Sensor modules
AXS-046 — GPS/GNSS carrier PMOD module
Catalog #46 in the AruviX sensor line, level L3 (UART, NMEA parsing, PPS timing).
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 decoupling | GRM188R71C104KA01DMurata |
C_0603_1608Metric |
C2 |
10uF 10V X5R | Acquisition-current bulk reservoir at the GPS socket | GRM21BR61A106KE19LMurata |
C_0805_2012Metric |
J1 |
PMOD PLUG 2x6 | PMOD peripheral plug (Digilent spec 1.2) | not selected generic |
PinHeader_2x06_P2.54mm_Horizontal |
J2 |
GPS BREAKOUT SOCKET | Socket for a 3.3 V UART GPS breakout with PPS | not selected generic |
PinSocket_1x05_P2.54mm_Vertical |
R1 |
100R | Series protection on the module-driven UART TX line | RC0603FR-07100RLYageo Datasheet ↗ |
R_0603_1608Metric |
R2 |
100R | Series protection on the module-driven PPS line | RC0603FR-07100RLYageo Datasheet ↗ |
R_0603_1608Metric |
Signals#
Net labels used in the schematic, which are also the names the HDL top level should use.
3V3 GND GPS_PPS GPS_TX PPS RXD TXD
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-046-gps
Catalog #46 in the AruviX sensor line (../README.md), level L3 (UART, NMEA parsing, PPS timing).
Status: schematic generated, ERC clean (0/0), netlist reviewed. PCB layout not started. Not released.
What it teaches#
A UART receiver in fabric, streaming NMEA sentence parsing (a nice character-FSM exercise), and using the 1 Hz PPS edge as a precision time reference — e.g. disciplining a fabric counter against it.
Design#
This is a carrier for a 3.3 V GPS breakout (ATGM336H-class) on a 1×5 socket: 3V3 / RX / TX / PPS / GND. Breakout pin orders vary — check against the J2 silkscreen before plugging in. A fully SMT carrier with the castellated ATGM336H footprint is deferred until that footprint is verified against the vendor drawing.
- 100 Ω series on the module-driven TX and PPS lines.
- 10 µF reservoir for acquisition current at the socket.
- TXD/RXD are named from the host FPGA's viewpoint; PPS rides in the PMOD Type 3 CTS position (pin 1).
| PMOD pin | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Net | PPS | TXD | RXD | NC | GND | 3V3 | NC | NC | NC | NC | GND | 3V3 |
Regenerate#
python3 generate_design.py
Remaining for release#
- [ ] PCB layout (20 × 40 mm outline — socket + antenna clearance), DRC, fab
- [ ]
hdl/: UART RX core, NMEA parser, PPS-disciplined counter, testbench, ECP5 demo - [ ] BOM export and availability check, design-review checklist