General user interface

The user interface consists of several USB ports, an audio jack, an ePaper display, 4 buttons and 3 red LEDs.

The USB-C port at the front panel directly connects to the STM32 micro controller and can be used for flashing the MicroPython firmware, uploading the MicroPython based user application and its debugging. This port is also used for charging the internal LiPo battery.

The micro-USB port at the front panel provides 2 virtual USB interfaces: one for directly communicating with the Quectel BG-77 modem via AT commands and the other is a unidirectional interface for getting debug messages from the modem only.

The slide switch switches the device on, which is indicated by the red LED on the far right (seen at the top view).

The micro-USB port at the right side panel is dedicated to updating the firmware of the Quectel BG-77 modem.

The audio jack at the rear panel can be used for plugging in a headphone and connecting to the PCM audio codec chip. Using this interface by software functionalities is planned for the future.

The SMA plug is for connecting a 5G antenna. Please pay attention to the correct frequency when selecting a suitable antenna.

The ePaper display is mounted on the top of the LiPo battery. The display is used together with the 4 buttons to operate the device.

Apart from the right red LED to indicate the power supply status, the other two LEDs are used in the user application. For example, the middle LED is used to indicate that data transmission is in progress.

User application

Important note:
While running a test, the user interface of the device becomes unresponsive due to extensive communication with the modem via AT-commands.

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Video tutorial of Boot and initialization.

Video tutorial of Attach to narrow band IoT network.

Video tutorial of Detach from network.

Video tutorial of Manual transmit to backend.

Video tutorial of Ping IPs.

Video tutorial of Show UE stats.