from machine import Pin, SPI
import utime

# SPI setup for master (RP2040 supports SPI0 and SPI1)
spi_master = SPI(0, sck=Pin(2), miso=Pin(4), mosi=Pin(3), polarity=0, phase=0)
cs = Pin(5, Pin.OUT)  # Chip Select pin

def receive_bits_from_slave():
    cs.value(0)  # Activate slave (CS low)
    utime.sleep_us(10)  # Allow slave to prepare

    received_bits = ""  # Store received 16-bit binary string

    # Send dummy bytes to generate clock and read MISO
    for _ in range(16):
        # Send a dummy byte (0x00) to trigger the clock and receive data
        received_byte = spi_master.read(1)  
        
        # Convert the received byte to a bit
        received_bit = (received_byte[0] & 1)  # Extract LSB
        print("Received bit:", received_bit)

        # Collect bits in a string
        received_bits += str(received_bit)

    cs.value(1)  # Deactivate slave (CS high)

    # Convert the 16-bit binary string to a temperature value
    temperature = int(received_bits, 2) / 100.0

    # Print the full binary and temperature value
    print(f"Complete 16-bit Binary: {received_bits}")
    print(f"Temperature: {temperature:.2f} °C")

while True:
    receive_bits_from_slave()
    utime.sleep(5)  # Wait 5 seconds before the next request

from machine import Pin, SPI, ADC
import utime

# SPI setup for slave (RP2040 supports SPI0 and SPI1)
spi_slave = SPI(1, sck=Pin(18), miso=Pin(16), mosi=Pin(19), polarity=0, phase=0)
cs = Pin(17, Pin.IN, Pin.PULL_UP)  # Chip Select pin

# Internal temperature sensor setup
sensor_temp = ADC(4)  # Use ADC(4) for internal temperature sensor
conversion_factor = 3.3 / 65535
samples = 7

# Median filter to reduce noise
def median_filter_adc():
    readings = [sensor_temp.read_u16() for _ in range(samples)]
    readings.sort()
    return readings[samples // 2]

# Convert temperature to 16-bit binary
def get_temperature_binary():
    median_reading = median_filter_adc()
    voltage = median_reading * conversion_factor
    temperature_c = 27 - (voltage - 0.706) / 0.001721
    # Scale temperature to a 16-bit integer
    temp_16bit = int(temperature_c * 100)  
    print(f"Temperature: {temperature_c:.2f} °C")
    return temp_16bit.to_bytes(2, 'big')  # Convert to 2 bytes (big-endian format)

while True:
    # Wait until CS goes low (start of communication)
    while cs.value(0):
        pass

    # Get the 16-bit temperature value
    temp_binary = get_temperature_binary()

    # Send the 16-bit temperature as 2 bytes
    spi_slave.write(temp_binary)