Circuit Documentation

Summary

This circuit integrates a variety of components including a Raspberry Pi 4B, magnetic encoder, buck converter, motor drivers, display module, fingerprint scanner, distance sensor, temperature sensor, stepper motors, and a power supply. The Raspberry Pi 4B serves as the central processing unit, interfacing with sensors and controlling the stepper motors through the DRV8825 motor drivers. The buck converter steps down the voltage from the power supply to power the Raspberry Pi and other 5V or 3.3V components. The magnetic encoder and distance sensor provide feedback to the Raspberry Pi, while the TM1637 display module and fingerprint scanner serve as the user interface. The DS18B20 temperature sensor provides environmental data. The circuit is powered by a 12V 5A power supply, which is stepped down as needed for various components.

Component List

Raspberry Pi 4B

A microcomputer with multiple GPIO pins used for interfacing with various peripherals and sensors.

AS5600 Magnetic Encoder

A magnetic position sensor that communicates with the Raspberry Pi via I2C protocol.

Buck Converter

A DC-DC converter that steps down voltage from a higher voltage (12V) to a lower voltage to power the Raspberry Pi and other components.

DRV8825

A stepper motor driver capable of driving a bipolar stepper motor.

TM1637

A 4-digit 7-segment display module for displaying information to the user.

Fingerprint Scanner

A biometric sensor used for identification and authentication purposes.

VL53L0Xv2

A time-of-flight distance sensor for accurate distance measurement.

NEMA 17 HS4401

A bipolar stepper motor commonly used for precise motion control.

POWER SUPPLY 12V 5AMP

A power supply unit that provides 12V and 5A to power the circuit.

AC Source

The main AC power source for the circuit.

DS18B20

A digital temperature sensor for measuring ambient temperature.

Resistor

A passive component used to limit current or divide voltages in a circuit.

Wiring Details

Raspberry Pi 4B

• 3V3 connected to VL53L0Xv2 (vcc) and AS5600 Magnetic Encoder (VCC)
• 5V not connected
• GPIO2 (SDA) connected to VL53L0Xv2 (SDA) and AS5600 Magnetic Encoder (SDA)
• GPIO3 (SCL) connected to VL53L0Xv2 (scl) and AS5600 Magnetic Encoder (SCL)
• GND connected to multiple components including Fingerprint Scanner (GND), VL53L0Xv2 (GND), AS5600 Magnetic Encoder (GND), TM1637 (GND), Buck Converter (OUT-), and DS18B20 (GND)
• GPIO4 connected to DS18B20 (signal) through a 4700 Ohm Resistor
• GPIO14 connected to Fingerprint Scanner (TX)
• GPIO15 connected to Fingerprint Scanner (RX)
• GPIO17 connected to DRV8825 (STEP)
• GPIO27 connected to DRV8825 (DIR)
• GPIO22 connected to DRV8825 (STEP)
• GPIO10 connected to DRV8825 (DIR)
• GPIO20 connected to TM1637 (DIO)
• GPIO21 connected to TM1637 (CLK)

AS5600 Magnetic Encoder

• DIR not connected
• SCL connected to Raspberry Pi 4B (GPIO3)
• SDA connected to Raspberry Pi 4B (GPIO2)
• GP0 not connected
• VCC connected to Raspberry Pi 4B (3V3)
• OUT not connected
• GND connected to Raspberry Pi 4B (GND)

Buck Converter

• IN+ connected to POWER SUPPLY 12V 5AMP (12V-24V Output (DC))
• IN- connected to POWER SUPPLY 12V 5AMP (GND (DC))
• OUT+ connected to Fingerprint Scanner (VCC), TM1637 (VCC), DS18B20 (vcc), and Resistor (pin1)
• OUT- connected to Raspberry Pi 4B (GND)

DRV8825

• ENABLE not connected
• MS1, MS2, MS3 not connected
• RESET connected to SLEEP
• SLEEP connected to RESET
• STEP connected to Raspberry Pi 4B (GPIO17 or GPIO22)
• DIR connected to Raspberry Pi 4B (GPIO27 or GPIO10)
• GND connected to Buck Converter (IN-)
• FAULT not connected
• 1B, 1A, 2A, 2B connected to corresponding pins on NEMA 17 HS4401 stepper motors
• VMOT connected to Buck Converter (IN+)

TM1637

• CLK connected to Raspberry Pi 4B (GPIO21)
• DIO connected to Raspberry Pi 4B (GPIO20)
• VCC connected to Buck Converter (OUT+)
• GND connected to Raspberry Pi 4B (GND)

Fingerprint Scanner

• VCC connected to Buck Converter (OUT+)
• TX connected to Raspberry Pi 4B (GPIO14)
• RX connected to Raspberry Pi 4B (GPIO15)
• GND connected to Raspberry Pi 4B (GND)

VL53L0Xv2

• vcc connected to Raspberry Pi 4B (3V3)
• GND connected to Raspberry Pi 4B (GND)
• scl connected to Raspberry Pi 4B (GPIO3)
• SDA connected to Raspberry Pi 4B (GPIO2)
• SPI01, XSHUT not connected

NEMA 17 HS4401

• RED (B2), BLACK (B1), BLUE (A2), GREEN (A1) connected to corresponding pins on DRV8825 motor drivers

POWER SUPPLY 12V 5AMP

• 220V Positive Pole (AC) connected to AC Source (+)
• 220V Negative Pole (AC) connected to AC Source (-)
• GND (DC) connected to Buck Converter (IN-)
• 12V-24V Output (DC) connected to Buck Converter (IN+)

DS18B20

• signal connected to Raspberry Pi 4B (GPIO4) through a 4700 Ohm Resistor
• GND connected to Raspberry Pi 4B (GND)
• vcc connected to Buck Converter (OUT+)

Resistor

• pin1 connected to Buck Converter (OUT+)
• pin2 connected to Raspberry Pi 4B (GPIO4) and DS18B20 (signal)

Documented Code

No code was provided for the microcontrollers in the circuit. Therefore, this section is not applicable for the current documentation.