Project Files of Trimmer Potentiometer Library for Proteus: 3296 and 3362

TRIMMER POTENTIOMETER LIBRARY FOR PROTEUS - V1.0 (real 3296 and 3362 trimmers you turn at Run, 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/trimmer-potentiometer-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/trimmer-potentiometer-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
The demo's LCD is our LCD 16x2 V3.0 (included):
  https://www.theengineeringprojects.com/2026/10/lcd-16x2-library-for-proteus-v3-0.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
Trimmer-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                              201.9 KB   TEP Arduino boards V4.0 (UNO) -> LIBRARY
|   |-- TEPLCD16X2.LIB                                137.8 KB   a part the demo uses -> LIBRARY folder
|   |-- TEPTRIM.LIB                                   133.2 KB   the library -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                883.5 KB   the Arduino board model -> MODELS folder
|   |-- TEPLCD.DLL                                    409.0 KB   its model -> MODELS folder
|   |-- TEPTRIM.DLL                                   311.0 KB   the model -> MODELS folder
|-- Proteus Simulation/
|   |-- LCD_Contrast_Demo.hex                          23.4 KB   the demo firmware
|   |-- TEPARDUINO.DLL                                883.5 KB   copy of the board model
|   |-- TEPLCD.DLL                                    409.0 KB   copy of its model
|   |-- TEPTRIM.DLL                                   311.0 KB   copy of the model
|   |-- Trimmer-LCD-Contrast-ArduinoUnoV4.pdsprj       26.4 KB   the demo project
|-- Arduino Code/
|   |-- LCD_Contrast_Demo/LCD_Contrast_Demo.ino         2.1 KB   the demo sketch (source of the .hex)
|-- README.txt                                        ~13.3 KB   this file
Total: 3.66 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
Cermet trimmer potentiometers, drawn at true scale and seen from the top. Two kinds:
  * 3296 (Bourns 3296W style): a blue box 9.53 x 4.83 mm with a brass screw at one end. 25 turns
    from end to end, 0.5 W.
  * 3362 (Bourns 3362P style): a blue 1/4 inch square with a cream rotor and a red index dot. 240
    degrees, 0.5 W.
  * Three pins in a line, 2.54 mm apart: 1 and 3 the ends of the track, W (2) the wiper.
  * At Run, click the 3296's box: the left half turns the screw back one turn, the right half on one
    turn. Click the 3362's rotor where its dot
    should point. The setting stays after Stop.
  * Used as a variable resistor, only part of the track carries the current and may take only that
    part of the rating. Too much burns it open.
  * The small dot opens the pop-up: the screw or the rotor, the track with both halves, eight live
    values, 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.

TWO DEVICES (search "TRIMMER" in Pick Devices):
  TRIMMER3296TEP   "Trimmer 3296 (25 turns) V1.0" in TEPTRIM.LIB (Resistors > Variable), prefix RV,
  model TEPTRIM.DLL. Pins 1, W (2), 3.
  TRIMMER3362TEP   "Trimmer 3362 (single turn) V1.0" in TEPTRIM.LIB (Resistors > Variable), prefix
  RV, model TEPTRIM.DLL. Pins 1, W (2), 3.

THE POP-UP
Click the small dot on the part at Run (a click on the box or the rotor turns it). Tabs:
    Trimmer    the use (VOLTAGE DIVIDER, VARIABLE RESISTOR, OVERLOAD, BURNT), the screw with its 25
    turns or the rotor on its scale, the track
               from pin 1 to pin 3 with the wiper, and eight live values. The toolbar: -10 %, -1 %,
               +1 %, +10 %, 0 %, 50 %, 100 %, Sweep, New part.
    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 31 Oct 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; RV1 (3296) starts at 50 % (12.5 turns) and RV2 (3362) at
    30 %, where Wiper while stopped puts them.
  * At the start RV1's wiper fed 2.47 V into the LCD's V0: the text was faint, and the LCD and the
    monitor said FAINT. RV2 read 1.51 V.
  * Four clicks on -10 % (ten turns of the screw) brought V0 down to 0.51 V: the text turned crisp
    white, GOOD. At 0 % (0.01 V) the dot blocks behind the text showed, DARK.
  * Back at 10 %, two clicks on RV2's +10 % moved its reading to 2.00 V and 2.50 V, shown on the
    LCD.
  * Real (guarded) mouse clicks: the right half of RV1's box turned the screw on one turn (50 % to
    54 %, 2.66 V); a click left of RV2's rotor pointed it at 9 o'clock (13 %, 0.66 V).
  * The pop-up: Trimmer, Graphs, Event log, Check - all four pages followed the run.

