WEEKLY PLAN

Project Development: Complete your final project tracking your progress

PROJECT DEVELOPMENT

1. What will it do?

My project is a dual-axis solar tracker that automatically orients a small solar panel towards the sun throughout the day. It rotates in azimuth and tilts in elevation to maximise energy capture.

• It can be controlled manually via BLE with a mobile app interface to position it manually.
• It can start automatic tracking mode from the app.
• It has a “night mode” so when it gets dark it goes to a home position.

2. Who has done what beforehand?

Dual-axis solar trackers are used in solar farms and in many DIY maker projects. Commercial trackers are usually large, expensive systems designed for fixed installations. Online there are many hobby-level trackers using LDR sensors, Arduino or similar boards, and servo motors.

My project builds on these ideas, but focuses on:

• Using digital fabrication tools available in the Fab Lab.
• Integrating a custom electronics board and sensor array.
• Designing a compact, portable and aesthetically integrated system.

3. What will you design?

I will design:

The mechanical structure:

• Solar panel subframe.
• Tilt hinges and lugs to connect the linear actuator.
• Base with ball-bearing turntable and detachable legs.
• Supports, motor mounts and gear system for the azimuth axis.

The enclosure:

• Enclosure with panels for electronics, battery and wiring.
• Internal mounting plates for boards, drivers, and connectors.

The electronics:

• A custom microcontroller board, light sensor inputs and BLE interface.
• Integration of electronics and power management (battery / panel input / solar controller).

The app:

• App to control the panel via BLE.

4. What materials and components will be used?

Mechanical:

• Aluminium T-slot profiles for the panel frame.
• 3D-printed PETG parts (gears, sensor housing, hinges, enclosure cover plates, motor and electronics mountings).
• 10 mm plywood for enclosure base and legs.
• Ball-bearing turntable.

Actuation & motion:

• Linear actuator for elevation.
• Stepper motor + driver for azimuth.
• Couplings and shaft.

Electronics:

• Custom microcontroller PCB.
• Custom sensor PCB with array of phototransistors.
• Motor driver and relays.
• LiFePO4 12 V 6 Ah battery.
• DC-DC converter.
• Connectors, wiring, switches.

Solar:

• Two small solar panels with MC4 connectors.

5. Where will they come from?

• Most standard components (motors, linear actuator, bearings, screws, battery, solar panels) will come from common online suppliers and local hardware shops.
• Plywood will be purchased from a local store.
• Copper boards, connectors and electronic components will be provided by the local Fab Lab.
• 3D-printed and CNC-machined parts will be produced in the Fab Lab.

6. How much will they cost?

• The approximately cost of the project is 288.62 €
• To see a detail cost breakdown go to Bill of Materials in Project Develpment.

7. What parts and systems will be made?

I will fabricate the following:

• Solar panel subframe and hinges.
• Tilt lugs and mechanical linkage to the linear actuator.
• Base, legs and turntable integration.
• Gear system for azimuth.
• Custom electronics board for control and sensing.
• Sensor array housing with baffles for the light sensors.
• Internal and external enclosure parts and brackets.
• Integration and wiring.
• The programming and the app with BLE connection.

I will use off-the-shelf:

• Stepper motor, linear actuator, bearings and the ball-bearing turntable.
• Solar panels.
• Battery and some electronics modules (stepper motor driver, solar power controller, DC buck converter).

8. What processes will be used?

• Computer-aided design (CAD) for mechanical parts and assemblies.
• EDA (Electronic Design Automation) software for electronics and PCB layouts.
• 3D printing for gears, sensor mounts, custom brackets and enclosure parts.
• CNC cutting for the base and legs.
• Vinyl cutting for logo sticker.
• Vacuum forming for the sensor cover.
• PCB milling.
• Electronics soldering.
• Embedded programming of the microcontroller.
• Networking & communication (BLE).
• System integration & testing: wiring, debugging, calibrating motion and sensors.

9. What questions need to be answered?

Early-stage and design questions include:

• What is the optimal range and speed of motion for both axes?
• Is the linear actuator stroke and mounting geometry sufficient to reach the desired tilt angles?
• How accurate does the tracking need to be for a meaningful gain in energy compared to a fixed panel?
• What is the best control strategy?
• How will the system behave in wind and bad weather (home position, mechanical limits)?
• What are the power budget and autonomy (battery size vs consumption)?

10. How will it be evaluated?

The project will be evaluated by checking:

Functionality

• The tracker can rotate in azimuth and tilt in elevation as designed.
• It automatically tracks a light source and moves toward maximum intensity.
• It can retract to a safe “home” position.

Integration

• Mechanical, electronic, and software components all work together reliably.
• Wiring is safe, robust, and clearly organized.

Performance

• Repeatability and accuracy of tracking.

11. What tasks have been completed?

• Concept definition and basic requirements.
• Detailed CAD design of the structure, subframe, base and legs.
• Design and fabrication of hinges and actuator mounting geometry.
• Design and fabrication of gear system for azimuth.
• Integration and wiring of electronics systems.
• Fabrication and assembly of enclosure and mounting for all internal parts.
• Fabrication and assembly of base, legs and turntable.
• Fabrication of custom PCBs: embedded board, sensor array and power distribution board.
• Fabrication and integration of light sensor array.
• Initial programming for manual control and basic tracking logic.
• Design of app for solar tracker control via BLE.

12. What tasks remain?

• Some cable management.
• Calibration of sensor array and tracking parameters (thresholds, time intervals).
• Outdoor testing: tracking throughout a full day.
• Final documentation: BOM, schematics, CAD files, build steps, and evaluation.

13. What has worked? What hasn't?

What has worked:

• The mechanical structure is stable and the panel can move smoothly in both axes.
• The linear actuator and azimuth drive can be controlled reliably from the microcontroller.
• The BLE app works for manual control.
• The sensor array can detect direction of light and influence movement.

What hasn’t (or needed changes):

• Initial tilt geometry allowed angles that the actuator could not retract from, so I had to limit the tilt range and redesign some parts, including modifying the internal limit switches of the linear actuator.
• First tracking tests showed that the linear actuator was too fast, resulting in a shaky movement of the solar panel. This was resolved by fitting a PWM DC motor speed controller so I could adjust the speed of the linear actuator.
• Due to time constraints, limit switches for the rotation of the panels will be installed later on.

14. What questions need to be resolved?

• Final safe operating limits for the azimuth axis for real outdoor use.
• Long-term durability and weather resistance of printed parts and enclosure.
• Best control mode for different conditions (tracking, manual, park, night mode).
• Whether the additional complexity of dual-axis tracking gives enough extra energy compared to a simpler single-axis or fixed system in this scale.

15. What will happen when?

• Week 1: Final mechanical tweaks and full mechanical assembly.
• Week 2: Final wiring management. Programming refinement, calibration of movement and sensor thresholds.
• Week 3: Outdoor testing to check for performance and reliability. Final fixes. Complete documentation (website pages, images, diagrams, BOM, files), prepare slide and video.

16. What have you learned?

• How to go from an initial idea (that I thought was quite simple) to a fully integrated system combining mechanics, electronics, and software.
• Practical constraints of mechanism design: geometry and clearances.
• How to design, fabricate and debug custom PCBs and programming.
• The importance of iteration: some electronics, mechanical parts and coding needed redesigning.
• How to use multiple digital fabrication processes together to build one coherent product.
• How to plan, document, and communicate a project so that others can understand and reproduce it.