2.5.2 Serial USB Interface

The Wi-Fi Access Point credentials can be reconfigured through a Serial Command Line Interface (CLI) on the AVR-IoT WG Development Boards. This interface may also be used to provide application diagnostic information. To access this interface, use any preferred serial terminal application (Tera Term, CoolTerm, and PuTTy) and open the serial port labeled Curiosity Virtual COM port, with the following settings:

Table 2-2. Serial USB Interface Settings
Baud rateDataParity bitStop bitFlow controlLocal echoTransmit protocol
96008 bitsNone1 bitNoneONCR+LF (Carriage Return + Line Feed)
Note: For Windows® users, the USB serial interface requires the installation of a USB serial port driver, included in the installation of the MPLAB® X IDE.
The user can control the board by typing the command keywords, listed in Serial Command Line Commands:
Table 2-3. Serial Command Line Commands
CommandArgumentsDescription
reset—Reset the settings on the device
device—Print the unique device ID of the on-board ECC device
key—Print the public key of the board
reconnect—Re-establish connection to the Cloud
version—Print the version of the AVR-IoT firmware library
cli_version—Print the command line interface firmware version of the AVR-IoT library
wifi<Network SSID>, <Password>, <Security Option*> Enter the Wi-Fi network authentication details
debug <Debug Options**>Print debug messages to see status of board operation
*- Authorization Type options are available by typing one of the following three numbers to determine the network security option used:
  1. Open – Password and Security option parameters are not required.
  2. WPA/WPA2 – Security Option Parameter not required.
  3. WEP – Network Name, Password, and Security Option (3) Parameter are required when connecting to a WEP network. For example, ‘wifi MCHP.IOT,microchip,3’.

**- The debug option won't work unless the user selects Enable debug messages option in the AVR-IoT Sensor Node Library. Configured Debug Severity level is used to determine messages displayed using debug_printer():

0. Normal – At this level, only standard operating behavior or data are displayed.

1. Warning – At this level, information related to nuance in operation or configuration is displayed.

2. Notice – At this level, alerts or context-specific information is displayed.

3. Info – At this level, operation or variable information relevant to the end application is displayed.

4. Debug – At this level, error messages, state, or run-time variations during problem solving or development process are displayed.

Note: Setting the Debug Severity level also enables the printing of all other information or messages associated with all levels beneath the set Debug Severity level (e.g., Severity level of NOTICE will also result in WARNING and NORMAL level debug messages to also be displayed). Extensive use of Debug logger at ANY severity level requires memory and execution resources which could affect application behavior.
Figure 2-11. Serial Command Line Interface