print("Hello, ESP32!")


'''
 # Demonstrates ESP32 interface to MicroSD Card Adapter
 # Create a text file and write running numbers.
 # Open text file, read and print the content on debug port
   
 * The ESP32 pin connections for MicroSD Card Adapter SPI
 
 # MicroSD Card Adapter Power Pins
 * MicroSD VCC pin to ESP32 +5V
 * MicroSD GND pin to ESP32 GND
 
 # MicroSD SPI Pins
 * MicroSD MISO pin to ESP32 GPIO13
 * MicroSD MOSI pin to ESP32 GPIO12
 * MicroSD SCK pin to ESP32 GPIO14
 * MicroSD CS pin to ESP32 GPIO27
 
 Name:- M.Pugazhendi
 Date:-  20thOct2021
 Version:- V0.1
 e-mail:- [email protected]
'''
import machine
from machine import Pin, SPI, SoftSPI
import sdcard
import os
 
toggle = 0
 
#Initialize the onboard LED as output
led = machine.Pin(2,machine.Pin.OUT)

# Toggle LED functionality
def BlinkLED(timer_one):
    global toggle
    if toggle == 1:
        led.value(0)
        toggle = 0
    else:
        led.value(1)
        toggle = 1

# BJMing Doc ########
# MicroSD Card FAT32 Block Size 512 byte
# MicroSD Pin-Connection
# DO => PIN(D12)
# SCK => PIN(D14)
# DI => PIN(D13)
# CS => PIN(D27)
# GND => GND
# VCC => 3.3Vdc
# BJMing Doc ########

# Initialize the SD card
spi=SoftSPI(1,sck=Pin(14),mosi=Pin(13),miso=Pin(12))
sd=sdcard.SDCard(spi,Pin(27))

# Create a instance of MicroPython Unix-like Virtual File System (VFS),
vfs=os.VfsFat(sd)
 
# Mount the SD card
os.mount(sd,'/sd')

# Debug print SD card directory and files
print(os.listdir('/sd'))

# Create / Open a file in write mode.
# Write mode creates a new file.
# If  already file exists. Then, it overwrites the file.
file = open("/sd/sample.txt","w")

# Write sample text
for i in range(20):
    file.write("Sample text = %s\r\n" % i)
    
# Close the file
file.close()

# Again, open the file in "append mode" for appending a line
file = open("/sd/sample.txt","a")
file.write("Appended Sample Text at the END \n")
file.close()

# Open the file in "read mode". 
# Read the file and print the text on debug port.
file = open("/sd/sample.txt", "r")
if file != 0:
    print("Reading from SD card")
    read_data = file.read()
    print (read_data)
file.close()

# Initialze timer_one. Used for toggling the on board LED
timer_one = machine.Timer(0)

# Timer one initialization for on board blinking LED at 200mS interval
timer_one.init(freq=5, mode=machine.Timer.PERIODIC, callback=BlinkLED)