UMAX141200. Wi-Fi to CAN Converter. Version 1
Page: 7-44
2 CONVERTER DESCRIPTION
The Wi-Fi to CAN Converter is a simple device converting CAN frames into UDP or TCP IP
datagrams and sending them over a wireless Wi-Fi network. The device can also convert the
received UDP or TCP datagrams into CAN frames.
The converter has one CAN port. It supports a high-speed CAN with a configurable baud rate
up to 1Mbit/s and a dual-band 2.4GHz and 5GHz 802.11 a/b/g/n Wi-Fi. All standard and
extended CAN frames, including data and remote frames, are supported.
The converter can work in a station (STA) or access point (AP) mode. The wireless connection
is provided by an internal antenna to maintain ruggedness. A three-color LED on the housing
displays an internal state of the converter.
The converter contains a web server to setup configuration parameters and monitor the
internal state of the converter using a web browser. The user can also update the converter
firmware over the air (OTA) using the web browser.
The converter has two digital inputs. One of them is used to switch the converter to a default
AP mode and then access it using a standard wireless device (e.g., a laptop or a smartphone).
The second one can be used to disable all Wi-Fi communication.
A simple command-line
AxioDisc.exe
Windows application is provided to locate a converter
on the LAN.
To ensure low latency in processing CAN messages, the converter software runs under control
of a real-time operating system.
The converter is designed to work on off-road machinery or in a harsh industrial environment
with power transients, high humidity, and vibrations.
2.1 Hardware Block Diagram
The converter hardware block diagram is presented in Figure 1.
The converter is powered from a standard automotive 12V or 24V battery. Reverse polarity,
overvoltage, and transient protection is provided.
The CAN port is connected to a powerful 32-bit ARM Cortex-M4 microcontroller that runs IP
protocol stack and all IP to CAN conversion logic.
The wireless part is provided by the Texas Instrument CC3135 network processor (NWP),
which sends and receives IP messages over a wireless Wi-Fi network, establishes and
maintains the wireless connection in 2.4GHz or 5GHz Wi-Fi frequency band.
The converter has two digital inputs. They have internal pull-up resistors and are activated by
connection to the digital ground (DIN_GND pin).
A three-color RGB Status LED indicates the internal state of the converter.
