Raspberry Pi B+:

The Raspberry Pi 3 Model B+ is the final revision in the Raspberry Pi 3 range.

• Broadcom BCM2837B0, Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz
• 1GB LPDDR2 SDRAM
• 2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2, BLE
• Gigabit Ethernet over USB 2.0 (maximum throughput 300 Mbps)
• Extended 40-pin GPIO header
• Full-size HDMI
• 4 USB 2.0 ports
• CSI camera port for connecting a Raspberry Pi camera
• DSI display port for connecting a Raspberry Pi touchscreen display
• 4-pole stereo output and composite video port
• Micro SD port for loading your operating system and storing data
• 5V/2.5A DC power input
• Power-over-Ethernet (PoE) support (requires separate PoE HAT)

Although we could choose a basic Arduino microcontroller to do all the connectivity and programming between these basic sensors. Reason to choose this over Arduino is that future expansion of on-board sensors will allow us to better view, control, and program them by connecting the robot wireless using ssh terminal. Reprogramming won't demand physical connection. Furthermore, all necessary indoor communication modules (Bluetooth and WiFi) are installed on board, which saves us space and hassle of connection.

Linux operating allows the flexibility to modify operating to custom requirements. It also allows us to use python and C to directly communicate with sensors and actuators, which can then be used to apply plethora tools to analyze the data using machine learning algorithms. Logged data can then be used to train models which can then be directly executed on Raspberry Pi.

DRV8825 Stepper Motor Driver

The DRV8825 stepper motor driver has output drive capacity of up to 45V and lets you control one bipolar stepper motor at up to 2.2A output current per coil. The driver has built-in translator for easy operation. This reduces the number of control pins to just 2, one for controlling the steps and other for controlling spinning direction.

Features:

• Six step resolution: Full step, ½ step, ¼ step, 1/8, 1/16 and 1/32 step
• Adjustable output current via potentiometer
• Automatic current decay mode detection
• Over temperature shutdown circuit
• Under-voltage lock out
• Over current shutdown

________________________________________________________________

Inertial Measurement Unit:

The MPU 9250 object reads acceleration, angular velocity, and magnetic field using the InvenSense MPU-9250 sensor. The MPU-9250 is a 9 degree of freedom (DOF) inertial measurement unit (IMU) used to read acceleration, angular velocity, and magnetic field in all three dimensions.

________________________________________________________________

Magnatometer:

The 3-Axis Digital Compass HMC5883L sensor is able to acquire information even in a low magnetic field. Distributed over the three axes, this information is converted into a differential voltage of 2.7 to 6.5 VDC to provide input for a vast range of microcontrollers operating at different voltages.

The raw digital output value can be used to calculate direction and location, and for measuring both the magnitude and the direction of the Earth’s magnetic field in cases where the robot needs to measure several magnetic fields coming from different directions.

________________________________________________________________

Protoboard:

An empty canvas for electrical enthusiasts

________________________________________________________________

Digital Voltmeter:

_

Technical Parameters: 

Dimension: 48×29×22mm  

Cutting size: 46×27mm  

Measuring voltage range: DC 3-30V  

Maximum input: DC 30V (if the input voltage is higher than DC30V, the voltmeter will be burnt)  

Minimum input: DC 3V (if the input voltage is lower than DC 3V, the value will be inaccurate or not displayed)  

Measurement accuracy: Less than 10V, accurate to 0.01V; More than 10V, accurate to 0.1V (allowable tolerance: 1% +/- 1 word)  

Display: 3 digit 0.56'' LED digital tube 

Font Color: Green  

Refresh rate: about 200mS  

No need power supply  

Consuming current: less than 20mA (generally 5-15mA)  

Operating temperature: -10°c-65°c 

Wire length: 20cm  

Reverse connection protection: YES  

Method of wiring:  Red wire: Positive  

Black wire: Negative 

________________________________________________________________

Writing 3 bit binary code on pins M0, M1, M2 allow for change in micro-step resolution. This is results in overall fine control of the motion of the robot.

The STEP Pin input controls the micro-steps of the motor. Each HIGH pulse sent to this pin steps the motor by number of micro-steps set by Micro-step Selection Pins. The higher the frequency, the higher the rotational speed of the motor.

The DIR pin input controls the spinning direction of the motor. Pulling it HIGH drives the motor clockwise and pulling it LOW drives the motor counterclockwise.