{"title":"RFID \u0026 NFC Modules","description":"\u003cp\u003eRFID and NFC modules read the ID from a card or tag held near them. That ID drives door locks, attendance registers and access-control projects.\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eRC522 (MFRC522)\u003c\/strong\u003e is the common choice:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eit reads 13.56 MHz tags over SPI;\u003c\/li\u003e\n\u003cli\u003ethe tags are passive, powered by the reader's field;\u003c\/li\u003e\n\u003cli\u003erange is about 5 cm.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe RC522 runs on 3.3V only, and 5V will damage it. On a 5V Arduino, power it from the 3.3V pin and use a level shifter on the SPI lines. On an ESP32 it wires directly, because the pins are already 3.3V.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ePick the RC522 for 13.56 MHz cards, fobs and MIFARE tags.\u003c\/li\u003e\n\u003cli\u003ePick a 125 kHz reader for EM4100-style fobs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eOne common surprise: 125 kHz tags (often EM4100 key fobs) will not read on the RC522. They need a 125 kHz reader such as the JT308 USB reader.\u003c\/p\u003e\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eCan I power the RC522 from 5V?\u003c\/h3\u003e\n\u003cp\u003eNo. Use 3.3V, and a level shifter on the SPI data lines with a 5V board.\u003c\/p\u003e\n\u003ch3\u003eWhy won't my key fob read?\u003c\/h3\u003e\n\u003cp\u003eIt is probably a 125 kHz tag. The RC522 reads 13.56 MHz tags only; use a 125 kHz reader.\u003c\/p\u003e\n\u003ch3\u003eWhich cards work with the RC522?\u003c\/h3\u003e\n\u003cp\u003e13.56 MHz MIFARE Classic cards and key fobs. 125 kHz EM4100 tags need a 125 kHz reader.\u003c\/p\u003e\n\u003ch3\u003eHow far can it read?\u003c\/h3\u003e\n\u003cp\u003eThe RC522 reads passive tags at about 5 cm.\u003c\/p\u003e\n\u003ch2\u003eGuides\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/guides\/rc522-rfid-arduino-wiring-passive-tags\"\u003eRC522 RFID with Arduino: Wiring \u0026amp; What Passive Means\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/guides\/how-to-build-rfid-attendance-system\"\u003eHow to Build an RFID Attendance System\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/guides\/how-to-make-an-rfid-door-lock\"\u003eHow to Make an RFID Door Lock\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Can I power the RC522 from 5V?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No. Use 3.3V, and a level shifter on the SPI data lines with a 5V board.\"}}, {\"@type\": \"Question\", \"name\": \"Why won't my key fob read?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is probably a 125 kHz tag. The RC522 reads 13.56 MHz tags only; use a 125 kHz reader.\"}}, {\"@type\": \"Question\", \"name\": \"Which cards work with the RC522?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"13.56 MHz MIFARE Classic cards and key fobs. 125 kHz EM4100 tags need a 125 kHz reader.\"}}, {\"@type\": \"Question\", \"name\": \"How far can it read?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The RC522 reads passive tags at about 5 cm.\"}}]}\u003c\/script\u003e","products":[{"product_id":"elecrow-crowtail-nfc-20-rfid-reader-module-arduino-iot","title":"Elecrow Crowtail NFC 2.0 RFID Reader Module - Arduino \u0026 IoT","description":"\u003ch1\u003eElecrow Crowtail NFC 2.0 RFID Reader Module - Read\/Write 13.56MHz NFC Tags\u003c\/h1\u003e\n\n\u003cp\u003eThe Elecrow Crowtail NFC 2.0 is an RFID reader module based on the PN532 chip, designed for easy integration with Arduino, ESP32, Raspberry Pi, and other IoT platforms. It supports reading and writing of 13.56MHz NFC tags including MIFARE, NTAG, and FeliCa. The Crowtail connector allows plug-and-play connection without soldering, making it ideal for prototyping access control systems, interactive installations, and contactless payment solutions.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eChipset\u003c\/td\u003e\n\u003ctd\u003eNXP PN532\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Voltage\u003c\/td\u003e\n\u003ctd\u003e3.3V\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCommunication Interfaces\u003c\/td\u003e\n\u003ctd\u003eI2C, SPI, UART (selectable)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Frequency\u003c\/td\u003e\n\u003ctd\u003e13.56 MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRead\/Write Distance\u003c\/td\u003e\n\u003ctd\u003eUp to 5 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSupported Standards\u003c\/td\u003e\n\u003ctd\u003eISO\/IEC 14443 A\/B, FeliCa, NFCIP-1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-servo-door-lock\"\u003eNFC door lock using an Arduino and solenoid\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003eContactless attendance system for schools or offices\u003c\/li\u003e\n  \u003cli\u003eMobile payment terminal prototype with a screen\u003c\/li\u003e\n  \u003cli\u003eInteractive product display that reads NFC tags to show info\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eThis module is compatible with any microcontroller that supports I2C, SPI, or UART communication. It works seamlessly with Arduino Uno, Mega, Nano, ESP8266, ESP32, and Raspberry Pi. The working voltage is 3.3V; for 3.3V boards, no level shifting is needed.