Project Files of XIAO nRF52840 Sense Library for Proteus: Bluetooth, IMU, Fall Alarm

XIAO nRF52840 SENSE LIBRARY FOR PROTEUS - V1.0 (YOUR SKETCH WITH BLUETOOTH LE AND THE BOARD'S MOTION SENSOR)
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/xiao-nrf52840-sense-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/xiao-nrf52840-sense-proteus-library
The demo's other parts are our libraries (included) - their articles:
  https://www.theengineeringprojects.com/2026/10/oled-ssd1306-library-for-proteus-v1-0.html
  https://www.theengineeringprojects.com/2026/10/mobile-wifi-monitor-library-for-proteus.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
XIAO-nRF52840-Sense-TEP-v1.0/
|-- Proteus Library Files/
|   |-- TEPLAPTOP.LIB                                    39.5 KB   the laptop (demo), to LIBRARY
|   |-- TEPMOBILE.LIB                                    13.1 KB   the phone (demo), to LIBRARY
|   |-- TEPOLED12864.LIB                                112.4 KB   the OLED (demo), to LIBRARY
|   |-- TEPXIAOBLE.LIB                                   24.5 KB   the XIAO nRF52840 Sense, to LIBRARY
|-- Proteus Model Files/
|   |-- TEPNET.DLL                                       2.89 MB   the board + monitors + network, to MODELS
|   |-- TEPOLED.DLL                                     323.0 KB   the OLED, to MODELS
|-- Arduino Code/
|   |-- XIAO_Fall_Alarm/XIAO_Fall_Alarm.ino               7.8 KB   the demo sketch
|   |-- TEP Boards for Proteus/hardware/                 1.06 MB   the Arduino IDE add-on 1.56.0 (254 files)
|-- Proteus Simulation/
|   |-- TEPNET.DLL                                       2.89 MB   copy of the model
|   |-- TEPOLED.DLL                                     323.0 KB   copy of the model
|   |-- XIAO_Fall_Alarm.hex                              73.7 KB   the demo sketch (U1)
|   |-- XIAO-nRF52840-Sense-Fall-Alarm.pdsprj            17.7 KB   the demo: a fall alarm with an OLED and a phone
|-- README.txt                                          ~11.8 KB   this file
Total: 7.76 MB (unzipped). The source code of the models is not included.

WHAT IS IT?
Proteus 8 has no nRF52840 processor model, so this is NOT a real nRF52840 chip. Our team has put a lot of effort into
building this board ourselves: it is the Seeed Studio XIAO nRF52840 Sense - the 21 x 17.8 mm board with an LSM6DS3TR-C
motion sensor, an RGB LED and a USB-C port - that runs YOUR Arduino sketch in Proteus:
  * You write a normal sketch for the XIAO's pins (D0 .. D10, A0 .. A5, analogRead 0-1023, analogWrite,
    attachInterrupt, tone, Wire, SPI, Serial, Serial1) and compile it in the Arduino IDE with our board package "TEP
    Boards for Proteus" 1.56.0 (in Arduino Code - see INSTALLATION).
  * Bluetooth LE works: #include <ArduinoBLE.h>, services, characteristics, BLE.advertise(), BLE.central(), written(),
    writeValue() and descriptors, as on a real board. The central is our Mobile WiFi Monitor: its Bluetooth app lists
    what advertises, connects, shows every characteristic live and writes a value.
  * The motion sensor answers: #include <LSM6DS3.h>, LSM6DS3 imu(I2C_MODE, 0x6A), imu.begin(), readFloatAccelX .. Z,
    readFloatGyroX .. Z and readTempC, with the same calls as Seeed's library. The board's Sensors window sets the
    temperature, a tilt, a shake or a whole fall.
  * The RGB LED is on the board: LED_RED, LED_GREEN and LED_BLUE, lit when LOW. LED_BUILTIN is LED_RED.
TEP additions: the PANEL pad opens the Sensors window, the USB port opens the serial monitor (the same window as our
TEP Serial Monitor Advance).
Limits (say them before you start): this board is a Bluetooth peripheral: the central API (BLE.scan, BLE.available and
the remote classes) is not in this version. The microphone (PDM) and the on-board flash are NOT modelled.
Your sketch gets 8 KB of RAM in the simulation (the real one: 256 KB), about 256 KB of flash, and int is 16 bits in
the simulation (use long for big numbers). No Mbed OS, no threads. The sensor gives the Sensors window's values,
without noise. See MODEL SCOPE AND LIMITS.

