Hardware Pinout Reference

M5Stack StickC Plus 2 (Stick3) ↔ MCP2515 CAN Bus Module — SPI wiring for Jeep Grand Cherokee OBD-II

3.3 V Logic

M5Stack StickC Plus 2

ESP32-PICO-V3-02 · 3.3 V GPIO

MCU

ESP32-PICO-V3-02

Flash

8 MB

GPIO Voltage

3.3 V

SPI Bus

VSPI / HSPI

WiFi

802.11 b/g/n

USB

Type-C

MCP2515 CAN Bus Module

SPI CAN Controller · TJA1050 Transceiver

Interface

SPI

CAN Spec

2.0A / 2.0B

Max Speed

1 Mbps

Crystal

8 MHz

Supply

3.3 V / 5 V

Transceiver

TJA1050

Physical Pin Identification Guide

The M5Stack StickC Plus 2 has no G-number labels on the hardware. Use the diagrams below to identify each pin by its physical position on the connector.

Bottom HAT Connector — 8-pin header (underside of device)

M5Stack StickC Plus 2

bottom edge (USB-C side faces up)

GND

G26

G36

G25

G37

3V3

← Pin 1 (GND) Pin 8 (3V3) →

Label

GPIO

Description

GND

—

Ground

—

5 V from USB / battery

SPI MOSI — data to MCP2515

G26

SPI CLK — clock signal

G36

SPI MISO — data from MCP2515

G25

SPI CS — chip select (active LOW)

G37

INT — interrupt from MCP2515 (optional)

3V3

—

3.3 V output — power for MCP2515

Grove Port — 4-pin JST connector (right side of device)

Grove Port

GND

G32

G33

Label

GPIO

Description

GND

—

Ground

—

5 V power

G32

Grove SDA / GPIO 32

G33

Grove SCL / GPIO 33

How to orient the connector: Hold the StickC Plus 2 with the screen facing you and the USB-C port at the top. The 8-pin HAT header is on the bottom edge. Pin 1 (GND, black) is on the left, Pin 8 (3V3, red) is on the right. The small triangle or notch on the PCB silkscreen marks Pin 1.

SPI Signal Wiring

M5Stick Pin	Function	MCP2515 Pin	Function	Note
G0	SPI MOSI	SI	MOSI In	Data from M5Stack → MCP2515
G36	SPI MISO	SO	MISO Out	Data from MCP2515 → M5Stack
G26	SPI CLK	SCK	Clock	SPI clock signal
G25	SPI CS	CS	Chip Select	Active LOW — pulled LOW to select MCP2515
G37	INT (optional)	INT	Interrupt	Optional — alerts M5Stack when CAN frame arrives

Power & Ground

M5Stick Pin	Function	Wire	MCP2515 Pin	Function	Note
3V3	3.3 V Out		VCC	Power In	MCP2515 module must be 3.3 V tolerant — check your module
GND	Ground		GND	Ground	Common ground — required

CAN Bus → OBD-II Connector

MCP2515 Module Output

CANHCAN High — connect to Jeep OBD-II pin 6 (CAN High)

CANLCAN Low — connect to Jeep OBD-II pin 14 (CAN Low)

OBD-II J1962 Connector (relevant pins)

Chassis GND

Signal GND

CAN High (HS)

CAN Low (HS)

+12 V Battery

Wiring Overview Diagram

  M5Stack StickC Plus 2                    MCP2515 Module
  ┌─────────────────────┐                  ┌──────────────────┐
  │  G0  (MOSI) ────────┼──── yellow ──────┼── SI             │
  │  G36 (MISO) ────────┼──── blue   ──────┼── SO             │
  │  G26 (CLK)  ────────┼──── orange ──────┼── SCK            │
  │  G25 (CS)   ────────┼──── green  ──────┼── CS             │
  │  G37 (INT)  ────────┼──── purple ──────┼── INT (optional) │
  │  3V3        ────────┼──── red    ──────┼── VCC            │
  │  GND        ────────┼──── black  ──────┼── GND            │
  └─────────────────────┘                  │                  │
                                           │  CANH ───────────┼── OBD-II Pin 6
                                           │  CANL ───────────┼── OBD-II Pin 14
                                           └──────────────────┘

Verify your MCP2515 breakout board operates at 3.3 V. Some modules are 5 V only and will damage the M5Stack GPIO pins.

The MCP2515 requires a crystal oscillator. Most breakout boards include an 8 MHz crystal — set CAN library clock to MCP_8MHZ.

Jeep Grand Cherokee HS-CAN runs at 500 kbps. Set MCP2515 bitrate to CAN_500KBPS in firmware.

The OBD-II port is located under the dashboard on the driver side. Pin 16 is +12 V battery, pin 4/5 are chassis/signal ground.

Use twisted-pair wire for CANH/CANL runs longer than ~10 cm to reduce noise.

The MCP2515 module typically includes a built-in 120 Ω termination resistor. The Jeep bus already has terminators — you may need to remove the module resistor if you see bus errors.

Recommended Arduino/ESP32 library: mcp_can by coryjfowler (GitHub: coryjfowler/MCP_CAN_lib).

Arduino / M5Stack Firmware Snippet

#include <M5StickCPlus2.h>
#include <mcp_can.h>
#include <SPI.h>

#define CAN_CS_PIN  25   // G25
#define CAN_INT_PIN 37   // G37 (optional)

MCP_CAN CAN(CAN_CS_PIN);

void setup() {
  M5.begin();
  SPI.begin(26, 36, 0, 25); // SCK=G26, MISO=G36, MOSI=G0, CS=G25

  if (CAN.begin(MCP_ANY, CAN_500KBPS, MCP_8MHZ) == CAN_OK) {
    Serial.println("MCP2515 init OK");
  }
  CAN.setMode(MCP_NORMAL);
}

void loop() {
  if (CAN.checkReceive() == CAN_MSGAVAIL) {
    long unsigned int rxId;
    unsigned char len;
    unsigned char rxBuf[8];
    CAN.readMsgBuf(&rxId, &len, rxBuf);
    // Process OBD-II frame here
  }
}