Project Files of DS3218 Servo Motor Library for Proteus V1.0 (20kg Digital Servo)

DS3218 SERVO MOTOR LIBRARY FOR PROTEUS - V1.0 (the DS3218 20 kg digital servo with a turning horn and a pop-up panel)
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/ds3218-servo-motor-library-for-proteus-v1-0.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/motor-driver-proteus-library
The demo runs on our Arduino UNO V4.0 (included) - working LEDs, RESET and a
built-in serial monitor, no Virtual Terminal to wire - its own article:
  https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
DS3218-Servo-Motor-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                              201.9 KB   TEP Arduino boards V4.0 (UNO) -> LIBRARY
|   |-- TEPDS3218.LIB                                  25.0 KB   the library -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                883.5 KB   the Arduino board model -> MODELS folder
|   |-- TEPDS3218.DLL                                 296.0 KB   the model -> MODELS folder
|-- Proteus Simulation/
|   |-- DS3218_Servo_Demo.hex                          19.1 KB   the demo firmware
|   |-- DS3218-Servo-Motor-ArduinoUnoV4.pdsprj         22.9 KB   the demo project
|   |-- TEPARDUINO.DLL                                883.5 KB   copy of the board model
|   |-- TEPDS3218.DLL                                 296.0 KB   copy of the model
|-- Arduino Code/
|   |-- DS3218_Servo_Demo/DS3218_Servo_Demo.ino         5.2 KB   the demo sketch (source of the .hex)
|-- README.txt                                        ~20.3 KB   this file
Total: 2.59 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
A simulation model of the DS3218, the 20 kg standard-size digital servo with
metal gears of robot arms, legged robots and RC models. Our own model, not a
symbol on top of Proteus's motor:
  * Its range: 500 - 2500 us = 0 - 180 deg (properties PULSE_MIN / PULSE_MAX).
    The Arduino Servo library's attach(pin) sends 544 - 2400 us, and on a
    DS3218 that is only 4 - 171 deg: use attach(pin, 500, 2500). The demo
    shows both.
  * A digital servo: it takes pulses at 50 Hz up to 333 Hz; a dead band of 3 us
    (0.27 deg). Pulses count from 300 to 3000 us.
  * Inside: the position loop, the DC motor (1.37 ohm, back-EMF), the driver's
    current limit (4.13 A), the metal gearbox, the horn's inertia, end stops at
    -8 and 188 deg. The horn turns at the real speed: about 380 deg/s with no
    load at 5 V - 60 deg in about 0.17 s with the start and the slow-down, 0.13
    s at 6.8 V.
  * The torque: 19 kg.cm at 5 V and 21.5 kg.cm at 6.8 V - the data sheet's two
    points. Above about 5.7 V the driver's current limit holds the torque.
  * The current comes from V+ in the circuit: about 12 mA at rest, up to about
    3.7 A when it starts or stalls at 5 V - a probe or an ammeter on V+ shows
    it. A real DS3218 needs its own supply.
  * Like most servos it is driven only while pulses come: after detach() the
    horn holds by the gears' friction. A pulse beyond the range pushes the horn
    against its end stop (and draws stall current).
  * The load: property LOAD (kg.cm), the load buttons on the pop-up (5 - 20
    kg.cm), or a click on the horn: a 25 kg.cm brake - more than a DS3218 can
    give: it stalls. A load it can carry holds the horn a degree or two short -
    the loop's droop - and the pop-up says so.
  * The mistakes it names: no power or a low V+, SIG stuck HIGH, fast PWM
    (analogWrite) instead of servo pulses, pulses faster than 333 Hz, a pulse
    beyond the range, a stall.
The symbol looks like the real servo seen from the top: the black body with its
two mounting ears and its labels, the silver 25T spline round the output shaft,
the white single-arm horn, the brown / red / orange cable to its plug (GND, V+,
SIG). The horn turns on the schematic to the simulated angle; an orange marker
on the 0 - 180 deg scale shows the angle the pulses ask for. The plate, the
scale, the PWR and SIG LEDs and the strip under the plate (ANGLE, PULSE, CURRENT
and OPEN PANEL) are TEP additions; the real servo has none of them.

