (3xAA)
  • Temperature measurements (±0.1°C)
  • Humidity measurements (±1.5%RH)


Software requirements

  • Sending the data to the Cloud
  • Temperature, humidity, and location data logging
  • Changing the frequency of data transfer to the cloud


General requirements

  • The specific shape of the enclosure
  • IP54 rating
  • Minimum 6 months of battery life (for data transfer frequency of 1 time a day)
  • Functional prototype ready for the process of certification


Through the development process of this device, we did our best to reduce the power consumption as the device required long running times on a single battery charge. We carefully picked all of the components to ensure that every mAh of energy is saved.


The device had a specific shape which we had to incorporate with the IP54 rating. This means that the device had to be waterproof while keeping the shape of the device and low manufacturing costs.


The final device was able to last up to a 1 year with data transfers of once a day. W tested the device thoroughly and it was ready for the certification process.

Semblie is a hardware and software development company based in Europe. We believe that great products emerge from ideas that solve real-world problems.