Project Files of BME280 Sensor Library for Proteus V1.1 (I2C + SPI + Arduino)

BME280 SENSOR (TEMPERATURE / HUMIDITY / PRESSURE) LIBRARY FOR PROTEUS - V1.1
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/2026/09/bme280-sensor-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/bme280-proteus-library
The demo uses our TEP Serial Monitor Advance (included) instead of Proteus's
Virtual Terminal - its own article:
  https://www.theengineeringprojects.com/2026/10/serial-monitor-advance-proteus-library.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
BME280-TEP-v1.1/
|-- Proteus Library Files/
|   |-- ArduinoV3TEP.IDX                              0.8 KB   its index -> LIBRARY folder
|   |-- ArduinoV3TEP.LIB                             95.6 KB   TEP Arduino UNO (demo) -> LIBRARY folder
|   |-- TEPBME280.LIB                                89.4 KB   BME280 Simple + Advance (2 devices) -> LIBRARY folder
|   |-- TEPSERIALMON.LIB                             11.1 KB   TEP Serial Monitor Advance -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPBME280.DLL                               381.0 KB   BME280 model -> MODELS folder
|   |-- TEPSERIALMON.DLL                            978.0 KB   Serial Monitor model -> MODELS folder
|-- Proteus Simulation/
|   |-- BME280_Demo.hex                              65.0 KB   both UNOs (demo sketch v1.1)
|   |-- BME280-ArduinoUnoV3.pdsprj                   25.5 KB   demo: UNO 1 + Simple (0x76), UNO 2 + Advance (0x77)
|   |-- TEPBME280.DLL                               381.0 KB   copy of the model so the demo runs as is
|   |-- TEPSERIALMON.DLL                            978.0 KB   copy of the monitor model
|-- Arduino Code/
|   |-- BME280_Demo/BME280_Demo.ino                  11.5 KB   the demo sketch (source of its .hex)
|   |-- libraries/Adafruit_BME280_Library/           47.5 KB   Adafruit BME280 2.3.0 (BSD, LICENSE), 9 files
|   |-- libraries/Adafruit_Unified_Sensor/           36.5 KB   Adafruit Unified Sensor 1.1.15 (Apache 2.0), 5 files
|   |-- libraries/Adafruit_BusIO/                    53.6 KB   Adafruit BusIO 1.17.4 (MIT, LICENSE), 14 files
|-- README.txt                                      ~35.5 KB   this file
Total: 3.12 MB (unzipped). The C++ source code of the model is not included.

WHAT IS IT?
A simulation model of the Bosch BME280 temperature, humidity and pressure
sensor on the common purple GY-BME280 breakout board for Proteus 8. Your
Arduino talks to it exactly as to the real one - over I2C (address 0x76 or 0x77,
chosen by the SDO pin) or SPI (4-wire or 3-wire) - and the popular Adafruit
BME280 library runs unmodified: begin, setSampling (sleep / forced / normal
mode, oversampling x1 .. x16, the IIR filter, the standby time),
takeForcedMeasurement, readTemperature, readHumidity, readPressure,
readAltitude, seaLevelForAltitude, sensorID; Bosch's own BME280 SensorAPI runs
on it too. The model has the chip's registers, its factory trimming
(calibration) bytes, its measurement timing from the data sheet, normal mode
with the standby time, forced mode, the IIR filter, the 2 ms start-up and the
soft reset. You set the temperature, humidity and pressure with sliders or with
six weather presets. The part looks like the purple GY-BME280 board: the metal
BME280 with its vent hole, the "103" resistors and the capacitors, the mounting
hole and the 6-pin header; while the simulation runs the thermometer, the
humidity drop and the barometer needle follow the environment, the vent glows
cyan while the chip measures, and a weather window above the board shows the
weather (sun, clouds, rain, storm, snow, mountain) with the altitude. Beside the
title sit a red PWR LED and a green I2C LED - both are TEP additions (the real
GY-BME280 has no LED): PWR lights while VCC and GND are connected, I2C flashes
for every bus operation addressed to the chip.

