In this meeting we discussed how the PIC (Projeto Integrador de Curso) works, as well as the tasks we would need to carry out throughout the second semester.
The team met to discuss and determine which companies it would make most sense to visit in order to validate our project. After evaluating the options, we provisionally decided to proceed with visits to three locations: the Instituto Nacional de Saúde Dr. Ricardo Jorge, Transaire, and the Pingo Doce in Minde.
On January 28, 2026 the team visited the Instituto Nacional de Saúde Dr. Ricardo Jorge to understand the work environment, hear the workers' needs, and establish a partnership for future visits and prototype testing.
Speaking with the Food and Nutrition department — which receives weekly samples of seafood, cheeses, and cured meats — we realized the current monitoring device is extremely outdated and inflexible. The worker accompanying us had enormous difficulty operating it, which in turn made the communication between our team and the Institute easier, as the workers' needs became very clear.
First, the device requires a specific base station to transmit data to a local computer. Additionally, the software was very confusing and complex. We concluded that we needed a product that sends trip data directly to a computer remotely, and that the software needs a user-friendly interface. Second, monitoring not only temperature but also humidity was something requested of us.
In summary, the visit proved to be a crucial milestone. Beyond validating the failures of current monitoring systems and defining essential technical requirements — such as remote data transmission, an intuitive interface, and combined temperature and humidity measurement — the meeting ended with the closing of a partnership with the institution for future prototype testing.
We visited the Pingo Doce in Minde and were shown the cold storage units on-site. However, the visit was not as productive as hoped because an external company handles all of their logistics, so the staff could not explain the day-to-day problems they face or how measurements are carried out.
On February 18, 2026 we visited Transaire to see how the company operates in practice and understand their logistics. We were welcomed by the owner and a secretary, who showed us the warehouses and explained everything required for transporting food goods.
We were told that temperature control of food in a refrigerated unit is already a mandatory requirement in the sector. They explained that cold storage warehouses and trucks must circulate with thermal sensors to prove to clients that the cargo has always traveled safely.
When we mentioned our idea of including a humidity sensor, they were very enthusiastic because one of the problems they face when transporting fresh produce, such as lettuce, is that the dry air and the technology used to prevent ice buildup in the unit often ends up "burning" the products and spoiling them. This proved to us that combining both measurements can help solve a real problem they face.
In summary, the visit to Transaire was essential for the project's progress. We validated the technical needs of the device and confirmed that the humidity sensor has practical value. We also took the opportunity to strengthen the partnership, and it was discussed that the company could be used for testing our prototype.
On February 23 the team presented the project proposal to Professor Luís Caldas Oliveira, Afonso Cruz, and the fellow students who share the same PIC mentor.
The first of the fortnightly seminars held throughout the semester, featuring Miguel Gonçalves, CEO of Magma Studio — a consultancy focused on recruiting and managing young talent in the business and education sectors. He shared strategies on how to attract and engage beneficiaries and partners in the innovation development process, which is fundamental for the PIC. Our group's project was addressed and discussed by him personally.
In this meeting we presented the progress made so far and discussed potential ideas and implementation methods, as well as the technologies and components needed to build the device.
On March 11, 2026, the team participated in the second seminar of the program, "Requirements Engineering: From the User's Voice to the Technical Specifications of the Prototype". The session featured Rúben Oliveira, founder of Vision Volt, and Diogo Henriques from Genoa Spark — companies that develop products combining hardware and software.
During the seminar, the process of transforming user needs into technical requirements for prototype development was discussed. One of the key ideas highlighted was the importance of first defining the physical context of the product — such as the enclosure or form factor where the device will be installed — before starting to build the prototype.
It was also explained that the development process involves multiple iterations and changes over time, and it is normal for the prototype to undergo modifications as new needs and limitations are identified.
At the end of the session, several questions were clarified about how to choose the appropriate components for the project, taking into account the technical requirements and practical limitations of the device.
On March 13, the team visited Farmácia Duarte e Raimundo in Monte Real during product delivery hours and spoke with the distributor to understand how refrigerated pharmaceuticals are monitored, as well as to observe how these products are transported.
The products are transported in plastic boxes insulated with polystyrene and ice packs, with unique barcode stickers on each box. Temperature monitoring is only carried out in the trucks and warehouses, often leaving room for temperature spikes that exceed the required limits — particularly in summer — during the unmonitored transitions between truck and warehouse, and truck and pharmacy. Truck doors are often left open during deliveries, causing the interior temperature to rise. The current prevention measures against temperature increases during these movements are the polystyrene and ice packs which, especially in summer, are no longer cold enough by mid-afternoon to maintain a low and controlled temperature.
With this visit, we validated the need for a reliable system that measures temperature to ensure that no temperature threshold was exceeded throughout the entire transport chain, as well as the ability to place the device inside each box and monitor it individually, taking advantage of the individual identification already in place for each box via barcode.