\u003c\/p\u003e\n\n\u003ch2\u003eWiring Notes\u003c\/h2\u003e\n\u003cp\u003eFor I2C connection (default), connect the module's VCC to 3.3V, GND to GND, SDA to SDA, and SCL to SCL. Ensure the I2C pull-up resistors are present (usually internal on Arduino boards). If using SPI, select the SS pin accordingly.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-7 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino Uno?\u003c\/summary\u003e\u003cp\u003eYes, the Crowtail NFC 2.0 works with Arduino Uno out of the box. Connect via I2C using the provided Crowtail cable to the corresponding I2C pins (A4 for SDA, A5 for SCL).\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan it write data to NFC tags?\u003c\/summary\u003e\u003cp\u003eAbsolutely. The PN532 chip supports read and write operations for most NFC tag types, including NTAG215 and MIFARE Classic, using libraries like Adafruit PN532.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat is the maximum reading distance?\u003c\/summary\u003e\u003cp\u003eThe typical reading distance is 3–5 cm, depending on the tag size and antenna design. For optimal performance, ensure no metal objects are behind the tag.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53444946035053,"sku":"CDN-0038","price":1530.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/elecrow-crowtail-nfc-20-rfid-reader-module-arduino-iot-6185672.jpg?v=1790780347"},{"product_id":"jt308-125khz-usb-proximity-sensor-rfid-reader-module","title":"JT308 125KHz USB Proximity Sensor RFID Reader Module","description":"\u003ch1\u003eJT308 125KHz USB Proximity Sensor RFID ID Card Reader Module\u003c\/h1\u003e\n\n\u003cp\u003eThe JT308 is a 125KHz USB proximity sensor RFID reader module that decodes standard EM4100 protocol tags and outputs the ID as keyboard keystrokes over USB. It is used for building access control systems, attendance trackers, and interactive projects. No driver installation is required—just plug it into any USB host and it behaves like a keyboard.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Frequency\u003c\/td\u003e\n\u003ctd\u003e125KHz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eProtocol\u003c\/td\u003e\n\u003ctd\u003eEM4100 (125kHz)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eInterface\u003c\/td\u003e\n\u003ctd\u003eUSB 1.1\/2.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOutput Format\u003c\/td\u003e\n\u003ctd\u003e10 decimal digits + enter (keyboard)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRead Range\u003c\/td\u003e\n\u003ctd\u003eUp to 5 cm (depends on tag)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSupply Voltage\u003c\/td\u003e\n\u003ctd\u003e5V DC via USB\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eDIY access control system\u003c\/li\u003e\n  \u003cli\u003eAttendance logger with Raspberry Pi\u003c\/li\u003e\n  \u003cli\u003eInventory tracking of tagged items\u003c\/li\u003e\n  \u003cli\u003eInteractive exhibition with tag triggers\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eWorks with any USB host that supports keyboard input—Windows, Mac, Linux, Raspberry Pi, and microcontrollers with USB host shields (like Arduino USB Host Shield). It draws power from the USB port (5V) and outputs standard key strokes, so no libraries are needed.\u003c\/p\u003e\n\n\u003ch2\u003eWiring Notes\u003c\/h2\u003e\n\u003cp\u003eNo external wiring is needed; simply plug the module into a USB port. The device enumerates as a HID keyboard. Ensure the USB host supplies 5V and sufficient current (50mA typical).\u003c\/p\u003e\n\n\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-7 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eIs this compatible with Raspberry Pi?\u003c\/summary\u003e\u003cp\u003eYes, it works as a keyboard input device when connected via USB. You can read tag data using any program that accepts keyboard input.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan it read 13.56MHz NFC cards?\u003c\/summary\u003e\u003cp\u003eNo, this reader operates at 125kHz and is designed for EM4100 protocol only. For NFC, consider a PN532 module.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat tags work with this reader?\u003c\/summary\u003e\u003cp\u003eIt works with standard 125kHz EM4100 frequency RFID tags and key fobs commonly used for access control. We also sell compatible tags separately.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53444954063213,"sku":"CDN-0238","price":430.