TWO DEVICES IN ONE LIBRARY (search "BME280" in Pick Devices):
  BME280 Simple    device BME280TEP     "BME280 Environmental Sensor - Simple"
                   On-Sheet Panel: a weather panel on the schematic next to the
                   board - TEMPERATURE (-40 .. 85 C), HUMIDITY (0 .. 100 %) and
                   PRESSURE (300 .. 1100 hPa) sliders, the presets SUNNY,
                   RAINY, STORM, SNOW, MOUNTAIN and SEA LEVEL, and a status box:
                   the chip's settings (mode, oversampling, filter, rate), what
                   the Arduino read last, the bus (I2C 0x76 / 0x77 or SPI with
                   its measured clock), the altitude and the dew point. The red
                   X in the panel's header closes it, the PANEL button on the
                   board opens it again. Your v1.0 designs keep working with
                   this device.
  BME280 Advance   device BME280ADVTEP  "BME280 Environmental Sensor - Advance"
                   Pop-Up Panel: only the board on the schematic; at Run a TEP
                   pop-up window "TEP BME280 Advance" opens - the same look as
                   the TEP Serial Monitor (move it by its header, resize it,
                   minimise it). The tabs Weather and Test sit in the header;
                   the gear and ? icons open Settings and Help; the palette icon
                   switches the theme:
                     Weather   the SENSOR card (chip ID, address, mode,
                               oversampling, filter, standby, rate and
                               t_measure), a gauge card for temperature,
                               humidity and pressure (click the track or - / +,
                               with the value your Arduino read), the WEATHER
                               card (the weather, the altitude, the sea-level
                               pressure with -1 / +1 / 0 m here / 1013.25, the
                               dew point and the absolute humidity), the six
                               presets, the TREND of the last measurements (T /
                               H / P) and the last bus operations, decoded
                     Test      four tools measured on the model with your
                               sketch: Register check, Timing, Step response,
                               Altitude (see THE TEST TOOLS below)
                     Settings  theme (TEP Dark / Light), text size, open at Run,
                               window size - remembered for your Windows user
                     Help      Help & Support like the TEP Serial Monitor: report
                               a bug, suggest a feature, article, user guide,
                               updates, donate, website, forum; Copy diagnostics
                               (sensor, settings, registers, environment, bus,
                               test results) for a bug report
                   The OPEN PANEL button on the board opens the window again
                   after you close it.
Both devices use the same model (TEPBME280.DLL) and the same properties.

NEW IN V1.1
* Two devices: BME280 Simple (weather panel on the sheet, close / open) and
  BME280 Advance (pop-up window with gauges, presets, the weather, four test
  tools, settings and help) - see above.
* Board: the real purple GY-BME280's look - the metal BME280 with its vent hole,
  the 103 resistors, the caps, the mounting hole, the 6-pin header - with an
  animated thermometer, humidity drop and barometer needle, the values under
  them, a weather window above the board (the weather icon, the word and the
  altitude), the vent glowing cyan while a measurement runs, a PANEL / OPEN
  PANEL button and a SIMPLE / ADVANCE badge. LEDs: PWR (red) and I2C (green) -
  TEP additions (the real board has no LED): I2C lights for 150 ms (simulation
  time) after every bus operation addressed to the chip.
* Model - timing: a measurement takes the data sheet's typical time
  1 + 2 T + (2 P + 0.5) + (2 H + 0.5) ms (T, P, H = the oversampling: 8 ms at
  x1, 98 ms at x16; v1.0 used the maximum time); the status register's
  measuring bit is set while it runs. Normal mode measures, waits the standby
  time (0.5, 10, 20, 62.5, 125, 250, 500 or 1000 ms) and measures again - at
  x1 and 125 ms that is one measurement every 133 ms (7.52 Hz); forced mode
  measures once and goes back to sleep; sleep stops. The IIR filter (2, 4, 8,
  16) works on every measurement as in the data sheet: filter 16 reaches 75 %
  of a step after 22 measurements. The chip needs 2 ms after power-up (writes
  in that time are ignored), a soft reset (E0 = B6) restarts it.
