Embedded Systems projects of Robotics Engineering at the University of Genoa.

The buggy used is a Mikroe Buggy.

All the code was developed in MPLAB X IDE v6.20 using XC16 Compiler. The bootloader used is mikroBootloader USB HID while for serial communication HTERM.

1. Simulate an algorithm that needs 7 ms for its execution, and needs to work at 100 Hz. This is to emulate a real world scenario.
2. Acquire the three magnetometer axes at 25 Hz (set the data rate to 0b110 in the 0x4C register).
3. Do the average of the last 5 measurements.
4. Send it to the UART at 5 Hz using the protocol $MAG,x,y,z*, where x is the average value on the x-axis, y is the average value of the y-axis, and z is the average z-axis value.
5. Compute the angle to the magnetic North using atan2(y avg,x avg).
6. Send the computed angle at 5 Hz using the message $YAW,x*, where x is the angle in degrees.

This project implements a basic control system for an autonomous ground vehicle (buggy). The firmware is responsible for processing movement commands, controlling motors, handling obstacle detection, and monitoring the battery.

• Runs at 1 kHz frequency.

• Controls motors and reads the IR sensor at 1 kHz.

• Starts in "Wait for Start" mode:

  • Motors are off.
  • LED A0 and indicators blink at 1 Hz.

• Transition to "Execute" Mode:

  • Pressing button RE8 moves the system to "Execute" mode.
  • The buggy processes movement commands received via UART.

Commands follow the format: $PCCMD,x,t*

Where:

• x = Motion type
  • 1 → Forward motion
  • 2 → Counterclockwise rotation
  • 3 → Clockwise rotation
  • 4 → Backward motion
• t = Duration (milliseconds)

The system stores commands in a FIFO queue (max 10 commands). If the queue is full, it sends an error message: $MACK,0*

If no commands are available, the buggy remains in the "Execute" state but stops moving.

Uses four PWM signals (10 kHz) for motor control. Pin assignments:

• IR sensor prevents the buggy from getting closer than 20 cm to obstacles.
• Located on Mikrobus 1 or 2 (front of buggy).
• Uses AN14/AN15 for reading and RB9/RA3 for enabling.

• Battery voltage is read from AN11.
• Uses a voltage divider (200kΩ + 100kΩ resistors).

• Command Interface & Data Logging via UART → RS232.

• The microcontroller sends the following data:

• Battery voltage (1 Hz): $MBATT,v_batt*

• Distance sensor reading (10 Hz): $MDIST,distance*

• Uses RD0 (TX) and RD11 (RX).