ONE DEVICE (search "DS3218" or "servo" in Pick Devices):
  DS3218SERVOTEP   "DS3218 Servo Motor V1.0"   (category Electromechanical >
                  Servo Motors), model TEPDS3218.DLL
  The pop-up panel "TEP DS3218 Servo Motor" opens at Run (and with OPEN PANEL
  on the strip) - the look of the TEP Serial Monitor. Tabs Servo, Graphs, Event
  log and Check; gear and ? icons for Settings and Help; the palette icon
  switches the theme:
    Servo      the state in big letters (HOLDING / MOVING / HOLDING AGAINST
               A LOAD / NO PULSES / STALLED / NO POWER), the dial - the orange
               target and the white horn -, the live values (target, angle,
               pulse, rate, speed, current, supply, load), the signal: one frame
               and the last pulse against the 0 / 90 / 180 deg marks. The
               toolbar: the load on the horn (None, 5, 10, 15, 20 kg.cm) and the
               25 kg.cm brake.
    Graphs     the angle (the horn and the target), the supply current and the
               pulse width over the last 1, 3 or 6 s. Live / Freeze.
    Event log  power, every new target and every move with its time and speed
               ("reached 30.1 deg from 180.1 in 425 ms"), a move stopped short
               by the load, the signal, the load, the warnings; filters All /
               Moves / Warnings, Pause, Clear
    Check      Good for: a servo that does not move, jitters, stops short,
               buzzes or resets the Arduino - the supply, the signal, the pulse
               rate, the pulse widths seen against the servo's range, the
               range, the load against the torque at this supply, the position
               and the current, each with a verdict (green = fine, amber =
               check, red = wrong)
    Settings   theme, text size, open at Run, window size
    Help       report a bug, suggest a feature, article, updates, donate,
               forum; Copy diagnostics for a bug report

TEST STATUS
V1.0: verified in Proteus 8.5 on 30 Oct 2026 (the demo project as shipped: an
A4 sheet, an Arduino UNO V4.0 with its built-in monitor, the DS3218 on D9, RV1
on A0 at 75 %; the pop-up open).
What the runs showed (the horn's angle as the model computed it):
  * The project loads and starts cleanly: "attach(9, 500, 2500): the DS3218's
    0 - 180 deg", "Pot 768 -> Angle 135 deg -> pulse 2000 us"; "reached 134.9
    deg from 90.0 in 149 ms (301 deg/s)", 135 deg held at 12 mA.
  * lib (Servo.h's attach(9)): "attach(9): 544 - 2400 us - on a DS3218 that is
    4 - 171 deg"; the pot's 135 deg became 1936 us = 129.2 deg; typed 0: 544 us,
    the horn at 3.9 deg ("reached 4.1 deg from 129.2 in 360 ms (347 deg/s)");
    typed 180: 2400 us, 171.0 deg ("reached 170.9 deg from 3.9 in 470 ms (355
    deg/s)").
  * full (attach(9, 500, 2500)) and 180: 2500 us, "reached 179.9 deg from
    171.1 in 55 ms"; then 30: 833 us, "reached 30.1 deg from 180.1 in 425 ms
    (353 deg/s)"; knob: "reached 134.9 deg from 29.9 in 307 ms (342 deg/s)".
  * The load (the pop-up's chips) at 5 V: 20 kg.cm and 30 asked - the horn did
    not move: "STALLED at 135.2 deg - the load (20.0 kg.cm) is above its torque
    (19.0 kg.cm at 5.0 V), 3651 mA" (the pop-up: 3660 mA). 15 kg.cm: the horn
    went down and "stopped at 32.4 deg, 2.4 deg short of 30.0 (the load)"; the
    pop-up: "HOLDING 32.0 DEG AGAINST 15.0 KG.CM - 2.1 DEG SHORT (THE LOOP'S
    DROOP)", 1736 mA.
  * sweep: the horn followed the target 1 deg every 15 ms from 0 to 180 deg
    and back.
  * knob again: 135 deg; the Check page all green - "50.0 Hz - right for a
    digital servo (50 - 333 Hz)", "the DS3218 gives 19.0 kg.cm at 5.0 V (19 at
    5 V, 21.5 at 6.8 V)", "12 mA now, 3910 mA peak".
  * The pop-up: Servo, Graphs (1 / 3 / 6 s), Event log, Check - all four pages
    followed the run.
  Plus automatic checks on a PC, 0 failed: 30 on the servo (write(0 - 180)
  with 500 - 2500 us lands within 0.4 deg; attach(pin)'s 544 / 2400 us = 3.9 /
  171.1 deg; 60 deg in 0.172 s at 5 V with the settling, 0.130 s at 6.8 V; top
  speed 381 deg/s; no overshoot; 12 mA at rest; 15 kg.cm gets there within the
  droop (2.2 deg); 20 kg.cm stalls at 5 V and gets through at 6.8 V; 25 kg.cm
  stalls at 3661 mA; 333 Hz pulses work; no pulses = no drive; 2800 us = the end
  stop; analogWrite pulses ignored; SIG stuck HIGH found; 2.5 V = dead;
  detach() holds undriven; the Sweep example followed within 1.4 deg); 6 on the
  pop-up pages rendered; the demo project read back from disk (51 checks:
  devices, pins, wires, labels, no wire through a part, no wire crossing).

