---
tags:
  - project
  - eg
active: false
created: 2024-02-06
---
## Goal

Reverse engineer MFRC522 RFID reader, create circuit design, add a ribbon cable connector, have RST pin be pulled low.

## To Do

- [x] Test MFRC522 in Rust crate ➕ 2024-09-29 ✅ 2025-05-02
- [x] Test the small picofarad capacitors to see what the values are ➕ 2024-10-28 ✅ 2025-03-02
- [x] Check that MFRC522 chips can be ordered on ➕ 2024-09-29 ✅ 2024-10-28
- [x] Decide on asymmetry of TX1/TX2 ➕ 2024-10-03 ✅ 2024-10-28
- [x] See which side of TX the RX/VMID connects to on the actual board ➕ 2024-10-03 ✅ 2024-10-08
- [x] Add ribbon cable connector ➕ 2024-06-20 ✅ 2024-10-03
- [x] Give all capacitors and resistors their values in circuit ➕ 2024-09-29 ✅ 2024-10-03
- [x] Connect crystal ➕ 2024-09-29 ✅ 2024-10-03
- [x] Connect LED ➕ 2024-09-29 ✅ 2024-10-03
- [x] Connect antenna ➕ 2024-09-29 ✅ 2024-10-03
- [x] Ensure pull up resistor to disable board ➕ 2024-09-29 ✅ 2024-10-03
- [x] Pull capacitors off of a working board to figure out what values they are ➕ 2024-06-25 ✅ 2024-09-29

## Notes

MF522-AN chip is based on the original Philips MFRC522 chip.  Every RFID chip has a unique ID.  Additionally you can store encrypted data on many RFID’s as well.

- https://arduino.stackexchange.com/questions/54119/mfrc522-firmware-unknown - getting version 0xB2 for clone boards
- Holding the RST pin low disables the board.  Board is reset by a positive edge and enabled when held high.
- [Instructables article on how to interface RPi to RC522](https://www.instructables.com/How-to-Interface-RFID-RC522-With-Raspberry-Pi/)
- [Donskytech article about using RPi with MFRC522 reader](https://www.donskytech.com/raspberry-pi-mfrc522-rfid-reader-spi/)
- [Tutorial that shows how to voltage regulate the 5V signals to 3.3V](https://arduinogetstarted.com/tutorials/arduino-rfid-nfc) and how to read on an Arduino. *Voltage regulation is not required - see note below*
- [Article about RC522 RFID modules](https://components101.com/wireless/rc522-rfid-module).  Explains that the communication pins of the board are 5V tolerant so no need to voltage regulate as other articles describe
- [Enabling SPI interface on Raspberry Pi](https://learn.sparkfun.com/tutorials/raspberry-pi-spi-and-i2c-tutorial/all)
- [Another interesting RC522 / Arduino tutorial](https://www.instructables.com/How-to-Use-the-RFID-RC522-Module-With-Arduino/)
- [How to use an RFID RC522 with a Raspberry Pi](http://wiki.sunfounder.cc/index.php?title=How_to_Use_an_RFID_RC522_on_Raspberry_Pi)
- [And another that talks about tag memory and how it is organized](https://peppe8o.com/rfid-and-raspberry-pi-rc522-wiring-and-code-with-python/)
- This chap on StackExchange explains [how to attach multiple RC522 readers to one RPi by cycling the RST pins and multiplexing the SPI](https://raspberrypi.stackexchange.com/questions/31773/raspberry-pi-multiple-nfc-readers/137491#137491).
- [Full MFRC522 Specification](https://www.nxp.com/docs/en/data-sheet/MFRC522.pdf)
- [All the different types of RFID tags and the different standards for each country](https://blogs.bu.edu/llisa/everything-you-need-to-know-about-rfid-tags/)
- [Rust MFRC522 driver](https://gitlab.com/jspngh/rfid-rs) for RFID chip reading
- [SPI - Serial Peripheral Interface pinout for Raspberry Pi](https://pinout.xyz/pinout/spi)
- [DIY Smart Lock](https://www.makeuseof.com/tag/diy-smart-lock-arduino-rfid/)
- [Read two RFID’s from same SPID using OR gate](https://forum.arduino.cc/t/2-mfrc522-in-one-arduino-solved/416925/3)
- [MFRC522 Circuit Diagram](https://easyeda.com/editor#id=!b4aaa5775d8340e8a0fc626cdb0c1cbe)
- https://easyeda.com/editor#id=!488e1b7a8f9544599a7f8e41d1d6ccb9
- [Optimizing Read Range in RFID Systems](https://ww1.microchip.com/downloads/en/market_communication/optedn_ps.pdf)
- http://miniradiosolutions.com/wp-content/uploads/2015/09/NFC-Reader-Design-II-Antenna-design-considerations-Public.pdf
- https://5.imimg.com/data5/SELLER/Doc/2022/1/NB/OG/UX/1833510/rc522-reader-writer-module.pdf