ONE DEVICE (search "NRF52840" in Pick Devices):
  XIAO NRF52840 SENSE  "XIAO nRF52840 Sense" V1.0 (Microprocessor ICs > Bluetooth Boards), prefix U, model TEPNET.DLL.
  Two TEP windows, none with a Windows title bar:
  the Sensors window (the PANEL pad) and the serial monitor (the USB port, 115200 baud: Monitor, Plotter and Board
  tabs).
The same TEPNET.DLL also runs our other sketch boards and the phone; it replaces any older TEPNET.DLL (keep only this
newest one in MODELS).

TEST STATUS
V1.0: verified in Proteus 8.5 on 31 Oct 2026 with the demo project as shipped. What the Proteus run showed:
* XIAO-nRF52840-Sense-Fall-Alarm: "Advertising as TEP Pendant", every 2 s "Tilt 0 deg  23.5 C  falls 0", the OLED "ALL
  OK", the green LED.
* The phone's Bluetooth app listed TEP Pendant; Connect: ">> Phone connected", the blue LED, and the app showed all
  five characteristics live.
* The Sensors window: SHAKE ">> A bump: 3.0 g, no free fall: no alarm"; LEFT "Tilt 45 deg"; FALL, then FLAT in time:
  ">> Free fall", ">> Impact: 3.7 g", ">> Got up again: no alarm".
* FALL and staying down: ">> Free fall", ">> Impact: 3.4 g", ">> FALL! Alarm on": the red LED, "FALL!" on the OLED,
  Alarm true and Falls 1 on the phone.
* 0 written to the Alarm on the phone: ">> Phone: alarm cleared". 3 written to the Impact limit: ">> Phone: impact
  limit 3.0 g". Temperature +10: "33.5 C". Disconnect: ">> Phone left".
* about 55 s of simulation, no errors, with the Sensors window, the OLED's window, the phone and the monitor open.

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). TEPXIAOBLE.LIB is the board;
   the others are the demo's parts: TEPOLED12864.LIB, TEPMOBILE.LIB and TEPLAPTOP.LIB.
3. Copy the DLLs from "Proteus Model Files" (TEPNET.DLL, TEPOLED.DLL) to the MODELS folder (...\Proteus 8
   Professional\MODELS) -
   replace an older TEPNET.DLL (this one is the first that knows this board).
4. Delete TEPXIAOBLE.IDX from the LIBRARY folder if it is there.
5. The Arduino IDE (only to compile your own sketches - the demo has its HEX file): copy the folder
   "Arduino Code\TEP Boards for Proteus\hardware" into your sketchbook folder (normally Documents\Arduino), so that
   Documents\Arduino\hardware\tep\avr\boards.txt exists (replace an older copy); restart the IDE. The Arduino AVR Boards
   platform must be installed (it comes with IDE 1.8.x; in IDE 2.x install "Arduino AVR Boards" from the Boards
   Manager once).
   Tools > Board > TEP Boards for Proteus > XIAO nRF52840 Sense (TEP Proteus). ArduinoBLE and the LSM6DS3 library are
   in the board package. From the Library Manager: Adafruit SSD1306 and Adafruit GFX.
6. Start Proteus. In Pick Devices (P) search "NRF52840".

RUN THE DEMO
Keep the .hex file and the DLLs beside the project in "Proteus Simulation".
XIAO-nRF52840-Sense-Fall-Alarm.pdsprj - U1 the XIAO nRF52840 Sense (XIAO_Fall_Alarm.hex) is a wearable fall alarm:
OLED1 = the 0.96" SSD1306 OLED (Advance) on I2C (SDA D4, SCL D5), MOB1 = the phone (Mobile WiFi Monitor).
Press Run. The OLED says ALL OK, the LED is green, and the monitor prints the tilt every two seconds. On the phone
open the Bluetooth app and click Connect beside TEP Pendant: the LED turns blue and the values appear.
Click the PANEL pad for the Sensors window. SHAKE is a bump: no alarm. LEFT is leaning over: no alarm. FALL is a real
fall: free fall, an impact, then lying on one side. Three seconds later the alarm is on: the red LED, FALL! on the
OLED, Alarm true on the phone.
Click FLAT within the three seconds and the sketch says the wearer got up: no alarm. To clear an alarm, click the
phone's Alarm row, type 0 and press Send.
Closed a window? The USB port opens the monitor, the PANEL pad the Sensors window, a click on the phone's screen the
phone.

