Project Files of NEMA 17 Closed-Loop Stepper Library for Proteus Simulation

NEMA 17 CLOSED-LOOP STEPPER LIBRARY FOR PROTEUS SIMULATION - V1.0 (an encoder-driven stepper, with a pop-up)
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/2026/11/nema-17-closed-loop-stepper-library-for-proteus.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
NEMA-17-Closed-Loop-Stepper-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                              201.9 KB   TEP Arduino boards V4.0 (UNO) -> LIBRARY
|   |-- TEPNEMA17CL.LIB                                16.8 KB   the library -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                883.5 KB   the Arduino board model -> MODELS folder
|   |-- TEPNEMA17CL.DLL                               315.0 KB   the model -> MODELS folder
|-- Proteus Simulation/
|   |-- ClosedLoop_Demo.hex                            22.8 KB   the demo firmware
|   |-- NEMA17CL-ArduinoUnoV4.pdsprj                   19.4 KB   the demo project
|   |-- TEPARDUINO.DLL                                883.5 KB   copy of the board model
|   |-- TEPNEMA17CL.DLL                               315.0 KB   copy of the model
|-- Arduino Code/
|   |-- ClosedLoop_Demo/ClosedLoop_Demo.ino             5.9 KB   the demo sketch (source of the .hex)
|-- README.txt                                        ~15.1 KB   this file
Total: 2.62 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
A NEMA 17 closed-loop stepper - a 42 mm stepper with a driver board on its back that reads the shaft
with a magnetic encoder - drawn
at true scale (the back: the 42 mm motor's end, the black board with its four mounting rings 31 mm
apart, the motor connector, the OLED, the
Next / Enter / Menu keys, the LED and the green terminal V+ GND COM EN STP DIR; our own drawing of
the open-source class of these boards, no
maker's mark):
  * The motor: the common 17HS4401 class - 1.8 deg, 1.7 A, 1.5 ohm, 2.8 mH, 0.40 N.m holding with
    both coils at 1.7 A, 50 rotor teeth, a
    detent of 2.2 N.cm, a 54 g.cm2 rotor.
  * The driver (this class of boards): 7 - 28 V, 0 - 3000 mA, 1 - 256 microsteps, a 14-bit magnetic
    encoder, field-oriented control, an
    OLED showing the shaft angle, the error and the pulses received; opto inputs STP / DIR / EN (3.3
    - 28 V above COM).
  * CR_vFOC (closed loop): the driver compares the encoder with the pulses it has received and sets
    the current from the error - a small
    current to hold, up to 3 A against a load; the field always 90 electrical degrees ahead of the
    rotor. A heavy load makes it lag, then
    catch up: it cannot lose steps. CR_OPEN: an ordinary stepper at the MA current - past 90
    electrical degrees of lag it slips 4 full steps.
  * PROTECT: in closed loop, a blocked shaft switches the motor off ("Wrong Protect" on the OLED);
    EN off, then on, restarts it.
  * Click it at Run for the pop-up: the shaft against the target on a dial, the error and the
    current over 2 s, the torque against the
    speed (closed loop, open loop, the load, the working point), graphs, an event log and a check
    page.
The body is drawn as on the real part and to true scale against our Arduino.
The TEP signature and the pop-up are TEP additions.

ONE DEVICE (search "NEMA17CL" in Pick Devices):
  NEMA17CLTEP  "NEMA 17 Closed-Loop Stepper V1.0" in TEPNEMA17CL.LIB (Electromechanical > Motors),
  prefix M, model TEPNEMA17CL.DLL (mixed).
               Pins V+, GND, COM, EN, STP, DIR on the right (the terminal). The name starts with N
               so that it sorts after the embedded
               ARDUINO UNO V4.0.