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" (TEPTRIM.LIB, TEPLCD16X2.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 TEPTRIM.DLL, TEPLCD.DLL and TEPARDUINO.DLL from "Proteus Model Files" to the MODELS folder
(...\Proteus 8 Professional\MODELS).
4. Delete TEPTRIM.IDX from the LIBRARY folder if it is there (Proteus makes a new index).
5. Start Proteus. In Pick Devices (P) search "TRIMMER".

RUN THE DEMO
"Proteus Simulation\Trimmer-LCD-Contrast-ArduinoUnoV4.pdsprj" (an A4 sheet) - keep the .hex file and
the DLLs beside the project.
  ARD1:   Arduino UNO V4.0 running LCD_Contrast_Demo.hex, its serial monitor built in (window "TEP
  Arduino UNO - ARD1").
  LCD1:   our LCD 16x2 V3.0 (blue, Advance): RS D2, E D3, D4 .. D7 to D4 .. D7; VSS, RW, K to GND;
  VDD, A to +5V.
  RV1:    a 3296 trimmer, 10k, set to 50 %: pin 1 GND, pin 3 +5V, the wiper to the LCD's V0, and to
  A1 so the sketch can show it.
  RV2:    a 3362 trimmer, 10k, set to 30 %: the same wiring, the wiper to A0. A setting for the LCD
  to show.
  1. Press Run. The LCD's text is faint: V0 sits at about 2.5 V.
  2. Turn RV1 down about ten turns (click the left half of its box, or its dot and -10 %). At about
  0.5 V the text is crisp.
  3. Turn it to 0 %: the dots behind the text show. That is too much contrast.
Closed the monitor? Click the UNO's USB port.

WIRING (the same in Proteus and on a real board)
  pin 1 - GND ; pin 3 - +5V ; wiper - the LCD's V0 : the contrast of a character LCD
  pin 1 - the circuit ; wiper - the circuit ; pin 3 free : a variable resistor, to set a current or
  a gain
REAL HARDWARE:
 * A trimmer is set once, while the circuit is calibrated: it is made for a few hundred adjustments,
   not for daily use.
 * The 3296's screw has a clutch at both ends: it slips instead of breaking, so count the turns.
 * Use a small insulated screwdriver; a metal one can short the wiper to something next to it.
 * For a character LCD, 10k is the usual value; good contrast is about 0.4 .. 1.2 V on V0.

THE DEMO SKETCH ON THE SERIAL MONITOR (LCD_Contrast_Demo V1.0, 9600 baud)
There are no commands. The sketch uses Arduino's LiquidCrystal library (it comes with the Arduino
IDE). It shows RV2 and V0 on the LCD,
and prints a line when either moves, at most twice a second.
EXPECTED MONITOR OUTPUT
  Trimmer: LCD contrast - The Engineering Projects
  RV2 1.51 V, V0 2.47 V - contrast FAINT
  RV2 1.51 V, V0 0.51 V - contrast GOOD

PROPERTIES (double-click the part > Edit Properties)
  Resistance (VALUE)       10k (1k, 2k, 5k, 10k, 20k, 50k, 100k ... like the real ones)
  Power rating, W          0.5, for the whole track
  Wiper while stopped      0 % .. 100 % by 5 %: where the wiper starts
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 TEPTRIM.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 LCD is blank or faint: V0 is too high. Turn RV1 down (the left half of its box).
* The LCD shows dark boxes: V0 is too low. Turn RV1 up a little.
* A click does nothing: the simulation is not running, or the click landed on the dot, which opens
  the pop-up.
* The track burnt: it was a variable resistor with too much current. Click New part, and add a
  series resistor.
* The part is not simulated: TEPTRIM.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/trimmer-potentiometer-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 (TEPTRIM.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
* The demo sketch also uses Arduino's LiquidCrystal library 1.0.7 (LGPL 2.1), compiled into the .hex
  file; its source code is available at https://github.com/arduino-libraries/LiquidCrystal
* 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\LCD_Contrast_Demo\LCD_Contrast_Demo.ino, select Arduino Uno and use Sketch > Export
Compiled Binary. Replace the simulation's .hex with the exported HEX. The sketch needs 8,496 bytes
of flash and 299 bytes of RAM.

MODEL SCOPE AND LIMITS
Modelled: the track and wiper, the end resistance, the derated power of a part of the track, the
heating and the burn-out; 25 turns or 240 degrees.
Not modelled: the tolerance spread (about 10 %), the temperature coefficient, the clutch's feel,
wear after a few hundred turns.

VERSION
TEP Trimmer library V1.0 (Nov 2026). Devices TRIMMER3296TEP and TRIMMER3362TEP (TEPTRIM.LIB /
TEPTRIM.DLL). Demo sketch LCD_Contrast_Demo V1.0. Demo board: ARDUINO UNO V4.0 (TEP Arduino Library
V4.0) with its built-in serial monitor.