Sensor modules

AXS-047 — RC522 RFID carrier PMOD module

Catalog #47 in the AruviX sensor line, level L3 (SPI).

Level L3 ERC clean DRC clean Fab package 7 components

3D render of the AXS-047 PCB — Rendered from the PCB layout. No physical board has been manufactured.

Components#

Every placed component, with the reason it is on the board. Extracted directly from the schematic, so this cannot drift from the design.

Ref	Value	What it does on this board	Part number	Footprint
`C1`	100nF 16V X7R	Socket decoupling	`GRM188R71C104KA01D` Murata	`C_0603_1608Metric`
`C2`	10uF 10V X5R	RF transmit-burst bulk reservoir at the socket	`GRM21BR61A106KE19L` Murata	`C_0805_2012Metric`
`J1`	PMOD PLUG 2x6	PMOD peripheral plug (Digilent spec 1.2)	not selected generic	`PinHeader_2x06_P2.54mm_Horizontal`
`J2`	RC522 SOCKET	Socket for the common RC522 breakout: 1 SDA/SS, 2 SCK, 3 MOSI, 4 MISO, 5 IRQ, 6 GND, 7 RST, 8 3.3V	not selected generic	`PinSocket_1x08_P2.54mm_Vertical`
`R1`	100R	Series protection on the module-driven MISO line	`RC0603FR-07100RL` Yageo Datasheet ↗	`R_0603_1608Metric`
`R2`	100R	Series protection on the module-driven IRQ line	`RC0603FR-07100RL` Yageo Datasheet ↗	`R_0603_1608Metric`
`R3`	10k	RST_N pull-up: reader out of reset until the host drives it low	`RC0603FR-0710KL` Yageo Datasheet ↗	`R_0603_1608Metric`

Signals#

Net labels used in the schematic, which are also the names the HDL top level should use.

3V3 CS_N GND MISO MOSI RC522_IRQ RC522_MISO RFID_IRQ RST_N SCK

Production status#

Schematic ERC	0 violations
PCB layout	complete
DRC	0 violations
Fab package	exported (24 gerbers + drill + CPL + BOM)
Fabricated	no — design stage only

Source: boards/sensor-modules/axs-047-rfid

Catalog #47 in the AruviX sensor line (../README.md), level L3 (SPI).

Status: schematic generated, ERC clean (0/0), netlist reviewed. PCB layout not started. Not released.

What it teaches#

A real SPI register map. The MFRC522 is not a "clock out a frame" device: it has FIFOs, interrupt registers, a CRC coprocessor, and timeouts. On top of that sits the ISO14443A protocol lesson — REQA, anticollision, SELECT — to read MIFARE card UIDs. The IRQ line (PMOD pin 7) motivates interrupt-driven design over polling.

Design#

This is a carrier for the ubiquitous RC522 blue board (3.3 V only) on a 1×8 socket, J2, in the common blue-board order:

1 SDA(SS), 2 SCK, 3 MOSI, 4 MISO, 5 IRQ, 6 GND, 7 RST, 8 3.3V

Clone boards occasionally differ — verify your breakout's silkscreen against the J2 order before fitting. (The blue board straps the MFRC522 into SPI mode; the "SDA" pin is the SPI ~SS.)

100 Ω series on the module-driven MISO and IRQ lines.
RST_N pulled up to 3V3 with 10 k on-module (reader out of reset by default); host-driven from PMOD pin 8.
~CS, MOSI, SCK host-driven, wired directly.
100 nF + 10 µF at the socket (RF transmit bursts).
PMOD Type 2A (expanded SPI): IRQ on pin 7, reset on pin 8.

PMOD pin	1	2	3	4	5	6	7	8	9	10	11	12
Net	CS_N	MOSI	MISO	SCK	GND	3V3	RFID_IRQ	RST_N	NC	NC	GND	3V3

Regenerate#

python3 generate_design.py

Remaining for release#

[ ] PCB layout (keep carrier copper clear of the breakout's antenna area), DRC, fab
[ ] Verify RC522 breakout pin order against a purchased board
[ ] hdl/: SPI master, MFRC522 register layer, ISO14443A UID read FSM, testbench, ECP5 demo
[ ] BOM export and availability check, design-review checklist