OBD-II / ISO 15765
Araç Teşhis Protokolü

def decode_dtc(b1: int, b2: int) -> str:
    """2 byte DTC'yi P0123 formatına çevir"""
    systems = {0: 'P', 1: 'C', 2: 'B', 3: 'U'}
    system   = systems[(b1 >> 6) & 0x03]
    digit1   = (b1 >> 4) & 0x03   # 0-3
    digit2   = b1 & 0x0F
    digit3   = (b2 >> 4) & 0x0F
    digit4   = b2 & 0x0F
    return ff"{system}{digit1}{digit2:X}{digit3:X}{digit4:X}"

# Örnek: 0x01, 0x13 → P0113 (IAT Sensor High Input)
print(decode_dtc(0x01, 0x13))  # P0113
print(decode_dtc(0x43, 0x02))  # P0302 (Cylinder 2 Misfire)

def decode_supported_pids(data: bytes, base_pid: int = 0x00) -> list:
    """PID 0x00/0x20/0x40 yanıtından desteklenen PID listesi çıkar"""
    bitmap = int.from_bytes(data[:4], 'big')
    supported = []
    for bit in range(32):
        if bitmap & (1 << (31 - bit)):
            supported.append(base_pid + bit + 1)
    return supported

# Örnek yanıt: 0xBE1FA813
pids = decode_supported_pids(bytes([0xBE, 0x1F, 0xA8, 0x13]))
print(", ".join(ff"0x{p:02X}" for p in pids))

PID_DECODERS = {
    0x04: ('Engine Load %',       lambda d: d[0] * 100 / 255),
    0x05: ('Coolant Temp °C',     lambda d: d[0] - 40),
    0x0C: ('Engine RPM',          lambda d: (d[0] * 256 + d[1]) / 4),
    0x0D: ('Vehicle Speed km/h',  lambda d: d[0]),
    0x0F: ('Intake Air Temp °C',  lambda d: d[0] - 40),
    0x10: ('MAF g/s',             lambda d: (d[0] * 256 + d[1]) / 100),
    0x11: ('Throttle %',           lambda d: d[0] * 100 / 255),
    0x2F: ('Fuel Level %',         lambda d: d[0] * 100 / 255),
    0x5C: ('Oil Temp °C',          lambda d: d[0] - 40),
}

def decode_pid(pid: int, raw_data: bytes):
    if pid in PID_DECODERS:
        name, formula = PID_DECODERS[pid]
        value = formula(raw_data)
        print(ff"PID 0x{pid:02X} {name}: {value:.2f}")
    else:
        print(ff"PID 0x{pid:02X}: {raw_data.hex()}")

# ISO-TP kernel modülü yükle
sudo modprobe can-isotp

# Modülün yüklendiğini doğrula
lsmod | grep isotp

# isotp socket kullanımı: isotpsend / isotprecv araçları
# isotp-utils paketi (can-utils ile birlikte gelir)

# OBD Mode 01 PID 0x0C isteği gönder (tek frame)
# TX ID: 0x7DF (broadcast), RX ID: 0x7E8 (engine ECU yanıtı)
sudo isotpsend -s 7DF -d 7E8 can0 <<< "01 0C"

# Yanıt al
sudo isotprecv -s 7E8 -d 7DF can0

import serial, time

class ELM327:
    def __init__(self, port: str, baud: int = 38400):
        self.ser = serial.Serial(port, baud, timeout=2)
        self._init()

    def _init(self):
        self.cmd('AT Z')   # reset
        time.sleep(1)
        self.cmd('AT E0')  # echo off
        self.cmd('AT L0')  # linefeed off
        self.cmd('AT H1')  # headers on
        self.cmd('AT SP 0') # auto protocol

    def cmd(self, command: str) -> str:
        self.ser.write((command + '\r').encode())
        time.sleep(0.1)
        resp = self.ser.read_all().decode('ascii', errors='ignore')
        return resp.strip().rstrip('>').strip()

    def get_rpm(self) -> float:
        resp = self.cmd('01 0C')
        # Yanıt örneği: "7E8 04 41 0C 1A F8"
        parts = resp.split()
        if '41' in parts:
            idx = parts.index('41') + 2  # PID echo sonrası
            return (int(parts[idx], 16) * 256 + int(parts[idx+1], 16)) / 4
        return -1

elm = ELM327('/dev/rfcomm0')  # Bluetooth port
print(ff"RPM: {elm.get_rpm()}")

pip install obd

import obd

# Otomatik port algılamayla bağlan
connection = obd.OBD()   # veya obd.OBD('/dev/rfcomm0')

if connection.is_connected():
    print("OBD-II bağlantısı kuruldu")