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/jt308-125khz-usb-proximity-sensor-rfid-reader-module-3699774.jpg?v=1790780227"},{"product_id":"mfrc522-1356mhz-rfid-readerwriter-module-for-arduino","title":"MFRC522 13.56MHz RFID Reader\/Writer Module for Arduino","description":"\u003ch1\u003eMFRC522 13.56MHz RFID Reader\/Writer Module with SPI Interface\u003c\/h1\u003e\n\n\u003cp\u003eThe MFRC522 RFID module is a compact 13.56MHz contactless reader\/writer based on the NXP MFRC522 IC. It supports ISO\/IEC 14443 A\/MIFARE and NTAG tag types, making it ideal for access control, attendance systems, and IoT projects. With SPI communication, it easily connects to popular microcontrollers for reading and writing NFC tags.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Frequency\u003c\/td\u003e\n\u003ctd\u003e13.56 MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCommunication Interface\u003c\/td\u003e\n\u003ctd\u003eSPI (up to 10 Mbps)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSupported Tag Types\u003c\/td\u003e\n\u003ctd\u003eMIFARE Classic, MIFARE Ultralight, NTAG2xx\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Voltage\u003c\/td\u003e\n\u003ctd\u003e2.5V - 3.6V (3.3V typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRead Range\u003c\/td\u003e\n\u003ctd\u003eUp to 5 cm (with included antenna)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCurrent Consumption\u003c\/td\u003e\n\u003ctd\u003e13-26 mA (typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-arduino-rfid-door-lock\"\u003eRFID door lock with solenoid or servo control\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003eAutomated attendance system logging card UIDs\u003c\/li\u003e\n  \u003cli\u003eSmart inventory tracker with tagged items\u003c\/li\u003e\n  \u003cli\u003eContactless payment terminal using MIFARE wallets\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eWorks with Arduino (Uno, Mega, Nano via SPI), Raspberry Pi (enable SPI interface), and ESP8266\/ESP32. The module requires 3.3V power and logic; for 5V systems, use level shifters or a 3.3V-compatible breakout. Pairs well with the MFRC522 library for Arduino and the Pi mfrc522 Python package.\u003c\/p\u003e\n\n\u003ch2\u003eWiring Notes\u003c\/h2\u003e\n\u003cp\u003eConnect SDA to SS (CS), SCK to SCK, MOSI to MOSI, MISO to MISO, and RST to a digital pin. The IRQ pin is optional. Always provide 3.3V to VCC and ensure all logic signals are at 3.3V to prevent damage.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-7 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino Uno?\u003c\/summary\u003e\u003cp\u003eYes, it works with Arduino Uno using the SPI pins (10-13) and the MFRC522 library. However, the module is 3.3V — use level shifters on the SPI lines if powering from 5V, or opt for a 3.3V-tolerant board.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes it work with Raspberry Pi?\u003c\/summary\u003e\u003cp\u003eYes, enable SPI via raspi-config and use the mfrc522 Python library. Connect to the Pi’s 3.3V supply and SPI pins; no level shifting needed.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat tags are included?\u003c\/summary\u003e\u003cp\u003eThe module is sold without tags. Compatible tags include MIFARE Classic 1K\/4K, Ultralight, and NTAG213\/215\/216. Most common RFID cards and key fobs based on these standards will work.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53445070422381,"sku":"CDN-0908","price":180.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/mfrc522-1356mhz-rfid-readerwriter-module-for-arduino-4918375.jpg?v=1790779687"},{"product_id":"rfid-cards-1356mhz-mifare-classic-pack-of-5-for-mfrc522","title":"RFID Cards 13.56MHz MIFARE Classic – Pack of 5 for MFRC522","description":"\u003ch1\u003eRFID Cards 13.56MHz MIFARE Classic – Pack of 5 for MFRC522\u003c\/h1\u003e\n\n\u003cp class=\"product-lede\"\u003eThese 13.56MHz MIFARE Classic RFID cards come in a pack of five, designed to work seamlessly with the popular MFRC522 reader module for Arduino, ESP32, and Raspberry Pi projects.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable class=\"specs-table\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003eFrequency\u003c\/th\u003e\n\u003ctd\u003e13.56 MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eProtocol\u003c\/th\u003e\n\u003ctd\u003eISO 14443A\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eChip\u003c\/th\u003e\n\u003ctd\u003eMIFARE Classic 1K\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eMemory\u003c\/th\u003e\n\u003ctd\u003e1 KB (16 sectors × 4 blocks)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eData Retention\u003c\/th\u003e\n\u003ctd\u003e10 years\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eWrite Endurance\u003c\/th\u003e\n\u003ctd\u003e~100,000 cycles\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eRead Range\u003c\/th\u003e\n\u003ctd\u003eUp to 10 cm (with MFRC522)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eDimensions\u003c\/th\u003e\n\u003ctd\u003e85.6 × 54 mm (CR80)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-arduino-rfid-door-lock\"\u003e\n\u003cstrong\u003eRFID Door Lock:\u003c\/strong\u003e Use an Arduino Uno with MFRC522 to unlock a door when a matching card is scanned.