HL7812 IoT project


I’m currently making a project where I connect a sensor to the cloud.
After doing some research I think that NB-IoT is very interesting because there is no need to make my own gateway.
Since I’m very new to this technologyI still have a couple of questions.

  1. The project is going to be battery powered so I need to use all of the power saving features, any tips on
    keeping the current consumption low? I plan on sending about 4-10 bytes of data every 10s.

  2. The sensor data is going to be accessible via the mqtt protocol but how do I subscribe to the broker?
    Do I send the data to my provider and do they “release” my data in an api or can I connect with the broker
    directly from the module? Keeping in mind that the power consumption needs to be as low as possible.

  3. Do I need an external microcontroller to get the data from my sensor and to the HL module or can the
    module be programmed to do it? The sensor data will be read via UART interface.

  4. I will be making a custom PCB but is there a hardware guide where I can find some more info regarding
    hardware design guidelines?

With kind regards

Hi sebastien.trocherie,

  1. HL7812 support Power Saving Mode, which is defined on 3GPP 27.007

  2. HL device provides connectivity with sim card inserted.
    AT command can be used to make a connection to MQTT broker. You can refer this topic
    TCP/SSL connection failure (HL7802)

  3. I think MCU is needed for sensor data. You can find example on this page. Note that AirVantage acts as a broker in this case:
    Getting started with HL module on RaspberryPI or Linux-based system - av - Sierra Wireless

  4. I’m not familiar with PCB design. You could see the document here:
    AirPrime - HL78xx - Customer Process Guidelines