RTX41xx. Wi-Fi Module

Transcription

1 RTX41xx Wi-Fi Module Module variants covered by this document: RTX4100 RTX4140 Application note AN8 Software Access Point Mode (Soft AP) Application note SoftAP RTX41xx Wi-Fi Module 1

2 CONTENT 1 Introduction General Description Document History Document References Soft AP A short disambiguation Soft AP in the RTX41xx module Examples of Applications using Soft AP Easy WEB configuration of network SSID Configuration Menu Set Wi-Fi Access Point subpage Set IP Config subpage Telnet configuration of network SSID etc Secure Point-to-Point data transfer Application note SoftAP RTX41xx Wi-Fi Module 2

3 1 Introduction 1.1 General Description The purpose of this document is to present all the functionalities of the RTX41xx Software Access Point (Soft AP) feature introduced in the SDK since the version Document History V1.0 Initial release MAD V1.1 PM V1.2 Added screenshots PM V1.3 Added limitations of TM SoftAP functionality V1.4 Added WEB TM configuration V1.5 SoftAP security PM considerations added V1.6 added WebServer to TM the list of reference apps using the Easy Web Configuration feature V1.6 Added RTX4140, TM added cable replacement application V1.7 TM V1.8 Updated Easy Web TM Config screen shots based on Platform/SDK release / WPA2 limitations removed Disclaimer: This document can be subject to change without prior notice. 1.3 Document References [QS6]. RTX4100_Quick_Start_Guide_Exosite_QS6.pdf. [QS8]. RTX4100_Quick_Start_Guide_2Lemetry_QS8.pdf. Application note SoftAP RTX41xx Wi-Fi Module 3

4 2 Soft AP With the emergence of ubiquitous wireless communication, an increasing need to connect devices directly to each other without the need of an Access Point (AP) has arised. 2.1 A short disambiguation There are several terms that often come up when talking about direct Point-to-Point (P2P) communication. To avoid any confusion a brief description of the typical options is provided below. Thereafter, the capabilities of the RTX4100 is discussed. Ad-hoc network An ad-hoc network is a general term describing several devices connected together without the need of a central connecting device such as a Router, a Switch or an AP. It refers to the whole network, which can include several nodes having all the same routing capabilities (in general). In can use Wi-Fi, but also any other type of radio communication (Bluetooth, Zigbee, DECT, etc.) The term Ad-hoc networking is mostly used to describe an older method for devices to create simple Point-to-Point connections using s Independent Basic Service Set (IBSS). Wi-Fi Direct Wi-Fi Direct is a newer standard by the Wi-Fi Alliance that allows two (or more) devices to connect to each others without the need of an AP, to communicate using Wi-Fi technology. Any device embedding the Wi-Fi Direct feature should support a software Access Point (soft AP) as well as WPS mechanisms for easy pairing etc. Application note SoftAP RTX41xx Wi-Fi Module 4

5 Data tethering In the case of Wi-Fi, data tethering is often used to connect a device with Internet access to another device without access. Once connected, both devices have access to Internet through the device providing data tethering. Typically, the internet connected device will act as an Access Point often with router (layer 3) functionality. Soft AP Software Access Point / Soft AP can be as simple or as complex as the role requires. As opposite to the Ad-hoc and Wi-Fi Direct, Soft AP has more static roles, meaning that only one of the devices has the Soft AP capabilities (Server or AP) while the connected device(s) can only be client (STA). The device setup as Soft AP may or may not provide data tethering. Application note SoftAP RTX41xx Wi-Fi Module 5

6 2.2 Soft AP in the RTX41xx module Soft AP is a very useful functionality of the RTX41xx module. It enables a direct connection either between two RTX41xx modules, or between a RTX41xx and another Wi-Fi device. The Soft AP feature of the RTX41xx does not provide data tethering as such, as there is no router or internet backhaul as a traditional Access Point. But the RTX41xx can easily relay data to an application inside the RTX41xx or over a physical bus (UART, SPI etc.) to a host processor. Soft AP should not be seen as an application in itself, but rather as a functionality to improve other applications, like supporting P2P transfers or small, embedded web browsers. The RTX41xx platform firmware and SDK supports Soft AP mode with the following characteristics. Features: No security (open) or WPA2 PSK security Configurable Pre-Shared Key (PSK) from the application Configurable SSID from the application SSID broadcast or no broadcast Standard IP address of Small DHCP server available Limitations: Only support for one connected client at the time When in SoftAP mode the RTX41xx can not operate as a client at the same time Application note SoftAP RTX41xx Wi-Fi Module 6