\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/rfid-attendance-system-kit-log-cards-to-sd-python-weekly-reports\"\u003e\n\u003cstrong\u003eIoT Attendance Logger:\u003c\/strong\u003e Log student attendance by scanning RFID cards and send data to a cloud spreadsheet via ESP32.\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLibrary Self-Checkout:\u003c\/strong\u003e Build a kiosk with Raspberry Pi and RFID to track borrowed books in real time.\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/rfid-attendance-system-kit-log-cards-to-sd-python-weekly-reports\"\u003e\n\u003cstrong\u003eSmart Classroom Attendance:\u003c\/strong\u003e An RFID-based attendance recorder for CBSE practicals or ATL Tinkering Lab demonstrations.\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/learn-authentication-build-an-rfid-access-control-system-kit-with-arduin\"\u003e\n\u003cstrong\u003eMulti-factor Authentication:\u003c\/strong\u003e Combine RFID card scan with PIN entry on ESP32 for a secure access control system.\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003ctable class=\"compat-table\"\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003ePlatform\u003c\/th\u003e\n\u003cth\u003eCompatible\u003c\/th\u003e\n\u003cth\u003eConnection\u003c\/th\u003e\n\u003cth\u003eLibrary \/ Method\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Uno R3\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522 library\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Nano\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522 library\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Mega 2560\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522 library\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eESP8266 NodeMCU\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522 library\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eESP32 Dev Board\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522 library\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRaspberry Pi Pico\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522-pico library\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRaspberry Pi 4 \/ 5\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eSPI via MFRC522\u003c\/td\u003e\n\u003ctd\u003eMFRC522-python library\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWiring and Interface Notes\u003c\/h2\u003e\n\u003cp\u003eConnect the MFRC522 reader to your microcontroller using SPI: typically wire SS to pin 10, RST to 9, SCK to 13, MOSI to 11, and MISO to 12 on an Arduino Uno. The cards are passive, requiring no power—simply hold them near the reader to read or write data. For platforms like Raspberry Pi, enable SPI in settings and use the corresponding MFRC522 Python library.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"faq\"\u003e\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003ch3\u003eHow do I write data to these MIFARE Classic cards?\u003c\/h3\u003e\n    \u003cp\u003eYou can write up to 1KB of data using the MFRC522 library’s write functions, but each sector must be authenticated with a key first. Default keys are often FFFFFFFFFFFF for unused cards.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003ch3\u003eCan these cards be used for long-range identification?\u003c\/h3\u003e\n    \u003cp\u003eNo, the maximum read range is about 10 cm with the MFRC522 reader. For longer range, consider UHF RFID tags.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53454858355053,"sku":"CDN-0974","price":75.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/rfid-cards-1356mhz-mifare-classic-pack-of-5-for-mfrc522-1329525.jpg?v=1790779386"},{"product_id":"rfid-125khz-card-tag","title":"125KHz RFID Card Tag (EM4100 Proximity)","description":"\u003ch1\u003e125KHz RFID Card Tag (EM4100 Proximity)\u003c\/h1\u003e\n\u003cp\u003eA 125KHz proximity RFID card tag (EM4100-compatible) with a fixed, read-only UID. It is the standard low-frequency card for access control, attendance, and identification projects, and pairs with any 125KHz reader.\u003c\/p\u003e\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e125KHz readers such as the JT308, RDM6300 and EM-18\u003c\/li\u003e\n  \u003cli\u003eArduino, ESP32 and Raspberry Pi via a 125KHz reader module\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eBuild it with Compoden's AI\u003c\/h2\u003e\u003cp\u003ePairing a tag with the right reader and code trips up a lot of first builds. Describe your access-control or attendance project to Compoden's AI build assistant. It matches the tag to a compatible reader at the same frequency, checks every part against real stock, and hands you the wiring and the code.\u003c\/p\u003e\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eWe have spent 10 years supplying RFID, electronics, and robotics parts to makers, schools, and access-control projects across India. Every Compoden order includes our AI build companion to help you wire the reader, write the code, and get the tag reading on the first try.