On March 13, we went to Farmácia Moderna in Minde to understand how they store and transport sensitive products such as medicines and vaccines. They showed us the premises and explained the gaps and challenges that exist in the logistics until the boxes reach them.
They told us that inside the pharmacy the standards are very high: they are required to have multiple temperature and humidity sensors (one in each room). But during transport the reality is different. They explained that the trucks often only have a single temperature sensor and are not well insulated. The biggest problem they reported is not the journey itself, but the transitions: the moments when the boxes pass from warehouses to vans, and then from vans to the pharmacy. Couriers often leave the boxes outside the van or leave the van door open, causing them to lose temperature, especially in summer.
The medicines travel in plastic boxes (approximately 30×50×30 cm) lined with polystyrene and cold accumulators. Since the couriers leave the boxes but later take them back for reuse, we quickly saw the opportunity: we can perfectly place our temperature and humidity device inside. Even with the polystyrene and ice, there is more than enough space for our sensors to accompany the entire journey and monitor what happens during these transitions.
In summary, the visit to Farmácia Moderna showed us exactly where the cold chain fails the most: during loading and unloading. We also validated that the transport boxes have more than enough space to fit our future prototype. This will allow us to build the device with the certainty that it will fit inside.
On March 13, 2026, the team visited Pingo Doce Express IST to understand how food preservation works and how transported food is verified. One of the store managers explained that food transport is handled by an external company using a fully sealed refrigerated container, similar to Transaire. We concluded there was no problem we could solve for Pingo Doce, as the refrigeration of food — whether in transport or in supermarkets and restaurants — does not present any failures or issues.
In this meeting we discussed all the requirements for our project. The system we designed is meant to operate inside transport boxes. To ensure the device is maintenance-free, we decided to use a supercapacitor instead of conventional batteries. Charging will be done by induction before each transport. This approach demands good energy management, so the circuit integrates a Step-Down regulator for protection against inrush currents during charging and a Step-Up converter to stabilize the voltage supplied to the components. Our goal is to guarantee a minimum autonomy of 24 hours running exclusively on this source.
The hardware architecture is based on a microcontroller with an integrated BLE radio, such as the ESP32 or the Arduino Nano. The circuit also includes an RTC (Real-Time Clock) for timestamping and the respective temperature and humidity sensors. To maximize energy savings, the firmware will operate mostly in sleep mode. We defined a state machine that wakes the device at 100-second intervals solely to take readings.
At the end of the trip, the data history is automatically sent via Bluetooth Low Energy (BLE) to a local Gateway at the destination, which forwards everything to the Cloud, making it accessible on the client’s dashboard.
On March 21, our team met to organize ideas and define the components to order for the project. We chose the components according to our budget, the project's construction needs, and possible alternatives. One of the issues we found was the lack of a 25-farad capacitor rated at 5 V, requiring us to use two 50-farad capacitors rated at 5 V instead.
In this meeting, we presented the progress made to the professor, focusing on the components and specific models we plan to use. The professor commented on the work carried out in relation to the previously defined project requirements. Additionally, we discussed the best options for implementing our solution in a real-life scenario, as well as the technical specifications the final system will need to meet.
On March 25, 2026, the team participated in the third seminar of the program, on the topic "Computer Vision and IoT Sensors: The Technologies Behind the Sensei Experience". The session featured Nuno Moutinho (CTO) and Paulo Carreira (CSO) from Sensei, a company that develops technology for autonomous stores and competes directly in the global market with giants like Amazon.
One of the central points of the discussion was the critical importance of component calibration. It was highlighted that, despite being a laborious process, this precision is what guarantees the system's reliability in real-world environments. This insight reinforced our approach with ElectroCap, underscoring that rigorous hardware parameterization is essential for seamless logistics monitoring.
On March 31 we revamped our EletroCap presentation to document the project's evolution. We added topics such as the problem of thermal "blind spots" in the cold chain and certain trade-off decisions we have been facing — from the choice of supercapacitors to energy optimization through sleep-mode.
In this meeting we informed the professor where we would begin the prototype development and how we planned to do it.
Collection of materials to start building the prototype
Start of prototype construction
Start of the database development using Firebase as a base, as well as the start of the website development using Streamlit.
Using a multimeter, we measured the voltage of the induction coils to make sure everything was fine with the coils and that we wouldn't swap any cables during soldering, since their polarity wasn't labeled.
Assembly of the entire circuit. This includes soldering pins to components such as the ESP32. In this first assembly phase, we used cables and soldered the components in a "floating" manner, using a breadboard only for the Raspberry Pi and the ESP32. We didn't use a breadboard for all the other components.