7 2.3 Examples of Applications using Soft AP To jumpstart your application development, RTX has developed a couple of reference applications using the Soft AP functionality. The following sections describe the reference applications included in the SDK showing the use of the Soft AP feature. The included reference applications are just examples of the multitude of possible applications using the Soft AP functionality Easy WEB configuration of network SSID The Soft AP mode can be used for easy WEB configuration of network parameters and other application parameters through a small embedded web server. A user can turn on his RTX41xx module and broadcast an SSID. The user can then connect his PC or smartphone to the RTX41xx. The client will automatically get an IP address from the RTX41xx. The user can then open his browser and access the small, embedded web server where it is possible to enter the SSID and PSK of the internet AP as well as other application parameters. After this configuration, the RTX41xx will restart as STA / Wi-Fi client with the user application and connect to the configured Access Point. The easy WEB configuration feature enables SSID and PSK configuration on RTX4100 based products not having a MMI suitable for entering this information during setup, and is thus a very usefull feature when using access points not supporting WPS. Important: In addition to the natively build in configurations possible with the easy WEB configuration, it is also possible to add and change the layout and functionality of the build in web server. This makes the Easy WEB configuration an easy way to add custom web pages hosted directly from the RTX41xx module. The RTX41xx platform firmware and SDK supports Easy WEB configuration with the following characteristics. Features: HTTP parser HTTP response encoding Web page managing Default Easy WEB configuration pages: Configuration menu (Main page), Set Wi-Fi Access Point, Set IP config Support for customizing the main page and adding subpages in CoLA The Exosite, 2lemetry and WebServer reference applications use the SoftAP mode in combination with the Easy WEB configuration feature of the RTX41xx platform, making it possible to easily configure the network SSID etc. The Exosite and 2lemetry cloud reference applications are described in more detail in ([QS6]) and ([QS8]). In the following the Easy WEB configuration feature used in the Exosite, 2lemetry and WebServer reference applications is described. In order to access the Easy WEB configuration a WiFi enabled PC may be used as describe in the following. First enable the Easy WEB configuration in the RTX41xx module. See how to enable Easy WEB configuration in when using the Exosite and 2lemetry reference applications in ([QS6]) and ([QS8]). Use a PC to scan for the Soft AP setup by the RTX41xx module. The advertised SSID is RTX41xx followed by the three last bytes of the RTX41xx MAC address. When the correct SSID is displayed select it and press connect in the wireless network connection setup window. Application note SoftAP RTX41xx Wi-Fi Module 7

8 Select the advertised SSID is RTX41xx followed by the three last bytes of the RTX41xx MAC address and click connect. Enter the Network key rtx41xxpass, and click connect. Application note SoftAP RTX41xx Wi-Fi Module 8

9 The status of the network should now change to Connected. The Easy WEB configuration page is displayed when accessing the fixed IP address in a browser after connecting to the RTX41xx Soft AP. The native supported Easy WEB configuration html page consists of a main page and two subpages. 1. Configuration Menu 1.1. Set Wi-Fi Access Point 1.2. Set IP Config Application note SoftAP RTX41xx Wi-Fi Module 9

10 Configuration Menu Headline text can be changed by CoLA Possible to add custom text below headline Click Reboot the module to restart the module after completing configurations Click to enter Set Wi-Fi Access Point subpage Click to enter Set IP Config subpage Custom subpages can be added here by CoLA CoLA application name and build time and date. Platform firmware version. AR41xx firmware version. RTX41xx MAC address Figur 1 Configuration menu entry page Application note SoftAP RTX41xx Wi-Fi Module 10

11 Set Wi-Fi Access Point subpage The Set Wi-Fi Access point subpage is used to configure the RTX41xx with the settings needed to associate with the desired accesspoint after exiting the Soft AP mode. Enter SSID of the access point that the RTX41xx shall be associated to Select the security mode, options: none, WPA, WPA2, WEP Select encryption mode, options: AES, TKIP Enter the pass key for the access point Enter WEP key index if required, options: 1,2,3,4 Click save settings to load the settings into the RTX41xx module Before RTX41xx enters Soft AP mode a scan for available accesspoint is done. The result is displayed for information only Figur 2 Set Wi-Fi Access Point subpage Click Cancel to return to the Configuration menu main page Application note SoftAP RTX41xx Wi-Fi Module 11

12 Set IP Config subpage The Set IP config subpage is used to configure the RTX41xx for either DHCP of static IP settings to be used when connecting to the IP network after exiting the Soft AP mode. Select between DHCP or static IP When static IP is selected above enter IP address, subnet and default gateway Click save settings to load the settings into the RTX41xx module Click Cancel to return to the Configuration menu main page Figur 3 IP Config subpage Application note SoftAP RTX41xx Wi-Fi Module 12

13 2.3.2 Telnet configuration of network SSID etc. The TempSensorSoftApCfg embeds the TempSensor application (records the Temperature of the MCU and reports it at fixed intervals through UDP) combined with a Soft AP functionality. Its purpose is to configure an RTX41xx module to connect to a given AP, knowing its SSID and key, then run the TempSensor application This application demonstrates an alternative way to configure the RTX41xx using Telnet instead of the HTTP based WEB configuration. In a first phase, the RTX41xx runs as a Soft AP. One connects to the RTX41xx using Wi- Fi. Then connects to the RTX41xx using a telnet client and sends the SSID and the key of the target AP as a terminal string. In the second phase, the module then stops its Soft AP functionality, and becomes a client to connect to the target AP using the SSID and key received in phase 1. Once connected, it starts sending Temperature data at regular intervals Secure Point-to-Point data transfer The SoftApTcpServer embeds a TCP Server inside the module setup as a Soft AP. One can simply connect to it through Wi-Fi with any device (e.g. a laptop) and send TCP packets to it. It is then easy to modify the reference application so that the Soft AP relays the data over the UART or becomes a client, connects to an AP and reports this data to a server on the internet, for example. Examples of applications using Point-to-Point data transfer is cable replacement applications. Soft AP can also be used to demonstrate fast or low latency P2P connections between two RTX41xx modules, simply through the use of the SoftApTcpServer and the TcpClient reference applications running on each RTX41xx. In the case of two RTX41xx modules communicating, WPA2-PSK and DHCP server may be enabled on the Soft AP side. Application note SoftAP RTX41xx Wi-Fi Module 13