INSTALLATION (about 2 minutes)
1. Close Proteus. Extract the WHOLE ZIP to a normal folder (e.g. Desktop).
2. Copy everything in "Proteus Library Files" (TEPDS3218.LIB, and our Arduino
   library V4.0, ArduinoV4TEP.LIB, with the ARDUINO UNO V4.0 used by the demo)
   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).
3. Copy TEPDS3218.DLL and TEPARDUINO.DLL from "Proteus Model Files" to the
   MODELS folder (...\Proteus 8 Professional\MODELS).
   ArduinoV4TEP.LIB and TEPARDUINO.DLL are the files of our Arduino Library
   V4.0 - if you have it, they are the same.
4. Delete TEPDS3218.IDX from the LIBRARY folder if it is there (Proteus makes
   a new index).
5. Start Proteus. In Pick Devices (P) search "DS3218".

RUN THE DEMO
"Proteus Simulation\DS3218-Servo-Motor-ArduinoUnoV4.pdsprj" (an A4 sheet) -
keep the .hex file and the two DLLs beside the project.
  ARD1: Arduino UNO V4.0 running DS3218_Servo_Demo.hex (the Arduino Servo
        library), its serial monitor built in (window "TEP Arduino UNO - ARD1").
  SERVO1: the DS3218 - SIG on D9 (by the SIG net label), V+ on the +5V power
        terminal (Proteus' 5 V rail), GND.
  RV1: a 10k potentiometer (POT-HG) on A0 - the Knob example: turn it and the
        horn follows.
  1. Press Run. The monitor and the servo's pop-up open (move them aside -
     they open over the schematic). The horn goes to the pot's angle (RV1 at
     75 %: 135 deg = 2000 us).
  2. Type lib in the monitor and press Enter or Send, then 0 and 180: the horn
     stops at 4 and 171 deg - Servo.h's defaults. Type full and 180: 180 deg.
  3. On the pop-up pick 20 kg.cm and type 30: STALLED - more than the 19 kg.cm
     a DS3218 gives at 5 V. Pick 15 kg.cm: it moves, and holds a degree or two
     short. Click the horn for the 25 kg.cm brake (again to release).
  4. Try sweep, knob, us 2800 (beyond the range) and detach - see THE DEMO
     SKETCH; and the pop-up's Graphs, Event log and Check.
Closed a window? The monitor: click the UNO's USB port; the pop-up: OPEN PANEL.