* Model - interfaces: I2C at 0x76 (SDO low or open - the board's pull-down) or
  0x77 (SDO high); SPI when CSB is pulled LOW (4-wire, modes 00 and 11; 3-wire
  with config spi3w_en) - once CSB was low the chip stays in SPI until a power
  cycle or a soft reset, as the data sheet says. CSB open = I2C (the board's 10k
  pull-up). The chip ID 0x60 is read-only; ctrl_hum takes effect at the next
  ctrl_meas write; config writes in normal mode are ignored (and counted).
* Model - logs: every bus operation (I2C / SPI write, read, address probe, a
  NACK at the wrong address, decoded: "F4 = 27 ctrl_meas T x1 P x1 NORMAL",
  "I2C read temperature 16.00 C (raw 490930)"), every measurement (start, end,
  settings) and which measurement each read of your sketch returned - the
  Simple panel's status, the Advance Weather page and the test tools show them.
* Property SEALEVEL (default 1013.25 hPa): the sea-level pressure the board and
  the panels use for the altitude.
* The demo: ONE project with two UNOs - UNO 1 with BME280 Simple at 0x76, UNO 2
  with BME280 Advance at 0x77 (SDO to VCC) - each with the TEP Serial Monitor
  Advance instead of the Virtual Terminal (U3 = UNO 1, U4 = UNO 2, quick
  buttons) and a weather alert LED on A0.
* The demo sketch (v1.1) keeps every v1.0 line and adds: the address search
  (0x76, then 0x77), the weather alert LED (humidity 80 % and more = rain
  likely, 35 C and more = heat), and the Serial Monitor commands HELP, STATUS,
  READ, MODE, OSR, FILTER, STANDBY, RATE, SEALEVEL, ALTITUDE, ALT, DEFAULTS. It
  prints one reading a second, as v1.0 - no other periodic lines.
* Version 1.1 everywhere; the C++ source code is no longer included (and
  neither is the Arduino AVR core archive - its GitHub link is below).

TEST STATUS
v1.1: verified in Proteus 8.5 on 8 Oct 2026 (Proteus 8.5 SP0, this package's
demo run from a copy of "Proteus Simulation" with the package DLLs):
  Start-up: U3 found the sensor at 0x76, U4 at 0x77, chip ID 0x60, one reading
  a second; U2's pop-up opens with no system caption row.
  U1 (Simple): RAINY "Temperature: 16.0 C | Humidity: 92.0 % | Pressure: 1002.0
  hPa" and "Weather alert: humidity 92.0 % - rain likely (LED A0 on)" - LED D1
  lit, rain in the weather window; SUNNY "Weather alert over (LED A0 off)";
  MOUNTAIN 5.0 C, 40 %, 795.0 hPa; ALT: altitude 1999.9 m, dew point -7.5 C;
  STATUS; the red X closes the panel, PANEL opens it again.
  U4: OSR 16 "(t_measure 98.0 ms typical)", FILTER 16. U2 (Advance) Test page
  with OSR 16 + FILTER 16: Register check - SCL 100.0 kHz measured, D0 = 60
  read 1x, 1 soft reset, calibration 32 / 32, F2 = 05, ctrl_meas B7, config 50;
  Timing x10 - t_measure 98.000 ms, period 223.0 ms (4.48 Hz), the sketch read
  2 of 10; Step response (temperature +10 C, filter 16) - the chip at 50 %
  after 2340.8 ms / 11 samples, 90 % after 7916 ms / 36, 99 % after 15943.8 ms
  / 72, the sketch saw 90 % at 8813.1 ms; Altitude climb +100 m - 13 reads, max
  error 32.55 m, lag 2351 ms, not settled within the 3 s (the filter 16 lag).
  Settings, Help (all 8 cards with the live links), close the pop-up and OPEN
  PANEL.
  A v1.0 design (the v1.0 release demo) with the v1.1 TEPBME280.DLL: the v1.0
  panel (ENVIRONMENT CONTROLS) shows; the temperature slider moved to 59.3 C
  and the v1.0 sketch printed it ("Temperature: 59.3 C | Humidity: 50 ...").