\u003c\/p\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat frequency is this tag?\u003c\/summary\u003e\u003cp\u003e125KHz, EM4100 protocol - a read-only card with a fixed UID.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes it work with the MFRC522?\u003c\/summary\u003e\u003cp\u003eNo. The MFRC522 is a 13.56MHz reader; this card needs a 125KHz reader. Use our 13.56MHz key fob or Mifare cards with the MFRC522.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan I rewrite the ID?\u003c\/summary\u003e\u003cp\u003eNo, the UID is read-only - you read it and map it to a user in your code.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What frequency is this tag?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"125KHz, EM4100 protocol - a read-only card with a fixed UID.\"}}, {\"@type\": \"Question\", \"name\": \"Does it work with the MFRC522?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No. The MFRC522 is a 13.56MHz reader; this card needs a 125KHz reader. Use our 13.56MHz key fob or Mifare cards with the MFRC522.\"}}, {\"@type\": \"Question\", \"name\": \"Can I rewrite the ID?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No, the UID is read-only - you read it and map it to a user in your code.\"}}]}\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53478645006701,"sku":"CDN-3031","price":15.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/125khz-rfid-card-tag-em4100-proximity-6817257.webp?v=1785259747"},{"product_id":"rfid-125khz-card-tag-10-pack","title":"125KHz RFID Card Tag - Pack of 10 (EM4100)","description":"\u003ch1\u003e125KHz RFID Card Tag - Pack of 10 (EM4100)\u003c\/h1\u003e\n\u003cp\u003eA pack of ten 125KHz proximity RFID card tags (EM4100-compatible), each with its own read-only UID. The practical choice for classrooms, labs, and multi-user access or attendance projects where you need a card per person.\u003c\/p\u003e\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e125KHz readers such as the JT308, RDM6300 and EM-18\u003c\/li\u003e\n  \u003cli\u003eArduino, ESP32 and Raspberry Pi via a 125KHz reader module\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eBuild it with Compoden's AI\u003c\/h2\u003e\u003cp\u003ePairing a tag with the right reader and code trips up a lot of first builds. Describe your access-control or attendance project to Compoden's AI build assistant. It matches the tag to a compatible reader at the same frequency, checks every part against real stock, and hands you the wiring and the code.\u003c\/p\u003e\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eWe have spent 10 years supplying RFID, electronics, and robotics parts to makers, schools, and access-control projects across India. Every Compoden order includes our AI build companion to help you wire the reader, write the code, and get the tag reading on the first try.\u003c\/p\u003e\n\u003cdetails\u003e\u003csummary\u003eHow many cards are included?\u003c\/summary\u003e\u003cp\u003eTen 125KHz EM4100 cards, each with a unique read-only UID.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eAre these the same as the single card tag?\u003c\/summary\u003e\u003cp\u003eYes, the same 125KHz card in a pack of ten for multi-user builds.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDo they work with a 13.56MHz reader?\u003c\/summary\u003e\u003cp\u003eNo - these are 125KHz; the MFRC522 and other 13.56MHz readers will not read them.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"How many cards are included?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Ten 125KHz EM4100 cards, each with a unique read-only UID.\"}}, {\"@type\": \"Question\", \"name\": \"Are these the same as the single card tag?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes, the same 125KHz card in a pack of ten for multi-user builds.\"}}, {\"@type\": \"Question\", \"name\": \"Do they work with a 13.56MHz reader?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No - these are 125KHz; the MFRC522 and other 13.56MHz readers will not read them.\"}}]}\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53478645039469,"sku":"CDN-3032","price":114.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/125khz-rfid-card-tag-pack-of-10-em4100-8430715.webp?v=1785259747"},{"product_id":"rfid-13-56mhz-keychain-fob","title":"13.56MHz RFID Keychain Fob (MIFARE Classic)","description":"\u003ch1\u003e13.56MHz RFID Keychain Fob (MIFARE Classic)\u003c\/h1\u003e\n\u003cp\u003eA 13.56MHz MIFARE Classic key fob in a durable keychain form factor. It is the companion tag for the MFRC522 and other 13.56MHz readers, ideal for door locks and access control where a card is less convenient to carry.