MoleGraph is an open-source, low-cost school probeware system designed for hands-on STEM education. Unlike commercial "black box" solutions, it follows a "white box" approach, allowing students and teachers to understand the inner workings of measurement technology, electronics, and sensor calibration.
By engaging in the DIY (Do-It-Yourself) assembly process—which includes soldering, 3D printing, and component sourcing—users develop deep technological literacy and critical thinking skills.
The system is built on the Arduino platform, specifically utilizing the Arduino NANO (ATmega328) microcontroller and an HC-05 Bluetooth module for wireless connectivity.
- MoleGraph Shield U01: A custom-designed expansion PCB that features standard RJ12 connectors for robust and reliable sensor connectivity, replacing unstable breadboard wires.
- Mechanical Compatibility: All components are housed in 3D-printed cases (MoleBoxes) that are fully compatible with the m-BITBEAM and BITBEAM open-source construction sets.
- LEGO Integration: These cases share dimensions and hole spacing with LEGO Technic, allowing sensors to be integrated directly into robotic and mechanical models.
| Feature | Specification |
|---|---|
| Sensor Ports | 4× RJ12 ports, each equipped with a programmable function button (e.g., for sensor resetting or triggering). |
| Actuators | Ports 2 and 3 natively support the connection of servo motors, enabling automation and robotics tasks. |
| Status Indicators | Onboard LEDs for battery status, active Bluetooth/USB connection, and ongoing data recording. |
| Power Supply | Flexible power via a 9V battery (6LR61) or a USB connection. |
| Connectivity | Dual communication modes supporting USB cable (serial-to-USB) and wireless Bluetooth SPP. |
| Analog Sensors | 0–5V range using the integrated 10-bit ADC. |
| Digital Sensors | Supports protocols like I²C, OneWire, and PWM. |
| Extensibility | Currently MoleGraphAuto library supports 30+ sensor types. Includes "universal cables" and breadboard modules for connecting any custom 0–5V sensor. |
The system includes a powerful cross-platform application and a specialized firmware layer.
| Feature | Details |
|---|---|
| Platforms | Native support for MS Windows, Linux, macOS, and Android. |
| Measurement | Manages up to 8 independent channels simultaneously. |
| Sampling | Continuous sampling (up to ~1 kHz for one analog) or on-demand sampling triggered manually. |
| Visualization | Real-time graphs (with multiple independent Y-axes) and digital panels for numerical display. |
| Analytics | Graph reading tools and basic statistics (min, max, mean, median, standard deviation). |
| Calibration | Built-in calibration/correction dialog using formula, e.g. |
| Education | Teachers can create experiment templates ("Save/Open without values"), allowing students to start measuring immediately. |
| Export | Export results to CSV (tabular data) and graphs to PNG images. |
MoleGraph facilitates a smooth transition from basic measurements (MoleGraphAuto library) to advanced coding and engineering.
Beginners can use Blockly@rduino with a custom MoleGraph extension (and MoleGraphManual library) to build programs graphically, automatically generating standard Arduino (C++) code.
The MoleGraphManual library allows for custom firmware development in the Arduino IDE, enabling simultaneous data transmission and control of external actuators.
Highly compatible with projects like the "Fretka" robot, which can transmit real-time sensor data wirelessly to the MoleGraph application.
QT version is 5.10.1 (QT Creator 4.5.1) downloaded from https://download.qt.io/new_archive/qt/5.10/5.10.1/.
Open Qt Creator project SerialToGraph/SerialToGraph.pro. Set release build Project->Build Settings->Realease and Build Project. Build install image file by run Qt util macdeployqt, see below. This step includes frameworks and libraries in the application.
~/Qt5.10.1/5.10.1/clang_64/bin/macdeployqt <path to MoleGraph.app> -verbose=2 -dmg
Double click on MoleGraph.dmg to mount image file and than install it by copying MoleGraph.app to your Application folder.