# Anlık sorgu
rpm_resp  = connection.query(obd.commands.RPM)
speed_resp = connection.query(obd.commands.SPEED)
temp_resp  = connection.query(obd.commands.COOLANT_TEMP)

if not rpm_resp.is_null():
    print(ff"RPM: {rpm_resp.value.magnitude:.0f}")

if not speed_resp.is_null():
    print(ff"Hız: {speed_resp.value.to('km/h').magnitude:.1f} km/h")

if not temp_resp.is_null():
    print(ff"Soğutucu Sıcaklığı: {temp_resp.value.magnitude:.1f}°C")

connection.close()

import obd, time

# Asenkron bağlantı
connection = obd.Async()

# Callback ile PID izle
def on_rpm(response):
    if not response.is_null():
        print(ff"RPM: {response.value.magnitude:.0f}")

def on_speed(response):
    if not response.is_null():
        print(ff"Hız: {response.value.to('km/h').magnitude:.1f}")

connection.watch(obd.commands.RPM,   callback=on_rpm)
connection.watch(obd.commands.SPEED, callback=on_speed)
connection.start()

time.sleep(30)  # 30 saniye izle
connection.stop()
connection.close()

DTC okuma ve temizleme

import obd

conn = obd.OBD()

# Aktif DTC'leri oku (Mode 03)
dtc_response = conn.query(obd.commands.GET_DTC)
if not dtc_response.is_null():
    for code, desc in dtc_response.value:
        print(ff"DTC: {code}  {desc}")
else:
    print("DTC yok")

# Arıza kodlarını temizle (Mode 04) — DİKKATLİ KULLAN!
# clear_resp = conn.query(obd.commands.CLEAR_DTC)
# if clear_resp.is_null():
#     print("Temizleme başarısız")
# else:
#     print("DTC'ler temizlendi")

conn.close()

Custom command tanımlama

import obd
from obd import OBDCommand
from obd.protocols import ECU
from obd.utils import bytes_to_int

def decode_oil_temp(messages):
    d = messages[0].data[2:]
    if len(d) < 1:
        return obd.OBDResponse()
    temp = bytes_to_int(d) - 40
    return obd.Unit.Quantity(temp, obd.Unit.celsius)

# PID 0x5C: Engine Oil Temperature (Mode 01)
OIL_TEMP = OBDCommand(
    name       = "OIL_TEMP",
    desc       = "Engine Oil Temperature",
    command    = b"\x01\x5C",
    _bytes     = 3,
    decoder    = decode_oil_temp,
    ecu        = ECU.ENGINE,
    fast       = True
)

conn = obd.OBD()
resp = conn.query(OIL_TEMP)
if not resp.is_null():
    print(ff"Motor Yağ Sıcaklığı: {resp.value}°C")
conn.close()

# ISO-TP modülü yükle
sudo modprobe can-isotp

# Araç bağlantısı (OBD konnektör → PEAK PCAN-USB veya MCP2515)
sudo ip link set can0 type can bitrate 500000 restart-ms 100
sudo ip link set can0 up

# RPM sorgusu: Mode 01, PID 0x0C
# TX: 0x7DF broadcast, RX: 0x7E8 (engine ECU yanıtı)
sudo isotpsend -s 7DF -d 7E8 can0 <<< "01 0C"

# Yanıt alma (ayrı terminal)
sudo isotprecv -s 7E8 -d 7DF can0
# Çıktı: 41 0C 1A F8 (41=Mode 01 yanıt, 0C=PID echo, 1AF8=RPM raw)

# DTC sorgusu (Mode 03 — no PID)
sudo isotpsend -s 7DF -d 7E8 can0 <<< "03"

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/socket.h>
#include <linux/can.h>
#include <linux/can/isotp.h>

int main(void) {
    int s = socket(AF_CAN, SOCK_DGRAM, CAN_ISOTP);

    struct sockaddr_can addr;
    memset(&addr, 0, sizeof(addr));
    addr.can_family  = AF_CAN;
    addr.can_addr.tp.tx_id = 0x7DF;  /* OBD broadcast */
    addr.can_addr.tp.rx_id = 0x7E8;  /* Engine ECU yanıtı */
    addr.can_ifindex = if_nametoindex("can0");

    bind(s, (struct sockaddr *)&addr, sizeof(addr));

    /* Mode 01 PID 0x0C isteği */
    uint8_t req[] = {0x01, 0x0C};
    write(s, req, sizeof(req));

