Project Files of 6V Mini Solar Panel Library for Proteus V1.0 (Arduino, INA219)

6V MINI SOLAR PANEL LIBRARY FOR PROTEUS - V1.0 (a 6 V mini solar panel, 12
cells, no bypass diode: its I-V curve with the light, the heat and the shade,
the hot spot of a shaded cell, and why 5 V indoors is not power)
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/2026/11/6v-mini-solar-panel-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 - its own article:
  https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
The demo measures the panel with our INA219 Current Sensor and its DC
electronic load - a SEPARATE library, not in this package: download and
install it first - its own article:
  https://www.theengineeringprojects.com/2026/10/ina219-current-sensor-library-for-proteus-v1-0.html
The big brother, our 12V Solar Panel (36 cells, bypass diodes):
  https://www.theengineeringprojects.com/2026/11/12v-solar-panel-library-for-proteus-v1-0.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
6V-Mini-Solar-Panel-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                              201.9 KB   TEP Arduino boards V4.0 (UNO) -> LIBRARY
|   |-- TEPMINISOLAR.LIB                               20.8 KB   the library -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                883.5 KB   the Arduino board model -> MODELS folder
|   |-- TEPMINISOLAR.DLL                              309.0 KB   the model -> MODELS folder
|-- Proteus Simulation/
|   |-- 6V-Mini-Solar-Panel-INA219-ArduinoUnoV4.pdsprj   25.0 KB   the demo project
|   |-- MiniSolar_Demo.hex                             24.9 KB   the demo firmware
|   |-- TEPARDUINO.DLL                                883.5 KB   copy of the board model
|   |-- TEPMINISOLAR.DLL                              309.0 KB   copy of the model
|-- Arduino Code/
|   |-- MiniSolar_Demo/MiniSolar_Demo.ino               4.8 KB   the demo sketch (source of the .hex)
|-- README.txt                                        ~19.7 KB   this file
Total: 2.62 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
A simulation model of the "6 V" mini solar panel - the small epoxy panel of
1 to 3 W that powers garden lights, Arduino and ESP32 projects, battery
chargers, toys and school experiments. Our own model:
  * 12 cells in series (6 x 2) and NO bypass diode. Each cell follows the
    single-diode model; the panel is fitted so it gives exactly its rated
    watts at the standard test conditions (STC: 1000 W/m2, cells at 25 C):
    Voc 7.2 V, about 5.8 V at the maximum power point (MPP), Isc 185 mA per
    rated watt (0.37 A for 2 W).
  * Its current depends on the voltage the circuit holds it at: the I-V
    curve. Ask for less current and the voltage rises towards Voc; ask for
    more than the light makes (Isc) and the voltage collapses. Only one
    point gives the most power - the MPP - and it moves with the light.
  * The light (property IRRADIANCE and the pop-up's chips Night, Indoors,
    Cloudy, Full sun): the current follows it; the voltage only falls a
    little in weak light - indoors (about 10 W/m2) the panel still shows
    about 5 V open, but gives only a few milliwatts.
  * The heat (property AMBIENT): in the sun the cells warm towards the air
    + 31 C (NOCT 45 C) over about 3 minutes; Voc falls 0.33 % a degree, Isc
    rises 0.05 % a degree, the power falls about 0.43 % a degree.
  * The shade (pop-up chips): with no bypass diode all 12 cells carry the
    same current, so a leaf on ONE cell starves the whole panel. When the
    load wants more than the shaded cell makes, the other 11 drive it into
    reverse - it turns the power into heat, a hot spot. A shadow over half
    of the cells (6 at 30 %) cuts the panel to about a third.
  * At night, with a battery straight on it, current flows back INTO the
    panel (about 2 mA from a full Li-ion cell); a source the wrong way round
    drives current through its cells the wrong way.
  * The cells' capacitance (about 0.9 uF on a 2 W panel) is in the circuit
    too, so a load that wants more than the panel makes collapses it
    smoothly.
  * The watch: AT THE MPP, OUTPUT (with the share of the best this light
    gives), OPEN CIRCUIT, COLLAPSED, SHADED CELL IN REVERSE, NIGHT, REVERSE
    CURRENT, REVERSED, HOT, the light and the shade; the energy, and how much
    of what the light offered the load took.
The symbol is just the panel: the dark epoxy board with 12 dark-blue cell
strips (6 x 2) and their silver busbars, the red and black wires from behind
its left edge (the pins). At Run the cells' glare follows the light, they go
dark at night, and a leaf or a shadow over half of them lies on them. On the
board's bottom margin: the value line (the rating when stopped; the watts,
volts, amps and the state at Run), the OUT LED (green while it delivers
power) and the OPEN PANEL button. The value line, the LED, the button and the
shade on the cells are TEP additions; a real panel has none of them. The sun,
the clouds, the room lamp and the night are drawn in the pop-up.

