Miki - micromouse

### DESCRIPTION ( Introduce yourserlf and your project)

My name is Marcin, my last idea was to design a prototype micromouse robot. These robots move in the maze. The maze consists of squares 18cm x 18cm. The robot must be small, fast and agile. Professional constructions use two electric motors driving four wheels. Due to little experience, the first test was made with N20 motors with a ratio of 30: 1.

The robot shown in the pictures was named Miki. Very efficiently drives the maze using the flood-fill algorithm. It allows you to generate a path in a known labyrinth. This is the shortest possible path. The algorithm itself is quite complicated, but it is quick and convenient to implement in the robot.

### TECHNICAL DETAILS (With project photos)

A mobile robot consists of two main harmonizing parts:

• electronic;

• mechanical.

The STM32F103RBT6 microcontroller from STMicroelectronics based on the ARM Cortex M3 core, equipped with 128 kB FLASH memory and 20kB RAM, was used as the basis for the construction of the electronic part. The maximum clock speed is 72MHz. It forms the basis connecting all other components, such as:

• SCT2026 - IR LED controller;

• TB6612FNG - the H driver bridge;

• MiniIMU module - gyroscope, accelerometer and magnetometer;

• AS5306 - magnetic encoder;

• 24AA01 - EEPROM memory.

    In order to determine the exact current of the IR LEDs, a special LED driver SCT2026 from StarChips was used to communicate using the SPI bus. It has 16 input channels with a selectable constant current of 5 to 90mA. The motor controller commonly referred to as the H bridge is the Toshiba TB6612FNG system. This model has two channels with a maximum current current of 1.2A, maximum instantaneous current up to 3.2A and a voltage supplying motors up to 15V. As a gyroscope, accelerometer and magnetometer, a Pololu module called MinIMU-9 in version 5 was used, which communicates using the I2C interface. It contains two sensors LSM6DS33 and LIS3MD from STMicroelectronics. The robot has been equipped with AS5306A encoders of the Austrian company AMS. The maximum possible resolution is 160 steps per magnetic field transmitted in quadrature mode with an optional index. STM32Fx microcontrollers do not have EEPROM memory, so an additional memory has been used that uses the I2C bus for communication. The platform based on a PCB board, on which all necessary electronic and mechanical elements will be placed, will be responsible for the running platform. As a drive, Polbank's HPP (High-Power Carbon Brush) with a 30: 1 gearing with a rated voltage of 6V was used. Rims and tires are a ready element available in Polol's products. Magnetic encoders require very close to the dedicated magnet. For this purpose, a 72-field 32-mm magnetic ring was used for the above-mentioned integrated circuit. It was attached directly to the rim.

Due to the small size of the PCB, a very small 6-mile path was used. Thanks to PCBway, it was possible to make such a small plate with 0.3mm guides. Great workmanship allowed for easy soldering. Cutting holes is perfectly made.

### Words to PCBWay

To develop a robotics project, I often need PCBs for microcontrollers and other electronic circuits. I would like to build with you some more complicated robots, but without your help it will not work.

In gratitude I will do everything in our power to advertise PCBWay, where we can ever, for example, on groups on facebook.