Firmware Version 4.4
192.168.4.1
and 192.168.1.32
NMEA4WIFI AP NETWORK
You can operate the NMEA4WIFI multiplexer in two modes: AP or Client Station. In AP (Access Point) mode,
NMEA4WIFI creates a wifi network and smartphones, tablets or computers connect to this wifi network to
receive/send data from/to NMEA4WIFI. In Client Station mode, NMEA4WIFI joins an existing external wifi
network and transmits/receives wifi data on that network. NMEA4WIFI always creates its own
AP network, even when you set NMEA4WIFI to join an existing network.
In this panel, you specify the name and the password of the wifi network that smartphones,
tablets and computers should use to join this network.
When working as an Access Point, NMEA4WIFI uses IP address 192.168.4.1 and
supports DHCP. A maximum of 5 clients can join the network and are assigned
consecutive IP addresses (eg 192.168.4.2 ...). Security is WPA2-PSK. Ssid and Password can have
a maximum of 15 characters and a minimum of 4 and 8 characters, respectively.
When you need to change any setting of NMEA4WIFI you should connect to this network
and then write 192.168.4.1 in the navigation bar of a browser to get the page that you
are reading now.
EXTERNAL NETWORK
If you have already a working wifi network and want NMEA4WIFI to
join that network as a Client Station, you should enter here the authentication parameters that
NEMA2WIFI should use to join this existing network. Ssid and Password can have a maximum and a minimum
size of characters as before. The IP address of the multiplexer on this external network can
be assigned by DHCP or it can be a static one. In order for the multiplexer to obtain an automatic IP from
the network/router you enter 0 in the IP Address text box (this is the default). In order to force a
static IP you need to specify it, exactly, on the IP Address text box. Make sure that you enter an unused IP
belonging to the DHCP pool of the existing network or router. When the connection to an existing network
succeds, the IP address will be shown in the header of this page just below the firmware version number.
SERIAL PORTS SETTINGS
NMEA4WIFI has four input serial ports named as P#1, P#2, P#3 and P#4
and one serial output port, named as P#5.
The baud rate of serial ports P#1 and P#2 is adjustable between 4800, 9600, 19200 or 38400.
The baud rate of P#3 and P#4 can be 4800 or 9600 baud. The baud rate of port P#5 can be 4800, 9600,
19200, 38400, 57600 or 115200. It is important to note that if the baud rate of the
output port is inferior to those of the input ports, data may be lost. Also, all data output by P#5 is
also output by the USB port of the processor module of the multiplexer. Ports P#1 and P#4 have special modes
of operation. If you set USB on the baud rate of port P#1, data from that port is not input from the
PCB connector but, instead, it is read from the USB port of the processor module. In that case data is read
at the baud rate specified on P#5. The special mode of P#4 is called SeaTalk. If you choose that mode
data is assumed to be in the SeaTalk format and it is immediatelly translated to the Nmea 0183 format.
The wide text boxes for each serial ports refer to NMEA0183 sentence filtering. If you do not need sentence
filtering, you enter 0 (zero) in these boxes. See below for an explanation about sentence filtering.
Data received on the input ports P#1, P#2, P#3 and P#4 can be transmitted by output port P#5 or by wifi
either using the UDP port, the TCP port or both.
WIFI SETTINGS
The NMEA4WIFI multiplexer can send and receive wifi data in a "client/server
configuration" where the multiplexer is the server and the connecting devices are the clients.
You can can use either the UDP, the TCP or both internet protocols to send and receive wifi data.
You turn one protocol inactive by setting its port number equal to zero.
Non zero port numbers, either UDP or TCP, should be in range from 1024 up to 65535.
By default, NMEA4WIFI transmits using UDP broadcasting on port number 2000 (compatible with Navionics Sonar
Chart Live). UDP broadcasting assures that all the clients connected to the wifi network
listening to the specified UDP port number will receive the packets sent by the multiplexer.
You should also set the same protocol (UDP or TCP) and the corresponding port numbers on the connection devices
that receive/send data from/to the NMEA4WIFI multiplexer. When you use the TPC protocol, you
need to specify the IP address of the multiplexer. This address, in the case of AP ONLY mode, is
192.168.4.1. If the multiplexer is connected to an external network you specify the IP address that
is assigned by the external network. It is important to note that only one connection with the multiplexer
can be active through the TCP protocol but, at the same time, you can have multiple UDP connections.
The wide text boxes for each wifi ports refer to NMEA0183 sentence filtering. If you do not need sentence
filtering, you enter 0 (zero) in these boxes. See below for an explanation about sentence filtering.
Finally you can set what to do with the received wifi data. It can be be transmitted through the serial output
port P#5 or through the other internet port.
NMEA0183 SENTENCE FILTERING
The 4 input serial ports, the serial output port and the 2 input wifi ports can be
set to pass or to block certain NMEA0183 sentences. This is governed by a filtering string
of up to 43 characters that you can enter in the wide text boxes for each of the ports
referred to. The first character is a number, between 0 and 9. When this number is 0
and nothing follows, no filtering takes place. When this number is 9, the port is ignored
(neither read nor written by the multiplexer). When this number is between 1 and 8, the multiplexer
tests the checksum of the sequence. If it finds a wrong checksum, the sentence is ignored. If the
starting number is between 2 and 8, some sequences are periodically dropped independently of the
rest of the filtering string. For example, if that number is 4, it means that only the 4th sentence
is taken from 4 successive sequences. The first 3 sentences are dropped. The second character is a separator.
The characters "-", ".", "~" and others could be used as separators, but we will use "-". The
third character can only be "A" or "R". "A" means that only the sentences that are referred
to in the rest of the filtering string are ACCEPTED by (pass through) the ports. "R" means
that only the sentences that are referred to in the rest of the filtering string are
REJECTED (blocked) by the ports. Each NMEA0183 sequence is specified by 3 characters
inserted between separators. For example, the string "3-A-RMC-GGA-GLL-GRS-GSA" means
3 things. Firstly, a sentence only passes the filter if it has a correct checksum.
Secondly, only 1 in 3 successive sentences is taken. And finally, the sentence only passes the filter
if it is 1 of the 5 specified sentences. An important note is to understand that the filtering strings for
the UDP and TCP ports refer to data input. No filtering takes place when data is transmitted
by UDP or TCP.
SETTING OPERATING MODES
In addition to the above parameters, you have 4 radio buttons
to choose between: (i) working in AP mode only (ii) also connect as a Client Station (iii) Simulation Mode (iv) Debug Mode.
You press the SET button for NMEA4WIFI to accept the parameters in this page. If there
are no errors in the parameters, NMEA4WIFI changes its operation to the mode and settings selected.
You can use a Windows Programme "Nmea4Wifi.exe" to configure the multiplexer and use a tool
called "Nmea0183Tester.exe" for advanced testing of the multiplexer. The tool
can transmit or record NMEA 0183 data using WiFi or serial communication. Please check www.vela-navega.com/forum
to obtain support for the multiplexer.
HARD RESET and UPDATE
When you press the HARD RESET button the multiplexer loads its factory settings. When you press
the UPDATE button you can check and load the latest available software for the multiplexer. The factory setting uses the following parameters:
Mode: Access Point; Ssid: NMEA4WIFI; Password: 12345678; IP Address: 192.168.4.1; Wifi
Protocol: UDP; UDP Port Number: 2000; Serial Ports P#1, P#3 and P#4 Baud Rates: 4800; Serial Ports P#2 and P#5
Baud Rates: 38400; Serial Output P#5: none; UDP Output: P#1 and P#2.