Data Sheet

Silicon Labs
Page 26 of 45
10 Firmware
WF121 incorporates firmware which implements a full TCP/IP stack and Wi-Fi management. Exact features
will depend on the firmware version used. Please see the documentation of the firmware for exact details.
There are two main ways to use the module: Host controlled and script controlled.
Host controlled means an external host is physically connected to the module and it sends simple commands
to the module and one of several different host interfaces can be used. The module provides high level APIs
for managing Wi-Fi as well as data connections. Bluegiga provides a thin API layer (BGLib) written in ANSI C
for the host which can take care of creating and parsing the messages sent over the transport. For evaluation
purposes GUI tools and a library for python are also provided.
IP
BGAPI
802.2 LLC
802.11 MAC
UART /
USB
/
SPI
Host
UDPTCP
BGLib
(implements BGAPI)
Application
MLME
802.11 PHY
HTTP, FTP,
SMTP etc.
DHCP, TFTP,
DNS etc.
Figure 8: WF121 software
Data can be routed either through the API or through another physical interface. For example if the first UART
is used for sending and receiving command events, a TCP/IP socket can be bound to the second UART and
data written to the UART will seamlessly be passed to the TCP/IP socket. For information about the latest
capabilities of the firmware, please refer to the WF121 API reference documentation accompanying it.
The module can also be controlled by a script running on the module. This is especially useful for simple
applications as it eliminates the need for a host controller and can drastically cut development time. In
combination with a host it can also be used automate certain features such as the serial to TCP/IP
functionality described above.