After speaking with Professor Luís Caldas de Oliveira, we were advised not to use the approach of leaving the components "floating" as mentioned previously. As a solution, we started using pins on all components and a breadboard to connect everything. This solution made everything safer and more organized.
We concluded an initial version of the dashboard capable of recognizing simulated measurements in the database and presenting their graphs.
We completed the first version of the MCU Firmware capable of connecting via BLE (tested by connecting to a mobile phone using the nRF Connect for Mobile app) and sending measurement data along with the timestamp.
With the assembly completed, we started practical tests to validate the hardware and integrate it with the firmware.
During the testing phase, we faced an issue with the supercapacitors' energy retention, which forced us to optimize the system's power consumption. To solve this, our focus turned to implementing deep sleep mode on the microcontroller. In parallel, we configured the RTC's alarm pin to manage the activity cycles. This way, the system sleeps and the RTC wakes it up only when it's time to take measurements.
During testing, we encountered an experimental issue when we had been charging the supercapacitors for a while. We noticed that the transmitter module was getting too hot. Upon inspecting the components more closely, we found that one of the integrated circuits had created a bubble on its surface, a sign that it had burned out. Given the situation, we paused the tests and sent an email to the professor to report what had happened.
We completed and tested the gateway code capable of requesting and receiving data from the MCU and sending it to the database.
Nesta reunião apresentamos o que já tínhamos feito em relação ao projeto e o problema de um circuito integrado da bobina que sobreaqueceu durante o carregamento por indução. Veio a ser discutido com o professor que esta falha foi causada por um pico de corrente, pois ao contrário de bateria que tem uma resistência interna que limita a quantidade de energia que entra, os condensadores não têm, o que resulta num carregamento quase instantâneo por pico de corrente muito alta, que resultou no sobreaquecimento do circuito integrado.
We had the idea of creating code for a start gateway that initiates the MCU's journey and saves the minimum and maximum temperature values as well as the minimum and maximum allowed humidity and the journey start date in the database. We also changed the MCU code to act in accordance with this new gateway. We updated the end-of-journey gateway to permanently put the MCU to sleep until one of the MCU pins is activated.
We started researching how to make the poster, following the professor's instructions as well as examples from previous years.
We added a button that wakes the MCU from the deepsleep that the end gateway put it in, in order to start the entire journey process. We decided to implement this new manual component because we understand that if the device has to be manually placed inside the box, adding the need for a button click would not have a major influence on our goal of being a practically autonomous system.
We tested the accuracy level of our system using a thermometer. We tested in various locations and at different times of the day (Living room, refrigerator, outside in the sun, outside in the shade) and concluded that we have an accuracy of +/- 0.2 degrees.
No dia 20 de maio após a verificação com os primeiros valores reais, demos como finalizado o site.
On May 22nd we concluded the 3D modeling of the case that will cover our prototype. We paid due attention to the thickness of the case in the area that would hold the charging coil. The next step will be to turn this digital model into reality. We have already ordered the model to be manufactured using a 3D printer. With this model in hand, we will be able to go to our partners to begin real tests.
Nesta reunião foram esclarecidos e apresentados possíveis problema pelo Professor como o que acontece se houver enganos pela parte dos trabalhadores na gateway do inicio, sendo necessário reforçar o código em relação a esse problema, o problema com o gasto energético, teremos de testar melhor a autonomia e o gasto de utilização do protótipo. Foi nos aconselhado começar a falar com os nossos partners para combinar testar o nosso protótipo para obter feedback e pedir feedback em relação à interface do site. Ao fazer o vídeo incluir uma entrevista a pessoas que iram usar o nosso produto. Em relação ao poster este tem que apresentar como se fosse uma história para ser mais apelativo, apresentar como o protótipo iria funcionar, que neste caso seria dentro da caixa dos medicamentos e colocar diversas imagens para que o poster seja mais apelativo.
Continuámos a trabalhar no poster seguindo as alterações e recomendações dadas pelo professor na reunião.
Validamos quanto tempo dura a bateria dos nossos supercondensadores com o projeto a funcionar de forma normal. Fizemos 3 testes ao longo de 3 dias e chegamos à conclusão que embora os nossos cálculos apontassem para uma autonomia de cerca de 24 horas, apenas tivemos uma autonomia média de 10 horas.
Iniciámos a criação da nossa apresentação final do projeto.
Iniciámos a gravação e edição do vídeo de demonstração do nosso projeto.
No dia 8 de junho de 2026 realizamos testes ao protótipo ChainGuard com o apoio do nosso partner Instituto Nacional de Saúde Ricardo Jorge (INSA). O protótipo realizou uma viagem de Lisboa a Évora (Laboratório Regional de Saúde Pública de Évora). Este teste foi bem sucedido, tendo conseguido ver com sucesso os dados na dashboard.
Conclusão e entrega dos materiais para avaliação do PIC.