Fenrir Project - Universal Robotic Platform

The Fenrir Project is an open source of a multi purpose education robot dedicated for wide range of applications and usage in high-schools and universities.

The robot is based on Raspberry Pi 4 and Arduino Nano. The Raspberry Pi provides computational power, ROS2 support, WiFi connection and USB support. The Arduino Nano extends the PRi IOs and handles peripherals.

The development is currently still under development

Robot Overview

Robot visualization

Overview schematic

Power supply schematic

Wiring Overview

Note: The sensors numbering goes from left to right

• Ultrasound 1 - left, Ultrasound 2 - center, Ultrasound 3 - right
• Line sensor 1 - left, Line sensor 2 - right
• Motor 1 - left, Motor 2 - right
• Encoder 1 - left, Encoder 2 - right

Module A	Pin	Module B	Pin	Type	Length	Note
Battery 1	-	PD Module	-	USB-C - USB-C	15cm	-
Battery 2	-	Raspberry Pi	-	USB-C - USB-C	15cm	-
Raspberry Pi	-	Camera	-	CSI Cable	10cm	-
Raspberry Pi	3v3	GPS	VCC	wire (blue)	10cm	3V3
Raspberry Pi	GND	GPS	GND	wire (black)	10cm	GND
Raspberry Pi	Rx	GPS	TxD	wire (purple)	10cm	UART
Raspberry Pi	5V	I2C Board	5V	wire (red)	8cm	5V
Raspberry Pi	GND	I2C Board	GND	wire (black)	8cm	GND
Raspberry Pi	SCL	I2C Board	SCL	wire (yellow)	8cm	SCL
Raspberry Pi	SDA	I2C Board	SDA	wire (green)	8cm	SDA
Raspberry Pi	-	LIDAR	-	USB-A - microUSB	10cm	-
I2C Board	5V	LCD	VCC	wire (red)	8cm	5V
I2C Board	GND	LCD	GND	wire (black)	8cm	GND
I2C Board	SCL	LCD	SCL	wire (yellow)	8cm	SCL
I2C Board	SDA	LCD	SDA	wire (green)	8cm	SDA
I2C Board	5V	Arduino	VCC	wire (red)	15cm	5V
I2C Board	GND	Arduino	GND	wire (black)	15cm	GND
I2C Board	SCL	Arduino	SCL	wire (yellow)	15cm	SCL
I2C Board	SDA	Arduino	SDA	wire (green)	15cm	SDA
Arduino	US1	Ultrasound 1	Vcc	wire (red)	10cm	5V
Arduino	US1	Ultrasound 1	GND	wire (black)	10cm	GND
Arduino	US1	Ultrasound 1	Echo/Trig	wire (blue)	10cm	signal
Arduino	US2	Ultrasound 2	Vcc	wire (red)	10cm	5V
Arduino	US2	Ultrasound 2	GND	wire (black)	10cm	GND
Arduino	US2	Ultrasound 2	Echo/Trig	wire (blue)	10cm	signal
Arduino	US3	Ultrasound 3	Vcc	wire (red)	15cm	5V
Arduino	US3	Ultrasound 3	GND	wire (black)	15cm	GND
Arduino	US3	Ultrasound 3	Echo/Trig	wire (blue)	15cm	signal
Arduino	Line1	Line Sens. 1	VCC	wire (red)	15cm	5V
Arduino	Line1	Line Sens. 1	GND	wire (black)	15cm	GND
Arduino	Line1	Line Sens. 1	A0	wire (blue)	15cm	signal
Arduino	Line2	Line Sens. 2	VCC	wire (red)	15cm	5V
Arduino	Line2	Line Sens. 2	GND	wire (black)	15cm	GND
Arduino	Line2	Line Sens. 2	A0	wire (blue)	15cm	signal
Arduino	5V	Encoder 1	-	wire (yellow)	20cm	5V
Arduino	GND	Encoder 1	-	wire (brown)	20cm	GND
Arduino	EN1A	Encoder 1	-	wire (red)	20cm	A
Arduino	EN1B	Encoder 1	-	wire (orange)	20cm	B
Arduino	5V	Encoder 2	-	wire (yellow)	20cm	5V
Arduino	GND	Encoder 2	-	wire (brown)	20cm	GND
Arduino	EN2A	Encoder 2	-	wire (red)	20cm	A
Arduino	EN2B	Encoder 2	-	wire (orange)	20cm	B
Arduino	GND	PD Module	OUT-	wire (black)	-	-
Arduino	M1A	H-Bridge	IN3	wire (yellow)	20cm	PWM A+
Arduino	M1B	H-Bridge	IN4	wire (green)	20cm	PWM A-
Arduino	M2A	H-Bridge	IN1	wire (yellow)	20cm	PWM B+
Arduino	M2B	H-Bridge	IN2	wire (green)	20cm	PWM B-
PD Module	+	H-Bridge	+12V	wire (orange)	15cm	12V
PD Module	-	H-Bridge	GND	wire (black)	15cm	GND
H-Bridge	OUT1+	Motor 1	-	wire (green)	20cm	+
H-Bridge	OUT1-	Motor 1	-	wire (blue)	20cm	-
H-Bridge	OUT2+	Motor 2	-	wire (green)	20cm	+
H-Bridge	OUT2-	Motor 2	-	wire (blue)	20cm	-

Equipment

Role	Component	URL
Main Computer	RPi	link
Helper Microcontroller	Arduino Nano	link
2x Battery	Powerbank 10000 mAh	link
Camera	RPi Camera v2	link
GPS	NEO-7M module	link
2D LiDAR	RPLiDAR A1M8	link
LCD	HD44780 20x4 I2C	link
3x Ultrasound	SRF-05	link
2x Line Sensor	TCRT5000 module	link
H Bridge	L298N module	link
Motor with Encoder	DG01D‐E	link
IMU	MPU6050	link
Barometer	BME280	link
Real Time Clock	DS3231	link
ADC	ADS1115	link
UWB (not yet)	DWM1000	link
DC/DC Step Up	XL6009	link
Power Delivery	USB-C PD module	link
Switch		link

Acknowledgments

This work was created with the support of project RP182401001 under the PPSŘ 2025 program.

Authors

Adam Ligocki - [email protected]

Petr Šopák - [email protected]

Jakum Minařík