XPicoWiFi/DeveloperGuide

Connecting xPico Wi-Fi to a microcontroller

The xPico Wi-Fi has four serial interfaces that you can use to connect to your microcontroller:

• 2 UART interfaces
• 1 SPI Master interface
• 1 USB Device full speed interface

The UART interface is the simplest to implement, as it requires no driver or special protocol.

UART interfaces

Hardware

Both UART interfaces (referred as Line 1 and Line 2) can have baud rates up to 921kbps, and only require the TX and RX pins connected to a microcontroller to work. In addition, Line 1 can also use RTS and CTS lines for hardware flow control. Both lines can use XON/XOFF software flow control.

SPI interface

The SPI interface is a Master interface, which can be controlled with the Lantronix SmartSuite Monitor application.

USB interface

The USB interface is a full speed (12 mbps) Device interface. It will be enabled in future firmware.

Serial port communication/protocol

As part of the Lantronix SmartSuite of serial port applications, the xPico Wi-Fi offers multiple applications that can run on the serial ports.

• Tunnel
• Modem Emulation (AT Commands)
• Monitor (scripting engine)
• Mux (serial API)
• Command Line Interface

You can choose a combination of these applications to run on each Line. Which application runs will depend on your microcontroller and the application.

Tunnel

Configure all the connection details before deploying your device.

• Setup the server to send data to or listen for incoming connections
• Data is transparently tunneled to/from the serial port to the TCP port at the other end
• Configurable for:
  • Start/End characters
  • Automatically reconnect
  • Timeout disconnect
  • Packing/flushing
• xPico Wi-Fi manages all networking

Modem Emulation (AT Commands)

Control the network connection at run-time.

• Easy to use, familiar AT commands
• Device controls where the connection is made
• xPico Wi-Fi manages all networking
• Can also listen for connections with ATA command

Monitor

Connect directly to sensors, display on local web server

• xPico Wi-Fi will query sensors
  • Periodically (poll)
  • On request by Web Browser (control)
• Programmable filtering and parsing of returned data
• Filtered data stored in on-module RAM
• Can access data via Javascript/AJAX from browser

Mux

Manage multiple connections from one serial port

• xPico Wi-Fi still manages all networking, including web server, TCP sockets, etc.
• Microcontroller can switch, with a simple API:
  • Sending/receiving data to server
  • Listening on a TCP port
  • Get data to/from the webserver at a specific URL
• Up to 4 concurrent connections
• Data is streamed directly to/from network connection to serial port, no limits because of RAM space