\u003c\/p\u003e\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eMFRC522 13.56MHz reader\/writer\u003c\/li\u003e\n  \u003cli\u003ePN532 and other 13.56MHz readers\u003c\/li\u003e\n  \u003cli\u003eWorks alongside 13.56MHz MIFARE cards\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eBuild it with Compoden's AI\u003c\/h2\u003e\u003cp\u003ePairing a tag with the right reader and code trips up a lot of first builds. Describe your access-control or attendance project to Compoden's AI build assistant. It matches the tag to a compatible reader at the same frequency, checks every part against real stock, and hands you the wiring and the code.\u003c\/p\u003e\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eWe have spent 10 years supplying RFID, electronics, and robotics parts to makers, schools, and access-control projects across India. Every Compoden order includes our AI build companion to help you wire the reader, write the code, and get the tag reading on the first try.\u003c\/p\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes it work with the MFRC522?\u003c\/summary\u003e\u003cp\u003eYes. It is a 13.56MHz MIFARE Classic tag, exactly what the MFRC522 reads.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs it the same as the RFID card, just a fob?\u003c\/summary\u003e\u003cp\u003eFunctionally yes - same 13.56MHz MIFARE technology in a keychain shape.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWill a 125KHz reader read it?\u003c\/summary\u003e\u003cp\u003eNo - this is 13.56MHz; use it with a 13.56MHz reader, not a 125KHz one.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Does it work with the MFRC522?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes. It is a 13.56MHz MIFARE Classic tag, exactly what the MFRC522 reads.\"}}, {\"@type\": \"Question\", \"name\": \"Is it the same as the RFID card, just a fob?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Functionally yes - same 13.56MHz MIFARE technology in a keychain shape.\"}}, {\"@type\": \"Question\", \"name\": \"Will a 125KHz reader read it?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No - this is 13.56MHz; use it with a 13.56MHz reader, not a 125KHz one.\"}}]}\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53478645072237,"sku":"CDN-3033","price":17.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/1356mhz-rfid-keychain-fob-mifare-classic-9763813.webp?v=1785259747"},{"product_id":"rfid-125khz-coin-tag","title":"125KHz RFID Coin Tag (ABS, with Hole)","description":"\u003ch1\u003e125KHz RFID Coin Tag (ABS, with Hole)\u003c\/h1\u003e\n\u003cp\u003eA 125KHz proximity RFID tag in a rugged ABS coin form factor with a mounting hole, so you can thread it onto a keyring or fix it to an asset. Read-only UID, for access control and identification with any 125KHz reader.\u003c\/p\u003e\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e125KHz readers such as the JT308, RDM6300 and EM-18\u003c\/li\u003e\n  \u003cli\u003eArduino, ESP32 and Raspberry Pi via a 125KHz reader module\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eBuild it with Compoden's AI\u003c\/h2\u003e\u003cp\u003ePairing a tag with the right reader and code trips up a lot of first builds. Describe your access-control or attendance project to Compoden's AI build assistant. It matches the tag to a compatible reader at the same frequency, checks every part against real stock, and hands you the wiring and the code.\u003c\/p\u003e\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eWe have spent 10 years supplying RFID, electronics, and robotics parts to makers, schools, and access-control projects across India. Every Compoden order includes our AI build companion to help you wire the reader, write the code, and get the tag reading on the first try.\u003c\/p\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat frequency is this?\u003c\/summary\u003e\u003cp\u003e125KHz, read-only UID - use it with a 125KHz reader.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes it work with the MFRC522?\u003c\/summary\u003e\u003cp\u003eNo, the MFRC522 is 13.56MHz; this coin is 125KHz.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat is the hole for?\u003c\/summary\u003e\u003cp\u003eTo thread it onto a keyring or fasten it to an asset you want to identify.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What frequency is this?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"125KHz, read-only UID - use it with a 125KHz reader.\"}}, {\"@type\": \"Question\", \"name\": \"Does it work with the MFRC522?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No, the MFRC522 is 13.56MHz; this coin is 125KHz.\"}}, {\"@type\": \"Question\", \"name\": \"What is the hole for?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"To thread it onto a keyring or fasten it to an asset you want to identify.\"}}]}\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53478645137773,"sku":"CDN-3034","price":58.