import machine, os
from machine import Pin, ADC

def printBootInformation():
    # Get operating system information
    info = os.uname()
    # Returns a list of 5 values
    # 0: sysname
    # 1: nodename
    # 2: micropython version
    # 3: micropython version and date
    # 4: machine name
    version = info[3]
    speed = machine.freq() / 1000000

    print("ESP32, micropython {}, frequency, {} MHz".format(version, speed))
    print(" ")
    print("Welcome to Serial console")
    print("Use the help command to know what to do")
    print(" ")

def parseCommand(command):
    # Process led commands 
    # Format: led {on | off} { pin# }
    if ("led" in command):
        cmd_parts = command.split(" ")
        if (len(cmd_parts) == 3 and cmd_parts[0] == "led"):
            led_pin = int(cmd_parts[2])
            led = Pin(led_pin, Pin.OUT)
            if (cmd_parts[1] == "on"):
                led.value(1)
                return [True, "ok"]
            elif (cmd_parts[1] == "off"):
                led.value(0)
                return [True, "ok"]
    # Process adc commands 
    # Format: adc {read | voltage} { pin# }
    elif ("adc" in command):
        cmd_parts = command.split(" ")
        if (len(cmd_parts) == 3 and cmd_parts[0] == "adc"):
            adc_pin = int(cmd_parts[2])
            adc = ADC(Pin(adc_pin))
            if (cmd_parts[1] == "read"):
                return [True, adc.read()]
            elif (cmd_parts[1] == "voltage"):
                raw_value = adc.read()
                # Use formula: V = raw_value * 3.3V / 4096
                voltage = raw_value * 3.3 / 4096
                return [True, "{:.2f}V".format(voltage)]
    # Process help command
    elif ("help" in command):
        # Just print a help
        print("Available commands: led, adc")
        print(" ")
        print("led: Turns on or off an led on the provided pin")
        print("Format: led { on | off } { pin } ")
        print("Return: ok if success")
        print(" ")
        print("adc: Read the adc value in raw or voltage")
        print("Format: adc { read | voltage } { pin } ")
        print("Return: ADC raw value or volage value (in volts)")
        return [True, " "]
     # In any other cases, the command is invalid, return false 
    return [False]
            
   # Program starts here
printBootInformation()

while True:
    command = input("> ")
    result = parseCommand(command)
    if (not result[0]):
        print("invalid command")
    else:
        print(result[1])