THE POP-UP
Click the part at Run. Tabs:
    Motor      the shaft (blue) against the target (orange) on a dial with the rotor's 50 teeth, a
    scope of the error and the current over
               2 s, the torque against the speed (closed loop up to 3 A, open loop at MA, the load,
               the working point), and eight live
               values: the shaft, the target and the pulses, the error (and the steps lost in open
               loop), the speed and the pulse rate, the
               current and its limit, the torque and the load, the supply, the mode. The chips on
               top: no load, 0.1 N.m, 0.3 N.m, blocked.
    Graphs     the live values over the last 2, 6 or 15 s. Live / Freeze.
    Event log  every change and warning; filters All / Changes / Warnings, Pause, Clear
    Check      what the part is doing and what to look at, 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 8 Nov 2026 (the demo project as shipped: an A4 sheet, an Arduino UNO V4.0).
What the runs showed (the model's own numbers and the sketch's monitor):
  * The project loads and starts cleanly; the 10 s program runs in about four minutes on our PC
    (with both pop-ups open).
  * Both motors on one STP / DIR / EN bus at 16 microsteps, 12 V: M1 closed loop (CR_vFOC), M2 open
    loop (CR_OPEN, 1200 mA). One turn at
    120 RPM: M1 0.11 deg off its target on 0.03 A, M2 0.08 deg off on its full 1.20 A. Three turns
    back at 300 RPM (16.2 kHz): M1 0.10 deg off,
    0.01 A; both hold exactly on -720.0 deg after it.
  * Running at 120 RPM, 0.3 N.m on both (the pop-ups' chips): M1 OFF TARGET 6.3 deg for 20 ms, then
    120 RPM with 1.82 A, 305 mN.m, 0.01 deg
    off; M2 SLIPPING - stalled, 200 full steps lost at 5.4 s, 640 (1153.7 deg) at 6.5 s.
  * The load off: M1 on target (0.08 deg, 0.04 A); M2 running again at 120 RPM but 640 full steps
    (1151.9 deg) behind for good. Stopped: M1 at
    2873.0 deg (0.11 deg off), M2 at 1721.1 deg (1152.1 deg short). EN high: both free.
  * The pop-up: Motor (the dial, the error and current scope, the torque against the speed), Graphs,
    Event log, Check - all four followed the
    run for both motors; the OLED showed the angle, the error and the pulses on the sheet.

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" (TEPNEMA17CL.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
   (use the folder that already holds Proteus's own .LIB files).
3. Copy TEPNEMA17CL.DLL and TEPARDUINO.DLL from "Proteus Model Files" to the MODELS folder
(...\Proteus 8 Professional\MODELS).
4. Delete TEPNEMA17CL.IDX from the LIBRARY folder if it is there (Proteus makes a new index).
5. Start Proteus. In Pick Devices (P) search "NEMA17CL".

RUN THE DEMO
"Proteus Simulation\NEMA17CL-ArduinoUnoV4.pdsprj" (an A4 sheet) - keep the .hex file and the DLLs
beside the project.
  ARD1:   Arduino UNO V4.0 running ClosedLoop_Demo.hex, its serial monitor built in (window "TEP
  Arduino UNO - ARD1").
  M1:     NEMA 17 closed-loop stepper, MODE CR_vFOC (closed loop).
  M2:     NEMA 17 closed-loop stepper, MODE CR_OPEN, MA 1200 (open loop) - on the same wires.
  Both:   V+ on +12V, GND and COM on GND, EN = D5 (low enables), STP = D6, DIR = D7; 16 microsteps
  (3200 pulses a turn).
  1. EN low, one turn forward at 120 RPM, one turn back at 300 RPM (Timer1 makes the pulses, with a
  ramp).
  2. Running forward at 120 RPM, a 0.3 N.m load is put on both motors from their pop-ups, then taken
  off; stop; EN high.
Closed the monitor? Click the UNO's USB port.