    /* Yanıt oku */
    uint8_t resp[8];
    ssize_t len = read(s, resp, sizeof(resp));

    if (len >= 4 && resp[0] == 0x41 && resp[1] == 0x0C) {
        float rpm = ((resp[2] * 256.0f) + resp[3]) / 4.0f;
        printf("Motor Hızı: %.1f RPM\n", rpm);
    }

    close(s);
    return 0;
}

# Bluetooth servis aktif mi?
sudo systemctl status bluetooth

# Bluetooth cihazları tara
sudo bluetoothctl
# power on
# scan on
# pair XX:XX:XX:XX:XX:XX  (ELM327 MAC adresi)
# trust XX:XX:XX:XX:XX:XX

# RFCOMM seri port oluştur
sudo rfcomm bind 0 XX:XX:XX:XX:XX:XX 1
# /dev/rfcomm0 oluştu

# Test
sudo python3 -c "import obd; print(obd.OBD('/dev/rfcomm0').status())"

import obd, time, collections
import matplotlib.pyplot as plt
import matplotlib.animation as animation

MAX_POINTS = 60
rpm_history   = collections.deque(maxlen=MAX_POINTS)
speed_history = collections.deque(maxlen=MAX_POINTS)

conn = obd.Async()
conn.watch(obd.commands.RPM)
conn.watch(obd.commands.SPEED)
conn.start()

fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(10, 6))
fig.suptitle('Araç Verileri — OBD-II')

def update(frame):
    rpm_r   = conn.query(obd.commands.RPM)
    speed_r = conn.query(obd.commands.SPEED)

    if not rpm_r.is_null():
        rpm_history.append(rpm_r.value.magnitude)
    if not speed_r.is_null():
        speed_history.append(speed_r.value.to('km/h').magnitude)

    ax1.clear()
    ax1.plot(list(rpm_history), color='#E74C3C', linewidth=2)
    ax1.set_ylabel('RPM'); ax1.set_ylim(0, 8000)
    ax1.set_title(ff"RPM: {rpm_history[-1]:.0f}" if rpm_history else 'RPM')

    ax2.clear()
    ax2.plot(list(speed_history), color='#2ECC71', linewidth=2)
    ax2.set_ylabel('Hız (km/h)'); ax2.set_ylim(0, 200)
    ax2.set_title(ff"Hız: {speed_history[-1]:.1f} km/h" if speed_history else 'Hız')

ani = animation.FuncAnimation(fig, update, interval=500)
plt.tight_layout()
plt.show()
conn.stop()
conn.close()

import obd

conn = obd.OBD()

# Mode 09 PID 0x02: VIN
vin_resp = conn.query(obd.commands.VIN)
if not vin_resp.is_null():
    vin = vin_resp.value
    print(ff"VIN: {vin}")

    # VIN decode (basit)
    countries = {'1': 'ABD', '2': 'Kanada', '3': 'Meksika',
                 '4': 'ABD', 'J': 'Japonya', 'K': 'Güney Kore',
                 'S': 'İngiltere', 'W': 'Almanya', 'V': 'Fransa'}
    if len(vin) == 17:
        wmi = vin[:3]
        model_year_char = vin[9]
        seq_no = vin[11:]
        country = countries.get(vin[0], 'Bilinmiyor')
        print(ff"Ülke: {country}, WMI: {wmi}, Sıra: {seq_no}")

conn.close()

import obd, time, json, requests

FLEET_API = "https://your-fleet-api.example.com/telemetry"

conn = obd.Async()
conn.watch(obd.commands.RPM)
conn.watch(obd.commands.SPEED)
conn.watch(obd.commands.COOLANT_TEMP)
conn.watch(obd.commands.FUEL_STATUS)
conn.start()

def collect_and_send():
    while True:
        data = {
            'timestamp': time.time(),
            'rpm': None, 'speed_kmh': None,
            'coolant_c': None,
        }

        r = conn.query(obd.commands.RPM)
        if not r.is_null(): data['rpm'] = r.value.magnitude

        r = conn.query(obd.commands.SPEED)
        if not r.is_null(): data['speed_kmh'] = r.value.to('km/h').magnitude

        r = conn.query(obd.commands.COOLANT_TEMP)
        if not r.is_null(): data['coolant_c'] = r.value.magnitude

        try:
            requests.post(FLEET_API, json=data, timeout=2)
        except Exception:
            pass  # bağlantı kesintisinde logla, devam et

        time.sleep(5)   # 5 saniyede bir gönder

collect_and_send()