Project Files of W5100 Ethernet Module Library for Proteus: Arduino UDP Node

W5100 ETHERNET MODULE LIBRARY FOR PROTEUS - V1.0 (THE W5100 MODULE, ETHERNET LIBRARY ON SPI)
Designed by The Engineering Projects www.TheEngineeringProjects.com

IMPORTANT LINKS
Article (read it first - pictures, step by step, every feature explained):
  https://www.theengineeringprojects.com/2026/10/w5100-ethernet-module-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/w5100-ethernet-module-proteus-library
The demo talks to our Laptop WiFi Monitor and Mobile WiFi Monitor (both included) - their articles:
  https://www.theengineeringprojects.com/2026/10/laptop-wifi-monitor-library-for-proteus.html
  https://www.theengineeringprojects.com/2026/10/mobile-wifi-monitor-library-for-proteus.html
The demo uses our Arduino UNO V4.0 (included) - its article:
  https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
The same W5100 on the Arduino Ethernet Shield, and the newer W5500 module - our libraries for them:
  https://www.theengineeringprojects.com/2026/10/arduino-ethernet-shield-library-for-proteus.html
  https://www.theengineeringprojects.com/2026/10/w5500-ethernet-module-library-for-proteus.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
W5100-Ethernet-Module-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                                                    201.9 KB   our UNO V4.0, to LIBRARY
|   |-- TEPLAPTOP.LIB                                                        39.5 KB   the laptop, to LIBRARY
|   |-- TEPMOBILE.LIB                                                        13.1 KB   the phone, to LIBRARY
|   |-- TEPW5100MOD.LIB                                                      23.0 KB   the W5100 module, to LIBRARY
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                                      883.5 KB   the UNO V4.0, to MODELS
|   |-- TEPNET.DLL                                                           2.00 MB   module + monitors, to MODELS
|-- Proteus Simulation/
|   |-- TEPARDUINO.DLL                                                      883.5 KB   copy of the model
|   |-- TEPNET.DLL                                                           2.00 MB   copy of the model
|   |-- W5100_UDP_Node.hex                                                   52.6 KB   the UNO of the demo
|   |-- W5100-UDP-Node-with-Laptop-and-Mobile.pdsprj                         27.8 KB   the demo + PC + phone
|-- Arduino Code/
|   |-- W5100_UDP_Node/W5100_UDP_Node.ino                                     5.7 KB   UNO sketch (Ethernet)
|-- README.txt                                                              ~17.1 KB   this file
Total: 6.09 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
The blue W5100 Ethernet module as one Proteus part: a WIZnet W5100 (a hardwired TCP / IP chip with its own 10/100
Ethernet port), a HanRun RJ45 jack with its magnetics and its LINK / ACT LEDs, a 25 MHz crystal, an AMS1117 3.3 V
regulator, a red PWR LED and a 2x5 header - your microcontroller keeps its own sketch, the W5100 does the TCP / IP and
the sockets, a cable joins it to the router.
  * The pins work as on the real module: SCLK, MOSI and MISO (SPI - D13 / D11 / D12 on an UNO), SCS (the W5100's chip
    select; the Ethernet library uses D10 unless the sketch calls Ethernet.init(pin)), RST (LOW holds the W5100 in
    reset; the module pulls it up, so it may stay free), INT (the W5100's interrupt output: HIGH - the Ethernet library
    never enables the interrupts), 5V or 3V3 (either one powers the module) and GND.
  * The model is the W5100 itself, register by register, as the Arduino Ethernet library (2.0.x) drives it: the 4-byte
    SPI frames (0xF0 write / 0x0F read, the address, the data), the common registers (the mode with its reset bit, the
    gateway, the subnet mask, the MAC, the IP address, the retry time and count, the buffer sizes), four sockets with
    their registers and their 2 KB TX / RX buffers (8 KB + 8 KB), and the commands OPEN, LISTEN, CONNECT, DISCON,
    CLOSE, SEND, RECV. It runs the Ethernet library from the Arduino IDE unchanged - the library's own chip test finds
    a W5100 (Ethernet.hardwareStatus() is EthernetW5100).
  * The W5100 has no link register: Ethernet.linkStatus() is Unknown on it, as on the real chip - a sketch cannot see
    the cable (our W5500 module can).
  * DHCP or a fixed address: Ethernet.begin(mac) asks the virtual router's DHCP (U1 gets 192.168.1.101);
    Ethernet.begin(mac, ip, dns, gateway, subnet) takes its address at once. The router answers DNS (name.local of the
    network, any other name = the virtual internet host 203.0.113.10) and NTP.
  * UDP (EthernetUDP) with broadcasts: a packet to 255.255.255.255 (or to 192.168.1.255) reaches every other device on
    the network; packets sent to the broadcast address by the other devices reach the module. TCP client and server
    (EthernetClient / EthernetServer) work as on our Ethernet shields. A ping from the laptop is answered.
  * The LEDs: the red PWR LED (power), and on the RJ45 jack the green LINK (the cable in) and the yellow ACT (it flashes
    with each packet); the cable's blue plug in the port while it is in.
  * The cable: the CABLE property (IN / OUT), a click on the RJ45 jack, or CABLE IN / CABLE OUT in the panel. Out:
    nothing gets through - UDP packets sent meanwhile are lost (UDP has no retries); the TCP connections wait - back
    within 20 s, they carry on; after 20 s without a link they are dropped. In: on the network at once, the same
    address.
The part is drawn our way at the module's size (the blue board, the RJ45 jack at its left end, the 2x5 header at its
right end); its pins leave the right edge, each named beside its end. Modules from different makers order the 2x5
header differently - wire by the names.

