Circuit Documentation

Summary

This circuit integrates an Arduino Nano microcontroller with an MCP2515 CAN controller, a 7805 voltage regulator, an ST7735 TFT display, a pushbutton, a resistor, and an OBD-II port. The circuit is designed to interface with a vehicle's OBD-II port, display information on the TFT screen, and allow user interaction through the pushbutton.

Component List

Arduino Nano

• Description: A small, complete, and breadboard-friendly board based on the ATmega328P.
• Pins: D1/TX, D0/RX, RESET, GND, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11/MOSI, D12/MISO, VIN, 5V, A7, A6, A5, A4, A3, A2, A1, A0, AREF, 3V3, D13/SCK

MCP2515

• Description: A CAN controller with SPI interface.
• Pins: INT, SCK, SI, SO, CS, GND, VCC, H, L

7805

• Description: A voltage regulator that outputs a stable 5V.
• Pins: Vin, Gnd, Vout

ST7735 128x128 1.44 TFT I2C Color

• Description: A 1.44-inch TFT display with I2C interface.
• Pins: BL, C5, DC, RES, SDA, SCL, GND, VCC

Resistor

• Description: A 120 Ohm resistor.
• Pins: pin1, pin2
• Properties: Resistance: 120 Ohms

OBD-II port

• Description: A standard OBD-II port for vehicle diagnostics.
• Pins: 12v, GND, CANH, CANL

Pushbutton

• Description: A simple pushbutton for user input.
• Pins: Pin 2, Pin 1, Pin 3, Pin 4

Wiring Details

Arduino Nano

• GND connected to the common ground.
• D2 connected to INT of MCP2515.
• D4 connected to Pin 4 of Pushbutton.
• D6 connected to C5 of ST7735 TFT.
• D7 connected to DC of ST7735 TFT.
• D8 connected to RES of ST7735 TFT and SI of MCP2515.
• D10 connected to CS of MCP2515.
• D12/MISO connected to SO of MCP2515.
• D13/SCK connected to SCK of MCP2515 and SCL of ST7735 TFT.
• VIN connected to Vout of 7805.

MCP2515

• GND connected to the common ground.
• INT connected to D2 of Arduino Nano.
• SCK connected to D13/SCK of Arduino Nano and SCL of ST7735 TFT.
• SI connected to RES of ST7735 TFT and D8 of Arduino Nano.
• SO connected to D12/MISO of Arduino Nano.
• CS connected to D10 of Arduino Nano.
• VCC connected to Vout of 7805.
• H connected to CANH of OBD-II port and pin1 of Resistor.
• L connected to CANL of OBD-II port and pin2 of Resistor.

7805

• Gnd connected to the common ground.
• Vout connected to VCC of MCP2515, BL and VCC of ST7735 TFT, and VIN of Arduino Nano.
• Vin connected to 12v of OBD-II port.

ST7735 128x128 1.44 TFT I2C Color

• GND connected to the common ground.
• BL connected to Vout of 7805.
• C5 connected to D6 of Arduino Nano.
• DC connected to D7 of Arduino Nano.
• RES connected to SI of MCP2515 and D8 of Arduino Nano.
• SDA not connected.
• SCL connected to SCK of MCP2515 and D13/SCK of Arduino Nano.
• VCC connected to Vout of 7805.

Resistor

• pin1 connected to CANH of OBD-II port and H of MCP2515.
• pin2 connected to CANL of OBD-II port and L of MCP2515.

OBD-II port

• GND connected to the common ground.
• 12v connected to Vin of 7805.
• CANH connected to H of MCP2515 and pin1 of Resistor.
• CANL connected to L of MCP2515 and pin2 of Resistor.

Pushbutton

• Pin 1 connected to the common ground.
• Pin 4 connected to D4 of Arduino Nano.

Documented Code

Arduino Nano Code (sketch.ino)

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

Additional Documentation (documentation.txt)

This documentation provides a comprehensive overview of the circuit, including a detailed component list, wiring details, and the code used in the Arduino Nano microcontroller.