# MicroPython on ESP32 — system information
import machine
import esp32
import gc

print(f"CPU Frequency: {machine.freq() / 1_000_000} MHz")  # 240 MHz
print(f"Free RAM: {gc.mem_free()} bytes")
print(f"Hall Sensor: {esp32.hall_sensor()} µT")
print(f"Internal Temp: {esp32.raw_temperature()} (raw)")

# Unique chip ID (useful for device identification)
import ubinascii
uid = ubinascii.hexlify(machine.unique_id()).decode()
print(f"Device ID: {uid}")

ESP32 Family
├── ESP32        — Original, dual-core, most libraries
├── ESP32-S2     — Single-core, no BT, more USB features
├── ESP32-S3     — Dual-core, AI accelerator, camera support
├── ESP32-C3     — Single-core RISC-V, very low cost
└── ESP32-C6     — WiFi 6, Zigbee, Thread support

// Arduino Uno — Blink with timing measurement
const int LED_PIN = 13;  // Built-in LED
unsigned long previousMillis = 0;
const long INTERVAL = 1000;  // 1 second

void setup() {
    Serial.begin(9600);
    pinMode(LED_PIN, OUTPUT);
    Serial.println("Arduino Uno ready");
}

void loop() {
    unsigned long currentMillis = millis();

    if (currentMillis - previousMillis >= INTERVAL) {
        previousMillis = currentMillis;

        // Toggle LED without using delay()
        int state = digitalRead(LED_PIN);
        digitalWrite(LED_PIN, !state);

        Serial.print("LED: ");
        Serial.println(state ? "OFF" : "ON");
    }
}

# Python 3 on Raspberry Pi — system info
import subprocess
import os

def get_pi_info():
    # CPU temperature
    temp = subprocess.check_output(['vcgencmd', 'measure_temp']).decode()

    # Free memory
    mem = os.popen('free -m').read().split('\n')[1].split()

    # CPU usage
    cpu = subprocess.check_output(['top', '-bn1']).decode()
    cpu_line = [l for l in cpu.split('\n') if 'Cpu(s)' in l][0]

    return {
        'temperature': temp.strip(),
        'total_mem_mb': mem[1],
        'free_mem_mb': mem[3],
    }

info = get_pi_info()
print(info)
# {'temperature': 'temp=45.1\'C', 'total_mem_mb': '3792', 'free_mem_mb': '2891'}

ESP32 DevKit (38-pin)          Raspberry Pi 4 (40-pin)
┌─────────────────┐            ┌─────────────────┐
│ 3V3  GND        │            │ 3V3  5V         │
│ EN   GPIO 36    │            │ GPIO2 5V        │
│ GPIO 34-39 (IN) │            │ GPIO3 GND       │
│ GPIO 32-33      │            │ GPIO4 GPIO14    │
│ GPIO 25-27      │            │ ...             │
│ GPIO 14-15      │            │ GPIO17-27 ...   │
│ GPIO 12-13      │            │ ADC: NONE       │
│ ADC: 18 channels│            └─────────────────┘
└─────────────────┘

Key difference: Raspberry Pi has NO built-in ADC.
To read analog sensors on Pi, add MCP3008 (SPI) or ADS1115 (I2C).

# Answer these questions to choose your platform

questions = {
    "need_wifi_or_ble": True,
    "need_full_os": False,
    "battery_powered": True,
    "need_camera": False,
    "need_machine_learning": False,
    "beginner": False,
}

def recommend_platform(q):
    if q["need_full_os"] or q["need_camera"] or q["need_machine_learning"]:
        if q["need_machine_learning"]:
            return "NVIDIA Jetson Nano (for AI) or Raspberry Pi 4"
        return "Raspberry Pi 4"

    if q["battery_powered"] and q["need_wifi_or_ble"]:
        return "ESP32 (with deep sleep for long battery life)"

    if q["need_wifi_or_ble"]:
        return "ESP32 (mains powered)"

    if q["beginner"]:
        return "Arduino Uno (no WiFi needed) or ESP32"

    return "Arduino Nano / Uno"

print(recommend_platform(questions))  # ESP32 (with deep sleep)