Greetings,
German Open 2025
We are Team S.A.R.C.A.T, a group of three enthusiastic students competing in the RoboCup Junior Soccer league. This season, we qualified through the regional tournaments for the German Open, where we achieved 4th place in the 2vs2 Lightweight League.
In the 2vs2 LWL, four autonomous robots compete against each other in a miniature soccer field. Each team builds and programs its own robots, which must sense, navigate, and play completely independently. To detect the ball, which emits infrared (IR) light, we use IR photodiodes/phototransistors that allow our robots to track its position in real time.
Our team focuses on combining mechanical design, electronics, and programming to create reliable and competitive robots. Each member contributes unique skills: from coding the AI that makes real-time detections, to designing robust hardware, to fine-tuning sensors for accuracy.
Design
Our robots are built using a modular approach: each subsystem is designed as a separate module that communicates via the I²C bus. This architecture offers two major advantages:
- It limits the risk of cascading failures — for example, an error in the motor PCB won’t damage other components.
- It makes modules easy to swap out or upgrade during development.
PCBs
Our robot uses two main PCBs and two sensor PCBs:
- Bottom Main PCB
- Hosts the motor controllers
- Provides voltage regulation (5V and 3.3V)
- Contains an ESP32 microcontroller
- Connects to the I²C bus, receiving drive vectors or controlling peripherals such as the solenoid kicker and dribbler
Top Main PCB
- Hosts the Compute Module 4
- Breaks out connections to Ethernet and USB
- Serves as the bus master, controlling the robot with access to both vision and sensor data
Future
This year, we are advancing to the RoboCup Junior Soccer Open League, where ball detection is performed via computer vision instead of IR sensors. This step pushes us to further develop our hardware and AI capabilities.
Sponsoring
A huge thanks to Aisler for supporting us through their Student Team Sponsorship program. Their support will be invaluable in manufacturing our PCBs this season. By working with Aisler instead of overseas manufacturers, we can significantly reduce lead times by avoiding long shipping and customs delays — allowing us to iterate faster on prototypes.