  After that run the sketch's longer lines were shortened for the Serial
  Monitor's Simple interface (every line now 81 characters at most): HELP is
  two lines, STATUS four, ALT prints altitude and dew point as an indented line
  under each reading (the v1.0 reading line is unchanged), DEFAULTS one short
  line - tested on a PC (the demo sketch test), not re-run in Proteus.
  Not run in Proteus: SPI (tested on a PC only - no demo uses it).
PC tests (8 Oct 2026):
  3628 automatic checks on a PC, 0 failed, plus the unchanged v1.0 test: 67 on
  the chip model (the data sheet's timing table, start-up, forced / normal /
  sleep, the standby times, the IIR filter samples, SPI 4-wire / 3-wire, the
  logs, altitude and dew point, the four tools); 61 with real drivers - the 21
  v1.0 checks with Bosch's BME280 SensorAPI over bit-level I2C, unchanged, plus
  40 for v1.1 with the unmodified Adafruit BME280 2.3.0 library (both
  addresses, forced x1 done after 9.42 ms (the library polls every 1 ms),
  forced x16 98.74 ms, the eight standby periods, filter 16 = 22 samples to 75
  %, hardware and software SPI, the CSB latch) and Bosch's API over SPI 4-wire
  and 3-wire; 91 on the complete Proteus model (the 12 of v1.0 on a design with
  the v1.0 symbol plus both devices, the panel's sliders / presets / red X /
  PANEL, the pop-up and its pages, the board's LEDs / thermometer / drop /
  needle / weather window, SPI through the pins, power); 44 with the real
  demo sketch on two UNOs (every v1.0 output line, the address search, the LED,
  every Serial Monitor command, the three timed tools with the sketch, every
  line within 90 characters even with the longest values); 3365
  on the rendered boards and pop-up windows (every page fits in TEP Dark and
  Light, at Large text and 150 % DPI; every tool's hint lines fit the window;
  every header state fits).
v1.0 (Sep 2026): the v1.0 demo (one UNO, Virtual Terminal) was run in
  Proteus 8.5 SP0 - the three sliders against the serial readings.
Made for Proteus 8.5 SP0 and newer (Proteus 7 is not supported).

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" (TEPBME280.LIB with both devices,
   TEPSERIALMON.LIB and the TEP Arduino UNO V3 library ArduinoV3TEP.LIB / .IDX
   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 TEPBME280.DLL and TEPSERIALMON.DLL from "Proteus Model Files" to the
   MODELS folder (...\Proteus 8 Professional\MODELS).
4. Updating from v1.0: replace TEPBME280.LIB and TEPBME280.DLL, and delete
   TEPBME280.IDX if there is one in the LIBRARY folder. A v1.0 design keeps its
   v1.0 symbol: it runs with the new model and shows the v1.0 panel (without the
   v1.1 board parts and the red X) - re-pick the part to get the v1.1 symbol.
5. Start Proteus. In Pick Devices (P) search "BME280": you get the Simple and
   the Advance device (category Sensors > Environmental, as in v1.0).

RUN THE DEMO
"Proteus Simulation\BME280-ArduinoUnoV3.pdsprj" - keep BME280_Demo.hex and the
two DLLs beside the project.
  UNO 1 (ARD1): BME280 Simple (U1) at 0x76 (SDO and CSB open), Serial Monitor
                U3, BME280_Demo.hex.
  UNO 2 (ARD2): BME280 Advance (U2) at 0x77 (SDO to VCC, CSB open), Serial
                Monitor U4, the same BME280_Demo.hex (it finds the address).
  An LED (D1 / D2) with 220 ohm on A0 of each UNO: the weather alert LED.
  1. Press Run. Both monitor windows open (9600 baud) and so does U2's pop-up.
     U3 shows "TEP BME280 - Temperature / Humidity / Pressure", "Demo v1.1 -
     BME280 found at 0x76 (SDO low / open), chip ID 0x60", the command list,
     then one reading a second: "Temperature: 25.0 C | Humidity: 50.0 % |
     Pressure: 1013.2 hPa". U4 says "found at 0x77 (SDO high)". The PWR LEDs
     are lit, the I2C LEDs flash with every reading, the vents glow at 7.5 Hz.