ONE DEVICE (search "solar" in Pick Devices):
  MINISOLARTEP     "6V Mini Solar Panel V1.0"   (category Electromechanical >
                   Renewable Energy), model TEPMINISOLAR.DLL
  The pop-up panel "TEP 6V Mini Solar Panel" opens at Run (and with OPEN
  PANEL on the board) - the look of the TEP Serial Monitor. Tabs Panel,
  Graphs, Event log and Check; gear and ? icons for Settings and Help; the
  palette icon switches the theme:
    Panel      the light chips (Night, Indoors, Cloudy, Full sun) and the
               shade chips (No shade, Leaf, Half shade); the state in big
               letters; the I-V and P-V curves for this light with the MPP
               (green) and the panel's operating point (orange); the live
               values (the power, the state, the volts, the current, the best
               (MPP), the share the load takes, the light, the cells); the sky
               and the panel (the sun, clouds, a room lamp or the moon, the
               leaf or the shadow); the last 10 s: the power against the most
               this light gives.
    Graphs     the power against the best, the volts and the current over the
               last 10, 30 or 60 s. Live / Freeze.
    Event log  AT THE MPP, OUTPUT, COLLAPSED, SHADED CELL IN REVERSE, the
               light, the shade, the warnings; filters All / Output /
               Warnings, Pause, Clear
    Check      Good for: a panel that gives less than its label, a voltage
               that collapses, a project that stops in the shade - the light,
               the operating point, the load, the shade, the hot spot, the
               cells, the polarity, the energy, with tips
    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
A3 sheet, an Arduino UNO V4.0 with its built-in monitor, our INA219 - its
pop-up version - and its DC load at 340 mA, from their own library, the 2 W
panel in full sun; all pop-ups open). What the run showed:
  * Full sun, 340 mA: "AT THE MPP - 5.87 V x 0.340 A = 1.997 W (1000 W/m2,
    cells 25 C): the most this light gives"; the ON LEDs lit (UNO, INA219,
    the panel's OUT); the INA219's pop-up "MEASURING - BUS 5.840 V, SHUNT
    34.02 mV, CURRENT 340.2 mA, POWER 1.986 W".
  * The load's UNO preset (50 mA): "OUTPUT 7.08 V x 0.050 A = 0.354 W - 18 %
    of the 1.995 W it could give at 5.80 V"; the monitor: "enough for an
    Arduino".
  * MOTOR (0.8 A): "COLLAPSED - the load wants more than the 0.370 A this
    light makes: 0.27 V x 0.370 A = 0.099 W".
  * SERVO (0.25 A) and the Leaf chip: "A LEAF on one cell (set on the panel),
    no bypass diode: all 12 cells starve - the best now 0.488 W at 6.77 V",
    "SHADED CELL IN REVERSE - driven to -6.1 V by the others (a hot spot):
    0.22 V x 0.105 A = 0.023 W"; with 50 mA: "OUTPUT 6.96 V x 0.050 A = 0.348
    W - 71 % of the 0.487 W it could give at 6.76 V".
  * Half shade: "A SHADOW over 6 of the 12 cells (set on the panel), each at
    30 % - the best now 0.642 W at 6.08 V"; at 50 mA "OUTPUT 6.72 V x 0.050 A
    = 0.336 W - 52 % of the 0.642 W it could give at 6.08 V".
  * No shade, Cloudy: "LIGHT 200 W/m2 - cloudy (set on the panel): the most it
    can give now is 0.364 W at 5.41 V"; at 50 mA "OUTPUT 6.01 V x 0.050 A =
    0.301 W - 83 % of the 0.364 W it could give at 5.41 V".
  * Indoors: "LIGHT 10 W/m2 - indoors (set on the panel): the most it can
    give now is 0.008 W at 3.78 V"; at 50 mA "COLLAPSED - the load wants more
    than the 0.004 A this light makes: 0.04 V x 0.004 A = 0.000 W"; the load
    switched off: "OPEN CIRCUIT - 5.08 V and no current: nothing takes the
    power (the most it could give: 0.008 W)".
  * Night: "NIGHT - no light: 0.00 V, the panel makes nothing".
  * Full sun, 0.25 A at the end: "OUTPUT 6.43 V x 0.250 A = 1.609 W - 81 % of
    the 1.975 W it could give at 5.74 V" (the cells at 29 C); the monitor's
    "best": "Best so far: 2.00 W at 5.87 V, 0.340 A".
  Plus automatic checks on a PC, 0 failed: 12 on the panel (1 / 2 / 3 W at
  STC: Voc 7.20 V, Isc 185 mA a watt, the rated watts at 5.81 V; 200 W/m2:
  0.369 W; 10 W/m2: Voc 5.17 V, Isc 3.70 mA, 7.8 mW; cells at 56 C: 13.0 %
  less; 1.88 mA back in from a full Li-ion cell at night; a leaf: 0.490 W,
  the shaded cell at -4.40 V at 2 V; half shaded: 0.649 W; the stamp with
  the DC load at 0.05, 0.33 and 0.8 A) and 4 on the pop-up (every page
  painted).