ONE DEVICE (search "W5100" in Pick Devices):
  W5100 ETHERNET MODULE  "W5100 Ethernet Module (Ethernet library)" V1.0 (category Peripherals > Ethernet), prefix U,
                         model TEPNET.DLL
  The panel (a TEP pop-up window, the look of the TEP Serial Monitor - our own header, no Windows title bar; it opens at
  Run, the PANEL pad or the W5100 opens it again). Tabs:
    Wi-Fi     a phone with three tabs - BROWSER (OPEN MODULE PAGE: the phone opens the page the Arduino serves on
              PAGEPORT, when the sketch runs a server), ROUTER (the router's clients - the module is listed as LAN) and
              CLOUD (the internet host's requests); ETHERNET CABLE IN / OUT; the cards MODULE (the chip, MAC, the host
              link with its command rate, the LEDs), ETHERNET (router, status, address with gateway and mask, the
              link, DHCP or a static address) and TRAFFIC
    SPI       the Ethernet library's socket commands and the router's DHCP / DNS / NTP answers, newest first (repeats
              counted, x N; a UDP send to the broadcast address is marked so), the link, commands and SPI bytes, the
              sockets (0-3), RST and INT
    Test      web request test (the phone opens the page n times, measured - it needs a sketch with a web server) and
              cable test (the cable pulled for 3 s, measured)
    Settings  theme, text size, open at Run, window size
    Help      report a bug, suggest a feature, article, updates, donate, forum; Copy diagnostics

