Comms modules

AXC-005 — nRF24L01+ socket carrier PMOD module

Catalog #5 in the AruviX comms line, level L3 (SPI + CE/IRQ). Socket carrier for the ubiquitous nRF24L01+ breakout — generic 2×4 pin socket, no custom footprint. Cheap two-way robot remote: pairs with the joystick module (axo-013) and the actuator line.

Level L3 ERC clean DRC clean Fab package 9 components

3D render of the AXC-005 PCB — Rendered from the PCB layout. No physical board has been manufactured.

Circuit review & bench-test guide →

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 HF decoupling	`GRM188R71C104KA01D` Murata	`C_0603_1608Metric`
`C2`	10uF 10V X5R	Socket bulk: nRF24 TX ramp brownout is the classic failure	`GRM21BR61A106KE19L` Murata	`C_0805_2012Metric`
`C3`	10uF 10V X5R	Socket bulk (second reservoir)	`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`	nRF24 SOCKET (2x4)	Socket for an nRF24L01+ breakout: 1 GND, 2 VCC, 3 CE, 4 CSN, 5 SCK, 6 MOSI, 7 MISO, 8 IRQ	not selected generic	`PinSocket_2x04_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	~IRQ pull-up (active-low interrupt, pulled up on-module per line rule)	`RC0603FR-0710KL` Yageo Datasheet ↗	`R_0603_1608Metric`
`R4`	10k	CE pull-DOWN: radio stays in standby until the host drives CE high	`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 CE CS_N GND IRQ_N MISO MOSI NRF_IRQ NRF_MISO 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/comms-modules/axc-005-nrf24

Catalog #5 in the AruviX comms line (../README.md), level L3 (SPI + CE/IRQ). Socket carrier for the ubiquitous nRF24L01+ breakout — generic 2×4 pin socket, no custom footprint. Cheap two-way robot remote: pairs with the joystick module (axo-013) and the actuator line.

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

What it teaches#

Enhanced ShockBurst packet radio: SPI command set, auto-ack/retransmit, pipe addressing, and the CE/~IRQ dance (CE pulse >10 µs fires a packet; ~IRQ signals RX/TX/MAX_RT events on a PMOD pin per the platform rule).

Design#

J2 = standard nRF24 2×4 socket pinout: 1 GND, 2 VCC, 3 CE, 4 CSN, 5 SCK, 6 MOSI, 7 MISO, 8 IRQ. Orientation warning on the schematic and (at layout) silkscreen: a reversed breakout swaps VCC onto GND — match the breakout's own key/silkscreen before power.
PMOD Type 2A: 1 ~CS(CSN), 2 MOSI, 3 MISO via 100 Ω, 4 SCK, 7 ~IRQ via 100 Ω with 10 k pull-up (active low), 8 CE with 10 k pull-down so the radio stays in standby until the host drives it.
Bulk at the socket: 2 × 10 µF + 100 nF — brownout during the TX power-amp ramp is the classic nRF24 field failure on breakouts fed from thin rails.
RF keep-out: the socket end of the outline stays clear so the breakout's PCB antenna hangs off-board (line rule).

PMOD pin	1	2	3	4	5	6	7	8	9	10	11	12
Net	~CS	MOSI	MISO	SCK	GND	3V3	~IRQ	CE	NC	NC	GND	3V3

Regenerate#

python3 generate_design.py

Remaining for release#

[ ] PCB layout (socket at the far edge, antenna overhang, bulk caps at the socket pins), DRC, fab outputs
[ ] hdl/: nrf24_ctrl core, testbench, two-board link demo
[ ] BOM export and availability check, design-review checklist