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" (TEPMINISOLAR.LIB and our
   Arduino library V4.0, ArduinoV4TEP.LIB) 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 TEPMINISOLAR.DLL and TEPARDUINO.DLL from "Proteus Model Files" to the
   MODELS folder (...\Proteus 8 Professional\MODELS). The demo's INA219 and
   DC load are NOT in this package: install our INA219 Current Sensor
   library the same way (its own ZIP - see IMPORTANT LINKS): TEPINA219.LIB
   and TEPINA219.DLL.
4. Delete TEPMINISOLAR.IDX from the LIBRARY folder if it is there.
5. Start Proteus. In Pick Devices (P) search "solar".

RUN THE DEMO
"Proteus Simulation\6V-Mini-Solar-Panel-INA219-ArduinoUnoV4.pdsprj" - keep the
.hex file and the DLLs beside the project (with the INA219 library
installed).
  ARD1: Arduino UNO V4.0 running MiniSolar_Demo.hex, its serial monitor built
        in (window "TEP Arduino UNO - ARD1").
  U1:   our INA219 (Advance: its pop-up), SDA / SCL on the UNO's A4 / A5 by
        labels; VIN+ on the PV+ net, VIN- straight into the load.
  LD1:  the INA219 library's TEP DC electronic load, 340 mA (the MPP of a
        2 W panel in full sun); - to ground.
  PV1:  the panel (WATTS=2, IRRADIANCE=1000, AMBIENT=25): + on the PV+ net,
        - to ground.
  1. Press Run. The monitor and the two pop-ups open (move them aside). In
     full sun at 340 mA the panel sits at its maximum power point.
  2. On the INA219's pop-up: the load presets (LED 20 mA, UNO 50 mA, SERVO
     250 mA, MOTOR 800 mA ...) and "Switch the load off" - watch the
     operating point move on the panel's curves.
  3. On the panel's pop-up: Night, Indoors, Cloudy, Full sun; No shade,
     Leaf, Half shade.
  4. Type in the monitor and press Send: best, reset, rate 500, help.
  5. Double-click PV1: WATTS (1 / 2 / 3), IRRADIANCE (W/m2), AMBIENT (C).

WIRING (the same idea in a project)
  A mini panel charges a battery through a charger made for solar input
  (a TP4056-type Li-ion charger, a CN3065 / CN3791 solar charger, or a
  small PWM controller for lead-acid), never straight: a battery on a bare
  panel runs back into it at night, and the panel's 7.2 V open-circuit
  voltage overcharges a Li-ion cell in the sun. To measure the panel with an
  Arduino, put a current sensor (INA219, INA226) in its + line and read the
  volts with a divider (7.2 V is too much for a 5 V analog pin: 1:2 is a
  safe ratio).
In the sketch (Wire only): read the INA219's shunt register (10 uV a step)
and bus register (4 mV a step, bits 15..3):
  float amps  = readReg(0x01) * 0.00001 / 0.1;      // the shunt volts / 0.1 ohm
  float volts = ((uint16_t)readReg(0x02) >> 3) * 0.004 + amps * 0.1;
The demo reads the bus before and after the shunt and only trusts a reading
when the two agree (the panel did not change in between), writes the
calibration (4096 for the 0.1 ohm shunt) so the INA219's own Current and
Power registers work too, and says when the panel gives enough for an
Arduino (0.25 W: about 50 mA at 5 V).
REAL HARDWARE:
 * The label's watts are for 1000 W/m2 and cells at 25 C: expect 70 - 85 %
   of it on a sunny day (warm cells, the angle, dust) - and almost nothing
   behind a window or indoors.
 * Point it at the sun and keep it out of shade: with no bypass diode a
   leaf on one cell costs about three quarters of the power.
 * Fit a blocking diode (a Schottky, 1N5817) if the charger has none.
 * A panel that shows 5 V on a meter can still give almost nothing: measure
   the current under load, not the open-circuit volts.

