Charlie Evaluation Kit for Cellular LPWA

The example program leverages the hardware building blocks embedded in the Charlie board, namely:

• ME310 modem, supporting GSM, NB-IoT and Cat M1 cellular technologies
• GNSS receiver embedded in Telit ME310 module
• Bosch BMA400 low-power positioning sensor
• User pushbutton and LED

The application is ideal as a demonstration of the board’s features and capabilities. Use it to start developing a wearable tracker with a step counter for older adults or an asset tracker with a user-activated alarm.

The application uses the following libraries:

• BMA400: This library contains a routine set to configure and read the Bosch Sensortec BMA400 accelerometer. It is derived from the standard Bosch Sensortec BMA400 library.
• Arduino ME310 library: This function set makes module configuration and usage easier. It avoids direct use of AT commands to interact with the cellular module.
• Arduino TLT library: This routine set provides high-level access to the modem’s functionalities. It is a loose porting effort of the MKRNB Arduino library, offering the same interfaces when possible.

The application performs the following tasks:

• ME310 modem setup, with the GNSS configured as high priority
• BMA400 sensor setup: The motion sensor is connected to the I2C bus

Once the peripherals are ready, the example application will cycle between the following two operations:

• Sensor read: It will retrieve the number of steps recorded by the BMA400.
• Button status read: If the button has been pressed, the application will trigger an SMS to a predefined number. The SMS text will contain latitude, longitude and the number of steps recorded.

Before running the application, please ensure the following steps are completed:

1. Download and Install the Charlie Board in the Arduino IDE

• 1. Go to the Arduino IDE Preferences.
  2. Under the “Additional Boards Manager URLs” field, paste the following URL: https://raw.githubusercontent.com/telit/arduino-charlie/main/Arduino/package_Telit-board_index.json.
  3. From there, go to Boards Manager and search for “Telit-Board.” This will install the board package for Charlie.
  4. Here’s a short article explaining how to complete this step: https://support.arduino.cc/hc/en-us/articles/360016119519-How-to-add-boards-in-the-board-manager.

2. Download and Install the ME310 Libraries

• 1. URLs for the libraries:
     • https://github.com/telit/arduino-me310-library
     • https://github.com/telit/arduino-tlt-library
  2. Extract both libraries in your Arduino libraries folder or install the new libraries from the ZIP files.
  3. These libraries contain routines to control the ME310G1 module.

3. Download the BMA400 Library

1. 1. URL for the library:
      • https://github.com/telit/arduino-BMA400-API
   2. This library simplifies handling the embedded BOSCH BMA400 accelerometer.

SIM Card and Antenna Requirements

• Please note that not all SIM cards are suitable for NB-IoT and Cat M1 networks. In case your SIM is not enabled for these technologies, the modem will camp on a GSM network as a fallback if available.
• Please check with your provider that the SIM card has a number associated with it and can send SMS messages. If in doubt, insert it in a cell phone and try sending an SMS.
• The antenna supplied with the Charlie kit is wideband and suitable for all LTE and GSM/GPRS bands supported by the ME310G1.

Destination Mobile Phone Number

• Before running the application, the source code must be modified to contain a destination phone number that will receive the alert messages.
• The only required change is to modify the line below, replacing the string between quotes with the destination mobile number:
  • char remoteNum[20] = “+39XXXXXXXXX”;

Additional Resources

• If you wish to send a Google Maps link containing the position, there are many posts and threads on the topic like the one below:
  • https://stackoverflow.com/questions/30544268/create-google-maps-links-based-on-coordinates