WIRING (the same in Proteus and on a real board)
  DS3218 wire      Arduino UNO
   brown (GND)    GND (and the servo supply's minus)
   red (V+)       a 5 - 6.8 V supply of 4 A or more - NOT the Arduino's 5V
   orange (SIG)   D9 (any digital pin: the Servo library makes the pulses
                  with Timer1)
  Potentiometer   the ends to 5V and GND, the wiper to A0
In the sketch (Arduino Servo library, installed with the Arduino IDE):
  #include <Servo.h>
  Servo servo;
  servo.attach(9, 500, 2500);      // D9: 50 Hz pulses, 0 - 180 deg = 500 - 2500 us
  servo.write(90);                 // 1500 us
  servo.writeMicroseconds(1500);   // or the pulse itself
REAL HARDWARE:
 * A DS3218 draws up to 3 - 4 A when it starts or stalls: give it its own
   5 - 6.8 V supply (a 2S LiPo through a 6 V regulator, or a 6 V 5 A adapter),
   GND common with the Arduino. On the Arduino's 5V it resets the board.
 * Use attach(pin, 500, 2500): with attach(pin) the horn never reaches 0 or 180.
 * Some DS3218s are the 270 deg version: the same 500 - 2500 us cover 270 deg.
   Set PULSE_MIN / PULSE_MAX to your servo's range (the model is the 180 deg
   one).
 * analogWrite() is not a servo signal (980 Hz PWM): use the Servo library.

THE DEMO SKETCH ON THE SERIAL MONITOR (DS3218_Servo_Demo V1.0, 9600 baud)
  0 - 180       go to that angle and stay (the pot is ignored until knob)
  us 1500       writeMicroseconds(1500), 400 - 2900 us - try 2800: beyond the
                servo's range, the horn hits its end stop (the Servo library
                clamps writeMicroseconds() to the attach() limits, so the
                sketch re-attaches with attach(9, 400, 2900) for a pulse
                outside them)
  sweep         0 -> 180 -> 0 deg, 1 deg every 15 ms (the Sweep example),
                then back to the pot
  knob          follow the pot on A0 again (the Knob example)
  lib           attach(9): the Servo library's 544 - 2400 us (4 - 171 deg here)
  full          attach(9, 500, 2500): the DS3218's 0 - 180 deg (the default)
  detach        stop the pulses - the horn is no longer driven
  help          the list
EXPECTED MONITOR OUTPUT
  DS3218 Servo Motor demo - The Engineering Projects
  attach(9, 500, 2500): the DS3218's 0 - 180 deg
  Turn the pot on A0, or type an angle.
  Commands: 0-180 = angle, us 1500 = pulse width, sweep, knob, lib, full, detach, help
  Pot 768 -> Angle 135 deg -> pulse 2000 us

PROPERTIES (double-click the part > Edit Properties)
  PULSE_MIN   the pulse for 0 deg in us (default 500, the DS3218's)
  PULSE_MAX   the pulse for 180 deg in us (default 2500)
  START       the horn's angle at the start in deg (default 90)
  LOAD        a constant load on the horn in kg.cm (default 0; the DS3218 gives
              19 kg.cm at 5 V, 21.5 kg.cm at 6.8 V)
Every run starts again from the properties. The demo's UNO (ARDUINO UNO V4.0):
PROGRAM DS3218_Servo_Demo.hex, MONITOR YES (the built-in monitor), BAUD 9600,
AUTOOPEN YES, BOOTLOADER YES.