![Image.png](Resources/Electronics/RFID%20and%20NFC.assets/Image.png)

The RST pin of the RC522 RFID module is level triggered.  Low powers down the board, high powers up and causes a board reset.

![Image.png](Resources/Electronics/RFID%20and%20NFC.assets/Image%20(2).png)


![[RFID-Module-RC522-Kits-13-56-Mhz-6cm-With-Tags-SPI-Write-Read-for-Arduino-back.png]]

![[RFID-Module-RC522-Kits-13-56-Mhz-6cm-With-Tags-SPI-Write-Read-for-Arduino.jpg_.png]]

![[PICA0008.jpg]]

![[MFRC522-Back-Screen.jpeg]]

![[MFRC522-Front-Screen.jpeg]]

![[MFRC522-Back-Copper.jpeg]]

![[MFRC522-Front-Copper.jpeg]]
## References

- [RFID RC522 Schematic Resources](https://easyeda.com/modules/RFID-RC522-Schematic_488e1b7a8f9544599a7f8e41d1d6ccb9)
- https://easyeda.com/editor#id=!488e1b7a8f9544599a7f8e41d1d6ccb9
- https://easyeda.com/editor#id=!b4aaa5775d8340e8a0fc626cdb0c1cbe
- [How to Set Up a Raspberry Pi RFID RC522 Chip - Pi My Life Up](https://pimylifeup.com/raspberry-pi-rfid-rc522)
- [MFRC522 footprint and symbol by NXP USA Inc.](https://www.snapeda.com/parts/MFRC522/NXP%20USA/view-part/?ref=search&t=MFRC522)
- [mfrc522 - Rust](https://docs.rs/mfrc522/latest/mfrc522)
- [Resistor Sizes and Packages | Resistor Standards and Codes | Resistor Guide](https://eepower.com/resistor-guide/resistor-standards-and-codes/resistor-sizes-and-packages)
- [Learn by Example—Using an Impedance Smith Chart - Technical Articles](https://www.allaboutcircuits.com/technical-articles/learn-to-use-the-impedance-smith-chart-through-examples)
- [Review of R, X, and Z (Resistance, Reactance and Impedance) | Reactance and Impedance—R, L, And C | Electronics Textbook](https://www.allaboutcircuits.com/textbook/alternating-current/chpt-5/review-of-r-x-and-z)
- [Standard Inductor Values - RF Cafe](https://www.rfcafe.com/references/electrical/inductor-values.htm)
- [What is an SMD capacitor? Common capacitor values - SM Tech](https://somanytech.com/smd-capacitor-surface-mount-capacitor)
- [How to Calculate the Frequency of the Upper Sideband?](https://www.gauthmath.com/knowledge/How-to-calculate-the-frequency-of-the-upper-sideband--7389682134987374604)

![[RFID-Module-Circuit-Fixed.png]]

![[MFRC522.png]]


![[Design of Adaptive RFID Reader based on DDS and RC522 1.pdf]]

![[MFRC522 Antenna Design.pdf]]