TEST STATUS
V1.0: verified in Proteus 8.5 on 23 Oct 2026 (the demo project as shipped, the windows off-screen, posted clicks and
keys), and on the PC with the real Arduino Ethernet library 2.0.2 (its W5100 driver, sockets, DHCP and UDP) and the
real demo sketch against the model (13 checks: the chip test, DHCP, linkStatus() Unknown, the beats heard by the laptop
and the phone, commands to the broadcast address and to the node, the answers to the sender only, RATE / STOP / START,
the monitor's STATUS / HELP and a line to everyone). What the Proteus run showed:
  * W5100_UDP_Node: "DHCP... OK", "Chip: W5100", "Link status: unknown (the W5100 has no link register)", "IP address:
    192.168.1.101" and "UDP on port 4210 - beats to everyone every 5 s". The library finds the W5100 0.65 s after Run,
    DHCP takes 0.11 s; PWR and the jack's green LINK lit, the yellow ACT flashes with the packets, the cable's blue plug
    in the port.
  * The beats: "NODE 192.168.1.101: A0=358 (1.75 V) beat 1", 2, 3 ... in the laptop's and the phone's UDP terminals.
  * The laptop (to 192.168.1.255:4210): PING "PONG from 192.168.1.101", A0 "A0=358 (1.75 V)", STATUS "IP 192.168.1.101,
    beats 4 every 5 s, received 3", RATE 2 "beats every 2 s", STOP "beats stopped", START "beats started" (and a beat
    at once), RATE 5. The phone's HELP is answered to the phone only; the phone hears the laptop's commands (they went
    to the broadcast address) but not the answers.
  * The UNO's monitor: "From 192.168.1.21:4210: PING" / "answer: PONG from 192.168.1.101" for every packet; STATUS "IP
    192.168.1.101, beats 6 every 5 s, received 8", HELP, and "Hello from the UNO" sent to everyone - the laptop and the
    phone show "UNO: Hello from the UNO".
  * The laptop's ping: 4 of 4 answered (9 - 15 ms, TTL 255).
  * The panel's SPI page: SEND on socket 0 UDP to 255.255.255.255:4210 (42 B, broadcast), RECV, the answers to
    192.168.1.21:4210 and 192.168.1.41:4210; the sockets: 0 UDP port 4210; RST HIGH - running, INT HIGH.
  * Cable test: off the LAN at once when the cable is pulled, back 0.005 s after it goes back in, the same address.
    Beats 8, 9 and 10 fell in the three pulls: the monitor shows them sent, the laptop never got them - UDP has no
    retries, and on a W5100 the sketch cannot see the cable.
  * Speed: the UNO + the module + the laptop + the phone about 0.12 - 0.15 x real time on our PC (the Ethernet library
    reads the W5100's registers about 49,000 times a second).

INSTALLATION (about 3 minutes)
1. Close Proteus. Extract the WHOLE ZIP to a normal folder (e.g. Desktop).
2. Copy everything in "Proteus Library Files" to the LIBRARY folder of Proteus, for example:
     C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\LIBRARY
   (on some PCs: C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\LIBRARY - use the folder that already holds
   Proteus's own .LIB files). TEPW5100MOD.LIB is the W5100 module; ArduinoV4TEP.LIB our Arduino boards V4.0 (the UNO of
   the demo); TEPLAPTOP.LIB and TEPMOBILE.LIB our Laptop WiFi Monitor and Mobile WiFi Monitor.
3. Copy TEPNET.DLL and TEPARDUINO.DLL from "Proteus Model Files" to the MODELS folder (...\Proteus 8
   Professional\MODELS) - replace older copies (this TEPNET.DLL is the first one that knows the W5100 module; it still
   runs our W5500 module, our Ethernet shields and every Wi-Fi part of the series).
4. Delete TEPW5100MOD.IDX, ArduinoV4TEP.IDX, TEPLAPTOP.IDX and TEPMOBILE.IDX from the LIBRARY folder if they are
   there.
5. The Arduino IDE (only to compile your own sketches - the demo has its HEX file): the Ethernet library is built into
   the IDE (or install it with the Library Manager).
6. Start Proteus. In Pick Devices (P) search "W5100".