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/125khz-rfid-coin-tag-abs-with-hole-3828374.png?v=1785259747"},{"product_id":"rfid-125khz-waterproof-tag","title":"125KHz Waterproof RFID Checkpoint Tag (40mm)","description":"\u003ch1\u003e125KHz Waterproof RFID Checkpoint Tag (40mm)\u003c\/h1\u003e\n\u003cp\u003eA 40mm waterproof 125KHz RFID checkpoint tag built for outdoor use - guard-patrol checkpoints, asset tracking, and any project where the tag is exposed to weather. Read-only UID, compatible with any 125KHz reader.\u003c\/p\u003e\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e125KHz readers such as the JT308, RDM6300 and EM-18\u003c\/li\u003e\n  \u003cli\u003eOutdoor patrol, attendance and asset-tracking projects\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eBuild it with Compoden's AI\u003c\/h2\u003e\u003cp\u003ePairing a tag with the right reader and code trips up a lot of first builds. Describe your access-control or attendance project to Compoden's AI build assistant. It matches the tag to a compatible reader at the same frequency, checks every part against real stock, and hands you the wiring and the code.\u003c\/p\u003e\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eWe have spent 10 years supplying RFID, electronics, and robotics parts to makers, schools, and access-control projects across India. Every Compoden order includes our AI build companion to help you wire the reader, write the code, and get the tag reading on the first try.\u003c\/p\u003e\n\u003cdetails\u003e\u003csummary\u003eIs it really waterproof?\u003c\/summary\u003e\u003cp\u003eIt uses a sealed 40mm housing suited to outdoor and damp environments.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat frequency?\u003c\/summary\u003e\u003cp\u003e125KHz, read-only UID - pair it with a 125KHz reader.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat is it used for?\u003c\/summary\u003e\u003cp\u003eGuard-patrol checkpoints, outdoor attendance, and tracking assets that live outside.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Is it really waterproof?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It uses a sealed 40mm housing suited to outdoor and damp environments.\"}}, {\"@type\": \"Question\", \"name\": \"What frequency?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"125KHz, read-only UID - pair it with a 125KHz reader.\"}}, {\"@type\": \"Question\", \"name\": \"What is it used for?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Guard-patrol checkpoints, outdoor attendance, and tracking assets that live outside.\"}}]}\u003c\/script\u003e","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53478645170541,"sku":"CDN-3035","price":39.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/125khz-waterproof-rfid-checkpoint-tag-40mm-9026765.png?v=1785259747"},{"product_id":"125khz-writable-rfid-t5557-t5567-t5577-rewritable-proximity-card-for-id-writer-copier-duplicate-thin-card","title":"125khz Writable RFID T5557 \/ T5567 \/ T5577 Rewritable Proximity Card for ID Writer Copier Duplicate (Thin Card)","description":"\u003ch1\u003e125kHz Writable RFID T5557 \/ T5567 \/ T5577 Rewritable Proximity Card for ID Writer Copier Duplicate (Thin Card)\u003c\/h1\u003e\n\u003cp\u003eThis 125kHz rewritable RFID proximity card uses the T5557, T5567, or T5577 chipset, allowing you to write and rewrite data for ID duplication and access control projects. It is a thin, passive card with no battery needed, designed for contactless data transmission. Ideal for makers, hobbyists, and engineers working with RFID writer copier systems.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eOperating Frequency: 125kHz\u003c\/li\u003e\n\u003cli\u003eChipset: T5557 \/ T5567 \/ T5577 (rewritable)\u003c\/li\u003e\n\u003cli\u003eOperating Distance: Up to 1 meter (depends on antenna geometry)\u003c\/li\u003e\n\u003cli\u003eData Transfer Speed: 106 kbit\/s\u003c\/li\u003e\n\u003cli\u003ePower Source: Passive (no battery required)\u003c\/li\u003e\n\u003cli\u003eForm Factor: Thin card\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eArduino (Uno, Mega, Nano)\u003c\/li\u003e\n\u003cli\u003eESP32\u003c\/li\u003e\n\u003cli\u003eESP8266\u003c\/li\u003e\n\u003cli\u003eRaspberry Pi\u003c\/li\u003e\n\u003cli\u003eSTM32\u003c\/li\u003e\n\u003cli\u003e125kHz RFID reader\/writer modules (e.g., RDM6300, RDM630)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhat you can build with it\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eCustom ID card duplication system for office or school access\u003c\/li\u003e\n\u003cli\u003eRewritable RFID tag for attendance tracking projects\u003c\/li\u003e\n\u003cli\u003ePrototype for contactless door lock with user-programmable cards\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eBuilt and Backed by Compoden\u003c\/h3\u003e\n\u003cp\u003eEvery card comes with access to our AI build companion, delivered via QR code, email, or WhatsApp, to help you wire and program it into a working project. With 10 years of experience supplying makers and institutions across India, we ensure reliable components for your builds. Pay your way: UPI or cards anywhere in India, plus COD if checkout offers it for your order.