  2. U1: drag a slider on the panel beside the board - the next reading line
     has the new value (the chip measures every 133 ms). Click RAINY: "Weather
     alert: humidity 92.0 % - rain likely (LED A0 on)", LED D1 lights, the
     weather window rains. SUNNY: "Weather alert over (LED A0 off)". MOUNTAIN:
     795 hPa = ALT 2000 m. Close the panel with its red X and open it with
     PANEL on the board.
  3. U3 / U4 quick buttons: STATUS (address, chip ID, mode, oversampling,
     filter, standby, t_measure and the last reading with altitude and dew
     point), OSR 16 (all three x16: t_measure 98.0 ms), FILTER 16 (the IIR
     filter - a slider change now creeps in over a few seconds), ALT (altitude
     and dew point on a line under every reading). Type HELP, MODE FORCED,
     STANDBY 1000, RATE 200, SEALEVEL 1000, ALTITUDE 100, DEFAULTS.
  4. U2 (Advance): Weather page - click a gauge's track or - / +, a preset, 0 m
     here (the altitude becomes 0 m at the pressure now). Test page:
       Register check: the chip ID read, 32 / 32 trimming bytes read, every
         setting your sketch wrote (decoded) and the bus operations.
       Timing: 5 / 10 / 20 measurements - t_measure 8.000 ms and a period of
         133.000 ms with the demo's settings; the sketch (one reading a second)
         reads about one in seven measurements.
       Step response: type FILTER 16 on U4 first, then step the temperature
         +10 C - the chip is at 90 % after 36 measurements (about 4.7 s; 7.9 s
         after OSR 16), the sketch prints it at its next reading.
       Altitude: a 100 m climb in 10 s - the altitude of each pressure your
         sketch read against the true one; with FILTER 16 the altitude lags.
  5. Close U2's window and open it again with OPEN PANEL on the board.
Closed a monitor window? Click OPEN MONITOR on the monitor part.

WIRING
I2C (both UNOs in the demo): VCC -> supply, GND -> GND, SCL -> A5, SDA -> A4.
  SDO open or GND = address 0x76, SDO -> VCC = 0x77. CSB open or VCC = I2C.
  In the sketch: Adafruit_BME280 bme;  bme.begin(0x76);  Serial 9600.
  The UNO's Wire library turns on its internal pull-ups; the simulation needs
  no external pull-up resistors (a real bus does - the board has them).
SPI (property-free - just wire it): CSB -> D10 (chip select), SCL = SCK -> D13,
  SDA = SDI -> D11 (MOSI), SDO -> D12 (MISO). In the sketch:
  Adafruit_BME280 bme(10);  bme.begin();  (or bme(10, 11, 12, 13) for software
  SPI). Once CSB was LOW the chip answers SPI only, until a power cycle.
  The weather alert LED + 220 ohm from A0 to GND on both UNOs.
  Serial Monitor RXD <- Arduino D1 (TX), Serial Monitor TXD -> Arduino D0 (RX),
  Serial Monitor GND -> ground. RXD2 is not needed: I2C has no serial line
  between the sensor and the Arduino to watch.
Pin order in Proteus: VCC GND SCL SDA SDO CSB (v1.0). On the real GY-BME280
the header reads VCC GND SCL SDA CSB SDO - SDO and CSB are swapped against the
Proteus part: wire by the names.
REAL HARDWARE:
 * Supply: the 6-pin purple GY-BME280 (often sold as GY-BME280-3.3) has no
   regulator - VCC 3.3 V (the UNO's 3.3V pin), NOT 5 V. Some other BME280
   boards have a regulator and take 5 V: check yours.
 * Logic levels: the BME280 is a 3.3 V chip. On I2C the board's pull-ups go
   to 3.3 V and the UNO reads that as HIGH; for SPI from a 5 V UNO use a
   level shifter on CSB, SCK and SDI.
