I/O modules

AXO-013 — analog joystick carrier PMOD module

Catalog #13 in the AruviX output line, level L3. Socketed carrier for the common 5-pin XY thumbstick breakout (KY-023 class): the SKRH/COM-09032-class stick itself has no stock KiCad footprint (documented deferral), so the breakout plugs in.

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.

Signals#

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

3V3 ADC_DOUT CS_N GND JOY_SW JOY_X JOY_Y MISO MOSI SCK SW_RAW VRX_W VRY_W

Production status#

Source: boards/io-modules/axo-013-joystick

Catalog #13 in the AruviX output line (../README.md), level L3. Socketed carrier for the common 5-pin XY thumbstick breakout (KY-023 class): the SKRH/COM-09032-class stick itself has no stock KiCad footprint (documented deferral in ../README.md), so the breakout plugs in.

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

What it teaches#

Reading two analog axes plus a button over one PMOD: SPI ADC transactions, dead-zone/centering math in fabric, then Pong with the VGA module (axo-007) or robot teleop with the actuator line.

Design#

• ADC: Analog_ADC:MCP3202 — verified in stock, so the single dual-channel option is used and the catalog's 2× ADS7042 fallback is not needed. MCP3202-BI/SN (SOIC-8): dual-channel 12-bit SAR, 100 ksps, has DIN (MOSI) ✓. VREF = VDD = 3V3, matching the stick's rail-to-rail wipers. CH0 = X, CH1 = Y.
• J2 = 1×05 pin socket, typical order 1 VCC 2 GND 3 VRx 4 VRy 5 SW. ORDER-CHECK WARNING (on the schematic too): clones occasionally swap VRx/VRy or VCC/GND — verify your breakout's silkscreen before plugging in.
• RC per axis: 1 k + 10 nF (fc = 1/(2π·1k·10nF) ≈ 16 kHz): wiper-scratch low-pass and SAR charge reservoir at a source impedance the MCP3202 tolerates.
• SW (stick click, closes to GND): 10 k pull-up, then — as a module-driven line — 100 Ω series to PMOD pin 8.
• 10 k ~CS idle pull-up, 100 Ω on the ADC-driven DOUT→MISO line, 100 nF + 1 µF decoupling.

PMOD pin map (Type 2A SPI)#

Regenerate#

python3 generate_design.py

Remaining for release#

• [ ] PCB layout (breakout socket clear of the PMOD clip zone), DRC, fab outputs
• [ ] hdl/: SPI master + MCP3202 read core, dead-zone demo
• [ ] BOM export and availability check, design-review checklist