Ground Detection

Scenario

During the exploration with the robot, objects located on the surface could be discovered and would trigger a:

• bonus; a special material has been discovered
• damage; a dangerous material might have damaged the robot

Hardware

A NFC module, here RC522, with cards and tags, provide with the module, could be randomly placed on the exploration zone.

The RC522 requires 7 pins for the wiring including 2 for power purposes.

RC522	PICO W
VCC	3v3
RST	PIN0
GND	GND (next to PIN0)
IRQ	-
TX	PIN4
MOSI	PIN3
SCK	PIN2
RX	PIN1

Software

Sources are available on Project Pancake.

The code uses the mfrc522 library, file that need to be copied on the RP2040 for the code to work.

The below code can be added to provide detection of cards and tags. The actual gamification part is not included.

## NFC reader ############################################################
# import NFC reader library
from mfrc522 import MFRC522

# connecting to network 
reader = MFRC522(spi_id=0,sck=2,miso=4,mosi=3,cs=1,rst=0)
previousCard = [0]

def cardReader():
    while True: 
        reader.init()
        (stat, tag_type) = reader.request(reader.REQIDL)
        if uid == previousCard:
            continue
        if stat == reader.OK:
            (stat, uid) = reader.SelectTagSN()
            if stat == reader.OK:
                print("Card detected {}  uid={}".format(hex(int.from_bytes(bytes(uid),"little",False)).upper(),reader.tohexstring(uid)))
                defaultKey = [255,255,255,255,255,255]
                reader.MFRC522_DumpClassic1K(uid, Start=0, End=64, keyA=defaultKey)
                print("Done")
                previousCard = uid
            else:
                pass
        else:
            previousCard = [0]
        utime.sleep_ms(50)