\u003c\/p\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWhat payment options are available for this RFID card?\u003c\/summary\u003e\n\u003cp\u003eWe accept UPI, credit\/debit cards, and Cash on Delivery (COD) if checkout offers it for your order.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow do I write data to this card?\u003c\/summary\u003e\n\u003cp\u003eYou need a 125kHz RFID writer module (like RDM6300) and an Arduino or ESP32. Connect the module, use a library like RFID or MFRC522, and send write commands to the T5557\/T5567\/T5577 chip.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow long does delivery take?\u003c\/summary\u003e\n\u003cp\u003eWe ship this RFID card across India including Delhi, Mumbai, Bangalore, Hyderabad, Chennai, and Pune. Standard delivery takes 2-7 days after dispatch, depending on your location.\u003c\/p\u003e\n\u003c\/details\u003e\n\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53492640022893,"sku":"CDN-2022","price":231.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/125khz-writable-rfid-t5557-t5567-t5577-rewritable-proximity-card-for-id-writer-copier-duplicate-thin-card-9022638.png?v=1785259569"},{"product_id":"rfid-card-inductive-module-mfrc-522-with-key-chain","title":"MFRC522 RFID Reader Kit with Card and Key-Chain Tag","description":"\u003ch1\u003eRFID Card Inductive Module MFRC-522 with Key Chain\u003c\/h1\u003e\n\n\u003cp\u003eThe MFRC-522 is a 13.56 MHz RFID module that reads and writes to passive RFID tags and key chains. It is designed for contactless identification and access control applications, commonly used by makers and students in India.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eOperating frequency: 13.56 MHz\u003c\/li\u003e\n\u003cli\u003eInterface: SPI (Serial Peripheral Interface)\u003c\/li\u003e\n\u003cli\u003eLogic level: 3.3V (not 5V tolerant; use a level shifter with 5V boards)\u003c\/li\u003e\n\u003cli\u003eRead range: Up to 5 cm\u003c\/li\u003e\n\u003cli\u003eSupported tag types: MIFARE Classic 1K, MIFARE Ultralight\u003c\/li\u003e\n\u003cli\u003eDimensions: 40 mm x 60 mm\u003c\/li\u003e\n\u003cli\u003eIncludes: One MFRC-522 module, one RFID card, one key chain tag\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible with\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eArduino (Uno, Nano, Mega)\u003c\/li\u003e\n\u003cli\u003eESP32\u003c\/li\u003e\n\u003cli\u003eESP8266\u003c\/li\u003e\n\u003cli\u003eRaspberry Pi (via SPI)\u003c\/li\u003e\n\u003cli\u003eSTM32\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhat you can build with it\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eRFID-based door lock system with Arduino\u003c\/li\u003e\n\u003cli\u003eAttendance logging system for classrooms or offices\u003c\/li\u003e\n\u003cli\u003eContactless payment terminal prototype\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eBuilt and Backed by Compoden\u003c\/h2\u003e\n\u003cp\u003eCompoden has supplied electronics to Indian makers, schools, and engineering institutions for over 10 years. Every purchase includes access to our AI build companion, delivered via QR code, email, or WhatsApp, which helps you wire and program this module into a working project. Pay your way: UPI or cards anywhere in India, plus COD if checkout offers it for your order.\u003c\/p\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow do I connect the MFRC-522 to an Arduino?\u003c\/summary\u003e\n\u003cp\u003eConnect the module's SPI pins (SDA, SCK, MOSI, MISO) to the corresponding Arduino SPI pins through a level shifter (Uno, Nano and Mega use 5V logic), and power it with 3.3V and GND. The IRQ pin is optional. Use the MFRC522 library by Miguel Balboa for programming.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWhat payment options are available for the RFID Card Inductive Module MFRC-522 with Key Chain?\u003c\/summary\u003e\n\u003cp\u003eYou can pay using UPI, credit\/debit cards, or Cash on Delivery (COD) if checkout offers it for your order. All payment methods are available across India.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow long does delivery take?\u003c\/summary\u003e\n\u003cp\u003eWe ship the RFID Card Inductive Module MFRC-522 with Key Chain across India including Delhi, Mumbai, Bangalore, Hyderabad, Chennai, and Pune. Delivery takes 2-7 days after dispatch, depending on your location.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cp\u003eBuy RFID Card Inductive Module MFRC-522 with Key Chain online in India with UPI and cards, plus COD if checkout offers it for your order.\u003c\/p\u003e\n\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53492640940397,"sku":"CDN-2280","price":260.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/rfid-card-inductive-module-mfrc-522-with-key-chain-7791058.jpg?v=1785259568"}],"url":"https:\/\/compoden.com\/collections\/rfid-nfc-modules.oembed","provider":"Compoden","version":"1.0","type":"link"}