 * The board pulls CSB up (10k): leave it open for I2C. SDO sets the address
   LSB: GND = 0x76, 3.3 V = 0x77 (some boards pull SDO up and answer at 0x77 -
   the demo sketch tries both).
 * A BMP280 (no humidity) looks the same and has chip ID 0x58: the Adafruit
   BME280 library refuses it. The model is always a BME280 (0x60).
 * The real sensor warms itself a little in normal mode with high
   oversampling; the simulation has no self-heating, noise or drift.

THE TEST TOOLS (BME280 Advance, Test tab) - what they really measure
Every tool runs on the live model with your sketch. A tool only changes the
environment and reads the BME280's own logs - it never talks to your Arduino -
so every time is what the chip and your sketch's reads really did, measured with
the simulation clock. Each tool shows one "Good for:" line and one line on how
it measures.
  Register check  Good for: checking that your sketch found the chip, read all
                  its trimming bytes and set what it wanted. The chip ID read,
                  the 32 trimming (calibration) bytes the compensation needs
                  (read / not read, with the values), the registers ctrl_hum,
                  status, ctrl_meas and config decoded, the writes the BME280
                  ignored and why (config in normal mode, a write during the
                  start-up, a read-only register), the data registers now and
                  what your sketch read last, and the last bus operations
                  decoded. Live - no Run button needed. In Proteus (U2 after
                  OSR 16 + FILTER 16): SCL 100.0 kHz measured, D0 = 60 read 1x,
                  1 soft reset, calibration 32 / 32, F2 = 05, ctrl_meas B7,
                  config 50.
  Timing          Good for: seeing how long one measurement takes at your
                  oversampling and if your sketch reads each one. Records the
                  next 5, 10 or 20 measurements: start, t_measure (the
                  measuring bit, against the data sheet's typical / maximum),
                  the period in normal mode (= t_measure + t_standby, the ODR),
                  the settings, and whether your sketch read each measurement
                  and how long after it ended - on a timeline and in a table.
                  With the demo: t_measure 8.000 ms (x1 / x1 / x1), period
                  133.000 ms (7.52 Hz); one reading a second reads 1 in 7 or 8.
                  In Proteus after OSR 16 (x10): t_measure 98.000 ms, period
                  223.0 ms (4.48 Hz), the sketch read 2 of 10.
  Step response   Good for: seeing how the IIR filter and your read rate delay
                  a sudden change before your sketch prints it. Steps the
                  temperature (+10 C), the humidity (+30 %) or the pressure
                  (-10 hPa), then times every measurement and every read of
                  your sketch as % of the step: the chip at 50 / 63 / 90 / 99 %
                  (ms and measurements) and when your sketch first saw 50 % and
                  90 %. The environment is given back afterwards. In Proteus
                  (U2, OSR 16 + FILTER 16, 4.48 Hz, temperature +10 C): 50 %
                  after 11 measurements (2340.8 ms), 90 % after 36 (7916 ms),
                  99 % after 72 (15943.8 ms); the sketch saw 90 % at 8813.1 ms.
                  At x1 (7.52 Hz) the same 11 / 36 / 72 measurements take 1.3 /
                  4.7 / 9.4 s; filter off: the first measurement has it all.
                  (The humidity has no IIR filter on the real chip either.)
  Altitude        Good for: seeing what altitude your sketch reports while the
                  sensor climbs, and how much the filter lags. The pressure
                  follows a 10, 100 or 500 m climb in 10 s, then holds 3 s; the
                  chart shows the true altitude and the altitude of each
                  pressure your sketch read (44330 (1 - (p / p0)^0.1903), the
                  Adafruit formula, p0 = the sea-level pressure on the Weather
                  page): reads, the maximum error, the average lag and when it
                  settled after the stop, and one pressure count in cm. In
                  Proteus (U2, OSR 16 + FILTER 16, a reading a second), +100 m:
                  13 reads, max error 32.55 m, lag 2351 ms, not settled within
                  the 3 s - the filter 16 lag. Without the filter it follows
                  closely: on a PC with the demo sketch, RATE 200, filter off:
                  65 reads, max error 1.31 m, lag 87 ms.
…