THE PINS (the label on the part, what it can do in the simulation)
  D0 .. D3        A0 .. A3: analogRead 0 .. 1023 for 0 .. 3.3 V, GPIO, PWM, interrupt
  D4, D5          Wire SDA, SCL (A4, A5), or GPIO
  D6, D7          Serial1 TX, RX, or GPIO
  D8, D9, D10     SPI SCK, MISO, MOSI, or GPIO
  3V3, 5V, GND    3.3 V (the logic), 5 V, ground
LED_BUILTIN is LED_RED. LED_RED, LED_GREEN and LED_BLUE are the RGB LED, lit when LOW. Serial is the USB: the board's
built-in monitor. RST on the board resets the sketch.

PROPERTIES (double-click the part > Edit Properties)
  PROGRAM      the sketch's HEX (Arduino IDE: Sketch > Export Compiled Binary with XIAO nRF52840 Sense (TEP Proteus))
  TEMPERATURE  the temperature at Run (C)
  MONITOR      YES = the built-in serial monitor on Serial;  BAUD  its speed (115200, or AUTO)
  AUTOOPEN     YES = the monitor window opens at Run (the demo: YES)

TROUBLESHOOTING
* The phone's list is empty: BLE.begin(), then BLE.advertise(). The phone needs this TEPNET.DLL or newer.
* written() is never true: call BLE.poll() in loop(), and give the characteristic BLEWrite.
* imu.begin() does not return 0: the board in Tools must be XIAO nRF52840 Sense (TEP Proteus).
* The OLED stays dark: SDA on D4, SCL on D5, the address 0x3C.
* The RGB LED looks inverted: it lights when the pin is LOW.
* An integer goes wrong above 32767: int is 16 bits in the simulation - use long.

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot and the Serial Monitor text:
  https://www.theengineeringprojects.com/forum/category/xiao-nrf52840-sense-proteus-library

LICENCES AND THIRD-PARTY NOTES
* The board model (TEPNET.DLL), the symbols and artwork (TEPXIAOBLE.LIB) and the OLED model are made by The
  Engineering Projects. The source code of the models is not included.
* TEP Boards for Proteus (Arduino Code): its core, the variants and the EEPROM, SPI and Wire libraries are modified
  copies of the Arduino AVR core 1.8.6 - GNU Lesser General Public License 2.1 (LGPL 2.1, the text:
  LICENSE-LGPL-2.1.txt); its WiFi, WebServer, ArduinoBLE, the sensor libraries and the others and our core files are
  MIT (LICENSE-MIT.txt).
* Our ArduinoBLE and LSM6DS3 have the calls of the libraries of those names by Arduino and Seeed Studio; their code is
  ours.
* The demo sketch uses Adafruit SSD1306 and Adafruit GFX (BSD): install them with the Library Manager to rebuild.
* Proteus is a product of Labcenter Electronics and is not included. XIAO is a name of Seeed Studio, and nRF52840 of
  Nordic Semiconductor. The Bluetooth word mark belongs to Bluetooth SIG. This library is not made or endorsed by them
  or by Labcenter.

REBUILDING THE FIRMWARE (OPTIONAL)
The HEX file is supplied. Install TEP Boards for Proteus (INSTALLATION step 5), open Arduino Code\XIAO_Fall_Alarm,
select XIAO nRF52840 Sense (TEP Proteus) and use Sketch > Export Compiled Binary. For a real board use Seeed's nRF52
board packages (their wiki says which to pick), and install ArduinoBLE and Seeed Arduino LSM6DS3. Its pins work at 3.3
V.

MODEL SCOPE AND LIMITS
Modelled: the XIAO's pins; digital I/O, analogRead 0 .. 1023, PWM (analogWrite), tone and attachInterrupt through the
board model; Serial (the board's monitor), Serial1, Wire and SPI; the RGB LED and the charge LED; Bluetooth LE as a
peripheral, with one central; the LSM6DS3 through the library above.
Not modelled: the nRF52840 itself, Mbed OS, the PDM microphone, the 2 MB on-board flash, the battery charger, the
Bluetooth central role, pairing and bonding, signal strength. The simulation runs below real time.

VERSION
TEP XIAO nRF52840 Sense library V1.0 (Nov 2026). Device XIAO NRF52840 SENSE (TEPXIAOBLE.LIB / TEPNET.DLL), TEP Boards
for Proteus 1.56.0 (adds this board and the LSM6DS3 library).
Demo sketch XIAO_Fall_Alarm V1.0. Demo parts: OLED12864BLUEADVTEP and MOBILE WIFI MONITOR.