LINKS.INI (OPTIONAL)
The Help page cards of the pop-up open web pages. To point them somewhere else
without a new DLL, put a text file named links.ini next to TEPDS3218.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
* The horn never reaches 0 or 180 deg: the sketch uses attach(pin) - use
  attach(pin, 500, 2500), or set PULSE_MIN / PULSE_MAX to 544 / 2400.
* The horn never moves and the pop-up says NO POWER: V+ is not connected or
  below 3 V (a DS3218 wants 4.8 - 6.8 V).
* WAITING FOR PULSES / no pulses: SIG is on another pin than the sketch's
  attach(), or the sketch never called attach() / write().
* "SIG stays HIGH" or "pulses under 300 us": digitalWrite() or analogWrite() on
  the SIG pin - use the Servo library.
* The horn stops a degree or two short: a load it can carry - HOLDING AGAINST
  A LOAD. Under load a real servo droops too.
* STALLED: the load is above the torque at this supply (19 kg.cm at 5 V), or the
  brake - the orange ring round the hub.
* The part is not simulated / the horn never turns: TEPDS3218.DLL is missing
  from MODELS and from the project folder. No UNO / no monitor window:
  TEPARDUINO.DLL is missing, or click the UNO's USB port.
* The pop-up does not appear: click OPEN PANEL on the strip, or turn "Open the
  panel at Run" on its Settings page back on.

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot, the Serial Monitor text, the
simulation log and the pop-up's Copy diagnostics text:
  https://www.theengineeringprojects.com/forum/category/motor-driver-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 servo model (TEPDS3218.DLL), the symbol and artwork and the Arduino
  Library V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL, with its built-in TEP Serial
  Monitor Advance) are made by The Engineering Projects. The model is an
  independent implementation written from the typical data of the DS3218
  servo. The model uses only standard Windows libraries; no Visual C++
  redistributable is needed.
  The C++ source code is not included.
* Arduino UNO V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL, our Arduino Library
  V4.0 - its microcontroller is Proteus's own AVR model): The Engineering
  Projects, https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
* The potentiometer is Proteus's own POT-HG.
* The demo sketch uses the Arduino Servo library 1.2.2 (LGPL 2.1, Arduino:
  https://github.com/arduino-libraries/Servo), installed with the Arduino IDE.
  The .hex file is built from the demo sketch, the Servo library and the
  Arduino AVR core 1.8.6, which include LGPL-licensed code; their source code
  is available at https://github.com/arduino-libraries/Servo/tree/1.2.2 and
  https://github.com/arduino/ArduinoCore-avr/tree/1.8.6
* Proteus is a product of Labcenter Electronics and is not included. Arduino is
  a trademark of Arduino SA. DS3218 is a DSSERVO product.
  This library is not made or endorsed by DSSERVO, Arduino or Labcenter.

REBUILDING THE FIRMWARE (OPTIONAL)
The HEX file is supplied; Arduino IDE is not needed to run the demo. To edit the
sketch, open Arduino Code\DS3218_Servo_Demo\DS3218_Servo_Demo.ino (the Servo
library comes with the Arduino IDE), select Arduino Uno and use Sketch > Export
Compiled Binary. Replace the simulation's .hex with the exported HEX. The
sketch needs 6,938 bytes of flash (21 % of the UNO) and 319 bytes of RAM.

MODEL SCOPE AND LIMITS
Modelled: the DS3218's pulse decoding (300 - 3000 us, 50 - 333 Hz), the drive
while pulses come (about 22 ms after each pulse), the position loop with its
dead band, the motor (resistance, back-EMF), the driver's current limit, the
metal gearbox, inertia, friction, end stops, the current from V+, the torque
and the speed from the supply (4.8 - 6.8 V; 3 V and less: nothing moves), a
load torque, the droop under a load, stalls.
How it runs: Proteus runs the digital side (the Arduino's pulses) before each
analog step; the servo keeps every SIG edge with its time and integrates its
motor and horn over each step from that history, in 50 us steps, with analog
steps of 1 ms or less.
Not modelled: the digital servo's programmable options (its own range, speed,
fail-safe), the variations from part to part, gear play, heating and damage
from a wrong supply (the model only warns). The 270 deg DS3218 and continuous
rotation servos are other parts - the DS3218 here is the 180 deg servo.

VERSION
TEP DS3218 Servo Motor library V1.0 (Oct 2026). Device DS3218SERVOTEP
(TEPDS3218.LIB / TEPDS3218.DLL). Demo sketch DS3218_Servo_Demo V1.0 (Arduino
Servo library 1.2.2). Demo board: ARDUINO UNO V4.0 (TEP Arduino Library V4.0)
with its built-in serial monitor.