Sensor modules

AXS-008 — BMP280 barometric-pressure PMOD module

Catalog #8 in the AruviX sensor line, level L3 (I2C). Uses the BMP280 instead of the catalog's original BMP390: the BMP280 is the stock-supported Bosch sibling in the same driver family, so the lesson (burst register reads, calibration-coefficient compensation math) carries over unchanged.

Level L3 ERC clean DRC clean Fab package 9 components

3D render of the AXS-008 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	U1 VDD decoupling	`GRM188R71C104KA01D` Murata	`C_0603_1608Metric`
`C2`	100nF 16V X7R	U1 VDDIO decoupling	`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`
`JP3`	ADDR 0x76/0x77	I2C address select: 1-2 SDO low 0x76 (default), 2-3 SDO high 0x77	—	`SolderJumper-3_P1.3mm_Bridged12_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`	BMP280	Absolute barometric pressure and temperature sensor, 300-1100 hPa, I2C/SPI	`BMP280` Bosch Sensortec Datasheet ↗	`Bosch_LGA-8_2x2.5mm_P0.65mm_ClockwisePinNumbering`

Signals#

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

3V3 ADDR 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-008-bmp280

Catalog #8 in the AruviX sensor line (../README.md), level L3 (I2C). Uses the BMP280 instead of the catalog's original BMP390: the BMP280 is the stock-supported Bosch sibling in the same driver family, so the lesson (burst register reads, calibration-coefficient compensation math) carries over unchanged.

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

What it teaches#

I2C burst reads of multi-byte registers, reading the factory calibration block once at init, and the BMP280's fixed-point compensation formulas — a substantial arithmetic exercise (32/64-bit intermediates) on top of the I2C master FSM.

Design#

Bosch BMP280, LGA-8. VDD and VDDIO both on 3V3, 100 nF each.
CSB tied to 3V3: the part is latched into I2C mode from power-on (a floating CSB can drop it into SPI mode on a bus glitch).
SDO is the I2C address pin: JP3 1-2 (default) = GND = 0x76, 2-3 = 3V3 = 0x77. Never float SDO in I2C mode.
4.7 kΩ bus pull-ups through JP1 (SDA) / JP2 (SCL), fitted by default; cut when another module on the chain provides the pull-ups.
No interrupt output on the BMP280 — PMOD pins 1/2/7/8 are NC.

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

reports/erc.rpt is the last kicad-cli ERC run.

Remaining for release#

[ ] PCB layout, DRC, fab outputs
[ ] hdl/: I2C master core, BMP280 controller + compensation math, testbench, ECP5 demo
[ ] BOM export and availability check, design-review checklist