Sensor modules

AXS-020 — TLV493D 3D hall-effect sensor PMOD module

Catalog #20 in the AruviX sensor line, level L3 (I2C). Uses the TLV493D-A1B6 instead of the catalog's original AS5600 (no stock KiCad assets): for the rotary-position lesson a diametral magnet spinning over a 3D hall sensor gives the shaft angle via atan2(By, Bx) computed in fabric, and adds a 3D-field-measurement and CORDIC exercise on top.

Level L3 ERC clean DRC clean Fab package 7 components

3D render of the AXS-020 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	VDD decoupling close to U1	`GRM188R71C104KA01D` Murata	`C_0603_1608Metric`
`J1`	PMOD PLUG 2x6	PMOD peripheral plug (Digilent spec 1.2)	not selected generic	`PinHeader_2x06_P2.54mm_Horizontal`
`JP1`	SDA PULL-UP	Cut to remove the SDA pull-up when chaining modules	—	`SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm`
`JP2`	SCL PULL-UP	Cut to remove the SCL pull-up when chaining modules	—	`SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm`
`R1`	4.7k	I2C SDA pull-up	`RC0603FR-074K7L` Yageo Datasheet ↗	`R_0603_1608Metric`
`R2`	4.7k	I2C SCL pull-up	`RC0603FR-074K7L` Yageo Datasheet ↗	`R_0603_1608Metric`
`U1`	TLV493D	Low-power 3D magnetic (hall) sensor, +/-130 mT, I2C, SOT-23-6	`TLV493D-A1B6 HTSA1` Infineon Datasheet ↗	`SOT-23-6`

Signals#

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

3V3 GND SCL SCL_PU SDA SDA_PU

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-020-tlv493d

Catalog #20 in the AruviX sensor line (../README.md), level L3 (I2C). Uses the TLV493D-A1B6 instead of the catalog's original AS5600 (no stock KiCad assets): for the rotary-position lesson a diametral magnet spinning over a 3D hall sensor gives the shaft angle via atan2(By, Bx) computed in fabric, and adds a 3D-field-measurement and CORDIC exercise on top.

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

What it teaches#

I2C register access to a 3-axis hall sensor, then rotary position: mount a diametral magnet on a shaft above the SOT-23 package and compute angle = atan2(By, Bx) (CORDIC or small-LUT lesson) in fabric.

Design#

TLV493D-A1B6 HTSA1, SOT-23-6, Infineon. 3V3 with 100 nF decoupling.
I2C address 0x5E. The A1B6 variant latches its address bit from the SDA level at power-up — keep the bus idle (SDA high through the pull-up) while VDD ramps; the on-module pull-up guarantees this when nothing drives SDA low during power-on.
No dedicated INT pin: when interrupt mode is enabled the sensor pulses the SCL line during bus idle. Leave interrupt mode off unless the host FSM tolerates it; no PMOD interrupt pin is wired.
4.7 kΩ bus pull-ups behind JP1 (SDA) / JP2 (SCL), bridged by default.
All sensor lines are the open-drain bus itself, so there is no separate sensor-driven line needing a 100 Ω series resistor.

PMOD pin	1	2	3	4	5	6	7	8	9	10	11	12
Net	NC	NC	SCL	SDA	GND	3V3	NC	NC	SCL	SDA	GND	3V3

Regenerate#

python3 generate_design.py

Remaining for release#

[ ] PCB layout (20 × 25 mm outline, magnet-over-sensor mounting target marked on silk), DRC, fab outputs
[ ] hdl/: I2C master, TLV493D controller, atan2/CORDIC angle demo
[ ] BOM export and availability check, design-review checklist