Photon is an educational robot by Photon Entertainment, a Polish company that aims to teach the basics of programming to pupils between the age of 5 and 12. Students can interact with Photon through a storytelling application that uses inputs from its young companions to move the plot forward. Educators also have access to a simplified programming paradigm to teach children how to control machines in fun and pedagogical ways. Individual users can purchase a Photon through the company store, and the system is easy enough even for parents and children who have no prior knowledge of programming. However, the robot is primarily seen in school as it helps entire classrooms become more familiar with technology while developing the students’ creativity and their interest in computer science.
This project is also highly symbolic because this educational robot full of ST components began with engineers who became familiar with our products while they were students themselves, thus reinforcing once again the importance of the strong presence of ST technologies in universities. Photon started with a dozen ST development boards, and the teams were able to create their various prototypes rapidly. We thus sat down with Michal Grzes, founder and CTO of Photon Entertainment, who told us that this ability to quickly iterate taught him a valuable lesson: put prototypes in the hands of a test audience as soon and as frequently as possible. Feedback is vital and understanding what features people appreciate and what functionalities they don’t care for will change how your teams approach the challenges they face. This is why Michal and his engineers quickly stuck with our solutions.
Photon’s Brain and Heart
Photon relies on an STM32F105 microcontroller (MCU) as the primary host. It is responsible for the most demanding computations and for talking to the users’ smartphones or tablets. It also offers various energy saving modes to push the battery to last longer. For instance, the power consumption in standby is only 1.9 µA, with the speed oscillator and real-time clock (RTC) off. There’s also a second microcontroller in the robot’s head, an STM32F0, that’s in charge of pre-processing some of the data from the sensors, as well as managing the RF module that the engineers put away from the main board to improve the signal and reduce the output power necessary. They thus decided to use a second MCU to reduce the number of cables, benefit from significant RF optimizations, and simplify the overall designs.
Their choice of STM32 MCUs is also fascinating because of how they got to the final design. As Michal explained:
“We used the CubeMX approach to go from the Discovery Boards to our PCB, but also to experiment with various microcontrollers. It made swapping components easy so that we could try different pins, various packaging, and more or less memory. We ended up trying six or seven different MCUs from the same family to see which one would work best and using CubeMX helped us speed up developments.
Photon Entertainment also relied on X-CUBE libraries to jump-start their application, and they told us that some of our open-source code even made it to their final product, which is the best testament to the importance of having an entire ecosystem, rather than merely manufacturing silicon.
The engineering team decided to put the world’s smallest time-of-flight (ToF) sensor, our VL53L0X, on the front of the robot for obstacle avoidance purposes. Its 940 nm VCSEL laser offers an absolute range of up to two meters and measurements take about 30 ms. However, our time-of-flight sensor wasn’t the only model they tried. As Michal recounted:
“Very early in the development, we experimented with many sensors from various companies, to figure out the most important features for our design and test the possibilities of each component. That’s when we learned that two meters were a good range for our application and that it needed to work on a broad range of textures, surfaces, colors, as well as a wide range of angles to offer a great user experience.”
In the end, he found that only one component would work best behind their 0.5 mm thick glass: our VL53L0X. Michal’s team also used the X-NUCLEO-53L0A1 Discover Board, which integrates the ToF sensor, and experimented with the cover glass we provide with the platform. The X-CUBE-53L0A1 software expansion pack also helped the engineers take advantage of the sensor’s features faster. They explained that the performance of the ToF was vastly superior to the competition and that by choosing our component, they could spend more time on the cover glass that would house the MEMS, to guarantee optimal performance.
Photon’s Sixth Sense
Our STC3100 gas gauge monitors the robot’s battery, by offering a Coulomb counter, while also checking the critical parameters of the single cell Li-Ion battery, such as the voltage, temperature, and current, to ensure the user’s safety. Photon Entertainment decided to rely on that device because of its precision, performance, and ease of use. By implementing our algorithms, the designers could confidently offer crucial features without spending an inordinate amount of time developing such solutions. As the company learned the importance of prototyping faster to get as much feedback as they could, it was essential to use our turnkey solutions so engineers could instead focus on optimizing the user’s experience. Choosing more of our components also helped them get better discounts and get more support from our experts.
This is also why Photon uses our LIS2DH three-axis accelerometer. Michal admitted that his design didn’t need a high precision inertial sensor since the Micro-Electro-Mechanical System (MEMS) focuses on strong shakes and grand rotations detection. However, by using more ST pieces, they were able to secure a much better price than what the competition could offer, and they got to centralize customer support, highlighting the importance of our ecosystem for startups that are hugely sensitive to these types of considerations. They were also able to use our libraries and build upon them to reduce the component’s power consumption. Since their application can tolerate a lesser precision, they use the LIS2DH’s power-saving measures to ensure the battery can last longer.
More Than the Sum of Its Parts
Photon recently won the Toy of the Year 2018 distinction as well as the best Polish market implementation, and we are proud that so many of our components are driving this innovation that is planting the STEM seed in the makers of tomorrow. It is no surprise that Photon Entertainment also received the award for the best startup in Europe by the European Business Angels Network (EBAN). They offer a solid foundation for children taking their first step in the programming world thanks to an innovative platform and intuitive applications. And we are proud to be a part of this extraordinary adventure that shows that by using the best and most efficient hardware, teams can focus on all the other things that will make their products remarkable. Photon is available for about €200 in the company’s store.