BSM3 hydrogen alarm module

A 20 × 20 mm PCB module with a 3.3 V GPIO alarm output.

Module specifications

Detection
Alarm setpoint	500 ppm H₂, set by TIPS before shipment
Factory test	Alarm ≤30 s at 4000 ppm H₂
Calibration	Each module calibrated before shipment
Sampling rate	≥0.5 Hz

Output
Standard	Push-pull GPIO, 3.3 V: High when alarm is active, Low when inactive or cleared
Project options	UART or CAN — project development and validation required

Electrical & mechanical
Supply	5 V
Current	<100 µA (typical)
Size	20 × 20 mm
Supply format	PCB module, without enclosure

Environment
Temperature	-10 to 50 °C
Humidity	20–80% RH, non-condensing

Reliability
Damp heat test	85 °C / 85% RH, 1,000 h
Result	Alarm function normal, no recalibration required
Source	TIPS internal test

Standard integration uses the five pins on the right edge.

Right edge · top to bottom
1 · Top	+5 V supply
2	Heartbeat output (3.3 V GPIO, toggles about every 1 s)
3	Alarm output (3.3 V GPIO, active high)
4	Mode — factory use. Leave unconnected or connect to GND for normal operation. Do not drive high.
5 · Bottom	GND

Left-edge pads are for programming, debug and serial access, and are not used in standard integration.

Tell us about your application. Technical details and drawings available on request.