WIRING (the same in Proteus and on a real board)
  V+ / GND: 7 - 28 V (12 V or 24 V supplies; the motor runs faster on 24 V). COM to the controller's
  GND (the opto inputs' common).
  EN, STP, DIR to any outputs (3.3 - 28 V). The motor's own A+ A- B+ B- come wired from the board;
  the real board needs a calibration
  (CAL in its menu) the first time it is fitted to a motor.
REAL HARDWARE:
 * Calibrate first: the real board learns the encoder's offset with the motor unloaded (CAL); swap
   two motor wires if it jitters.
 * Closed loop needs current in reserve: the 3 A limit and the supply voltage set how much load it
   can carry at speed.
 * PROTECT is off by default: with it off, a blocked closed-loop motor keeps pushing up to 3 A (it
   gets hot).

THE DEMO SKETCH ON THE SERIAL MONITOR (ClosedLoop_Demo V1.0, 9600 baud)
The sketch runs its program, then waits. Type a command:
  m 1600   move 1600 pulses (half a turn)   v 200   run at 200 RPM   s   stop   e 0 / e 1   EN high
  / low
EXPECTED MONITOR OUTPUT
  NEMA 17 closed-loop stepper - The Engineering Projects
  M1 closed loop (CR_vFOC), M2 open loop (CR_OPEN), 3200 pulses a turn
  t=0.2 s: EN low: both motors enabled

PROPERTIES (double-click the part > Edit Properties)
  Mode (MODE)                          CR_vFOC (closed loop) or CR_OPEN (open loop)
  Open-loop current (MA)               mA in CR_OPEN (1200; closed loop sets its own current, up to
  3000 mA)
  Microsteps (MSTEP)                   1 - 256 (16)
  EN pin (EN)                          L (low enables), H (high enables), Hold (always enabled) (L)
  Direction (DIR)                      CW or CCW, the positive direction (CW)
  Stall protection (PROTECT)           Disable or Enable (Disable)
  Load (LOAD)                          the load on the shaft, N.m (0; the pop-up's chips change it
  at Run)
  Inertia (INERTIA)                    extra inertia on the shaft, g.cm2 (20; the rotor's own 54
  g.cm2 is always in)
Every run starts again from the properties.

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 TEPNEMA17CL.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
* It does not move: EN is not active (EN L needs EN low), or no pulses reach STP, or V+ is under 7
  V.
* OFF TARGET in closed loop: the load needs more than the current limit gives at this speed - lower
  the load or the speed, or raise V+.
* SLIPPING in open loop: the load is over the holding torque of the MA current - use closed loop, or
  raise MA.
* PROTECT: the shaft was blocked - free it, then set EN off and on.
* The part is not simulated: TEPNEMA17CL.DLL is missing from MODELS and from the project folder.
* The part is not simulated: TEPNEMA17CL.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.

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 model (TEPNEMA17CL.DLL), the symbols and artwork, the other parts of ours in the demo 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 models use 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 .hex file is built from the demo sketch and the Arduino AVR core 1.8.6, which includes
  LGPL-licensed code; its source code is available at
  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.
  This library is not made or endorsed by 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\ClosedLoop_Demo\ClosedLoop_Demo.ino, select Arduino Uno and use Sketch > Export
Compiled Binary. Replace the simulation's .hex with the exported HEX. The sketch needs 8,278 bytes
of flash and 480 bytes of RAM.

MODEL SCOPE AND LIMITS
Modelled: the pulses and the microsteps, the encoder loop (PID, 80 Hz - our tuning) with the 3 A
limit and the back-EMF against the
supply, the open-loop field with its slips, the detent, the shaft's friction, load and inertia,
PROTECT, the supply current, the motor's
temperature (lumped - our figures).
Not modelled: the UART mode and the menu keys, the calibration, the encoder's own error, the coils'
current ripple.

VERSION
TEP NEMA 17 Closed-Loop Stepper library V1.0 (Nov 2026). Device NEMA17CLTEP (TEPNEMA17CL.LIB /
TEPNEMA17CL.DLL). Demo sketch ClosedLoop_Demo V1.0. Demo board: ARDUINO UNO V4.0 (TEP Arduino
Library V4.0) with its built-in serial monitor.