RUN THE DEMO
Keep the .hex file, TEPNET.DLL and TEPARDUINO.DLL beside the project in "Proteus Simulation".
  W5100-UDP-Node-with-Laptop-and-Mobile.pdsprj - ARD1 our UNO V4.0 (W5100_UDP_Node.hex, its monitor at 9600 bps) with
  RV1 (POT-HG 10k) on A0, and U1 the W5100 module: SCK, MISO, MOSI and ETH_CS (D10) by net labels, 5V to VCC, GND to
  ground, RST, 3V3 and INT free. PC1 the Laptop WiFi Monitor and MOB1 the Mobile WiFi Monitor - no wires, they are on
  the router's network; their UDP terminals listen on port 4210 (UDPPORT 4210) and send to 192.168.1.255:4210, the
  laptop's ping box holds 192.168.1.101.
  Press Run. The monitor shows DHCP, the chip, "Link status: unknown (the W5100 has no link register)", the address and
  the UDP port; every 5 s a beat goes to everyone ("NODE 192.168.1.101: A0=358 (1.75 V) beat 1") and shows in the
  laptop's and the phone's Terminal. Type PING, A0, RATE <seconds>, STOP, START, STATUS or HELP in either terminal and
  press Send: the answer comes back to that terminal only. In the UNO's monitor: STATUS and HELP; any other line goes
  to everyone as "UNO: ...". The demo serves no page, so OPEN MODULE PAGE and the web request test stay empty.

PINS (beside the module's right edge)
  5V, 3V3   power: either one (the module's AMS1117 makes 3.3 V from 5 V)
  GND       ground
  SCS       the W5100's chip select (LOW = selected)
  SCLK, MOSI, MISO   SPI (MISO is the W5100's while SCS is LOW, else it floats)
  RST       LOW holds the W5100 in reset; free or HIGH = running (the module's pull-up)
  INT       the W5100's interrupt output: HIGH (the Ethernet library does not enable interrupts)
Without power (5V or 3V3) and GND the module is off (the panel shows "no power").

THE DEMO SKETCH (Arduino Code)
  W5100_UDP_Node  Ethernet.init(10); Ethernet.begin(mac) until DHCP answers; prints Ethernet.hardwareStatus() and
                  Ethernet.linkStatus() (Unknown); EthernetUDP on port 4210; every 5 s a beat to 255.255.255.255:4210 -
                  "NODE <ip>: A0=<a0> (<volts> V) beat <n>"; udp.parsePacket() / remoteIP() / remotePort(): PING, A0,
                  RATE <1..60>, STOP, START, STATUS, HELP answered to the sender only; the monitor's STATUS and HELP,
                  other lines broadcast as "UNO: ..."; Ethernet.maintain() renews the lease.

PROPERTIES (double-click the W5100 module > Edit Properties)
  ROUTER    the router the cable goes to - the network name of the Wi-Fi parts (default TEP-WiFi)
  CABLE     the Ethernet cable at Run: IN (default) or OUT
  PANEL     the phone's tab at start (BROWSER, ROUTER, CLOUD)
  PAGEPORT  the port OPEN MODULE PAGE opens (default 80)
  CLOCK     the clock of NTP and the panel: PC (UTC), or a start time YYYY-MM-DD HH:MM:SS (UTC)
Every run starts again from the properties. With DHCP the address follows the part's number: U1 192.168.1.101, U2 .102
... - give every network part its own number, and a fixed address that no other part uses. The laptop is 192.168.1.21,
the phone 192.168.1.41.

LINKS.INI (OPTIONAL)
The Help page cards open web pages. To point them somewhere else without a new DLL, put a text file named links.ini next
to TEPNET.DLL with lines KEY=URL, for example:
  ARTICLE=https://www.theengineeringprojects.com/...
Keys: WEBSITE, FORUM, BUG_REPORT, FEATURE_REQUEST, ARTICLE, USER_GUIDE, UPDATE_CHECK, DONATE. Only http:// and https://
links are used; lines starting with # are comments.

TROUBLESHOOTING
* Ethernet.begin() returns 0 and hardwareStatus() is EthernetNoHardware: check SCLK / MISO / MOSI, SCS (and
  Ethernet.init(pin) when it is not D10), 5V or 3V3 and GND, and that RST is not held LOW.
* DHCP never answers: the cable is out (the panel shows CABLE OUT) - put it in, or click the RJ45 jack. The sketch
  cannot see it: linkStatus() is Unknown on a W5100.
* A terminal hears nothing: its UDP port must be the sketch's (4210) - the terminal's Local port box.
* An answer goes to the wrong terminal: answers go to udp.remoteIP() / udp.remotePort() - the sender of that packet.
* A paused simulation shows the SIMULATION LOG: click the Schematic Capture tab.
* No panel: click the PANEL pad (or the W5100), or turn "Open the panel at Run" back on (Settings).