THE DEMO SKETCH ON THE SERIAL MONITOR (MiniSolar_Demo V1.0, 9600 baud)
  best      the best point so far          reset     forget it
  rate N    report every N ms (200 - 5000) help      the list
EXPECTED MONITOR OUTPUT
  6V Mini Solar Panel demo - The Engineering Projects
  The panel feeds the DC load through the INA219 (0x40 on A4 / A5, 0.1 ohm shunt). Set the load on its pop-up.
  Commands: best | reset | rate 1000 | help
  (then a line every second: PV, volts, amps, watts, and a note: enough for
  an Arduino, collapsed, open circuit or no light)

PROPERTIES (double-click the part > Edit Properties)
  WATTS       the panel: 1, 2 or 3 (W at STC); default 2
  IRRADIANCE  the light at the start, W/m2 (0 - 1200); default 1000
  AMBIENT     the air, C (-20 - 50); default 25 - the cells start at it
Every run starts again from the properties.

TROUBLESHOOTING
* COLLAPSED: the load wants more current than the light makes - a smaller
  load, more light, or a bigger panel.
* OPEN CIRCUIT: nothing takes the power - check the load's wiring.
* SHADED CELL IN REVERSE: a shaded cell is driven into reverse by the others
  (a hot spot) - remove the shade.
* REVERSE CURRENT: something pushes current into the panel (a battery at
  night) - fit a blocking diode or use a solar charger.
* REVERSED: a source is connected the wrong way round - check + and -.
* The part is not simulated: TEPMINISOLAR.DLL is missing from MODELS and from
  the project folder. No INA219 or no DC load: install our INA219 library
  (TEPINA219.LIB / .DLL). No UNO / no monitor window: TEPARDUINO.DLL, or click
  the UNO's USB port.
* The pop-up does not appear: click OPEN PANEL on the board, 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

LICENCES AND THIRD-PARTY NOTES
* The panel model (TEPMINISOLAR.DLL), the symbol and artwork and the Arduino
  Library V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL) are made by The Engineering
  Projects. The model is an independent implementation of the standard
  single-diode solar cell model, fitted to the typical data of 6 V (12-cell)
  mini panels. The models use only standard Windows libraries; no Visual C++
  redistributable is needed. The C++ source code is not included. The demo's
  INA219 and DC load, our INA219 Current Sensor library (TEPINA219.LIB /
  TEPINA219.DLL), are a separate download.
* The demo's .hex is built from the demo sketch and the Arduino AVR core 1.8.6
  (with its Wire library), 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 any panel
  maker, 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\MiniSolar_Demo\MiniSolar_Demo.ino, select
Arduino Uno and use Sketch > Export Compiled Binary. The sketch needs 9,060
bytes of flash (28 % of the UNO) and 496 bytes of RAM.

MODEL SCOPE AND LIMITS
Modelled: the cells (the single-diode model: the photocurrent, the diode, the
series and the shunt resistance), the shaded cells as their own group and
their reverse voltage, the light, the cells' temperature and its
coefficients, the warm-up, the cells' capacitance, the current flowing back
in, a reversed connection, the energy and the watch's states and warnings.
How it runs: at each Newton step the panel is in the circuit as the tangent
of its I-V curve at that step's voltage, plus its capacitance in transient;
the analog step is held to 0.1 ms after a change and grows to 1 ms when the
panel is steady, with smaller steps while its voltage swings.
Not modelled: the angle of the sun (set the light instead), spectral effects,
the shaded cell's temperature (the hot spot is reported, not heated), the
breakdown of a cell far in reverse, cell cracks, the slow loss of power over
the years, partial shading of a single cell's area (a shaded cell is a whole
cell at a share of the light).

VERSION
TEP 6V Mini Solar Panel library V1.0 (Oct 2026). Device MINISOLARTEP
(TEPMINISOLAR.LIB / TEPMINISOLAR.DLL). Demo sketch MiniSolar_Demo V1.0. Demo
sensor and load: INA219ADVTEP and DCLOADTEP (TEP INA219 Current Sensor library
V1.0, a separate library). Demo board: ARDUINO UNO V4.0 (TEP Arduino Library
V4.0) with its built-in serial monitor.