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot, the serial monitor text, the simulation log and the Copy diagnostics
text of the panel:
  https://www.theengineeringprojects.com/forum/category/w5100-ethernet-module-proteus-library

SUPPORT US
This library is free. If it saves you time, please support our work:
  https://www.theengineeringprojects.com/donate

WEBSITE
  https://www.theengineeringprojects.com/

LICENCES AND THIRD-PARTY NOTES
* The W5100 module model, the Laptop / Mobile WiFi Monitors and the network (TEPNET.DLL), the Arduino board models
  (TEPARDUINO.DLL), the symbols and artwork (TEPW5100MOD.LIB, ArduinoV4TEP.LIB, TEPLAPTOP.LIB, TEPMOBILE.LIB) are made
  by The Engineering Projects. The UNO's processor is Proteus's own AVR model (Labcenter); RV1 is Proteus's POT-HG. The
  models use only standard Windows libraries; no Visual C++ redistributable is needed. The C++ source code of the
  models is not included.
* W5100_UDP_Node.hex contains the Arduino AVR core 1.8.6 with its SPI library (LGPL 2.1,
  https://github.com/arduino/ArduinoCore-avr/tree/1.8.6) and the Arduino Ethernet library 2.0.2 (LGPL 2.1,
  https://github.com/arduino-libraries/Ethernet). The libraries are not shipped.
* 203.0.113.10 is a documentation address (no real server).
* Proteus is a product of Labcenter Electronics and is not included. W5100 and WIZnet are names of WIZnet; HanRun of
  Zhongshan HanRun Electronic. This library is not made or endorsed by WIZnet or Labcenter.

REBUILDING THE FIRMWARE (OPTIONAL)
The HEX file is supplied; the Arduino IDE is not needed to run the demo. Open the sketch in Arduino Code with Tools >
Board > Arduino Uno, then Sketch > Export Compiled Binary. Flash / RAM: W5100_UDP_Node 19,150 / 748 bytes (of
the UNO's 32,256 / 2,048; the rest of the RAM is the stack). Put the exported HEX in place of the simulation's .hex.

MODEL SCOPE AND LIMITS
Modelled: the W5100's SPI frames, its common and socket registers, its four sockets with their TX / RX buffers and the
pointer rules the Ethernet library relies on, TCP (client and server, one connection per socket), UDP (with the 8-byte
header of each packet in the RX buffer, broadcasts both ways), the retry timeouts (RTR x RCR) of an address nobody
answers, the soft reset and the RST pin; the router's DHCP, DNS and NTP answers; the PWR LED, the jack's LINK / ACT LEDs
and the cable; the router, the phone and the internet host shared with every TEP network part. Not modelled: IPRAW /
MACRAW traffic (the modes open but carry nothing), PPPoE, the socket interrupts (INT stays HIGH), the PHY's
auto-negotiation (it is always 100 Mbit/s full duplex), the supply's voltage and current. A ping is always answered.
The model's own choices: the cable goes to the same router as the Wi-Fi parts; the LAN answers in about 2 ms; with the
cable out the TCP connections are kept for 20 s; the simulation runs below real time.

VERSION
TEP W5100 Ethernet Module library V1.0 (Oct 2026). Device W5100 ETHERNET MODULE (TEPW5100MOD.LIB / TEPNET.DLL, which
also runs our W5500 module, our Ethernet shields, our Wi-Fi shields and breakouts, our ESP32, ESP8266, Arduino and Pico
W boards, the ESP-01 family, the ESP-07 / ESP-12 modules, the ESP32-WROOM-32 and the Laptop / Mobile WiFi Monitors),
with our Arduino UNO V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL) and the Laptop WiFi Monitor / Mobile WiFi Monitor
(TEPLAPTOP.LIB / TEPMOBILE.LIB). Demo sketch W5100_UDP_Node V1.0.