SensorPawA350.hpp File Reference

@license MIT License More...

#include "../../../SensorBuildOpt.h"
#include "platform/comm/I2CDeviceWithHal.hpp"

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Classes
class	SensorPawA350
	PAW-A350 Optical Finger Navigation Sensor Driver. More...
struct	SensorPawA350::MotionData
	Motion Delta Data. More...

Detailed Description

@license MIT License

Copyright (c) 2026 lewis he

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Author

Lewis He (lewis.nosp@m.he@o.nosp@m.utloo.nosp@m.k.co.nosp@m.m)

Date

2026-04-11

PAW-A350 Optical Finger Navigation (OFN) Sensor Driver

Overview

The PAW-A350 is an optical finger navigation sensor from PixArt Imaging. It provides motion detection and finger tracking capabilities through an I2C interface. The sensor measures surface motion by comparing successive images of the fingerprint and calculating the displacement.

Features

• I2C interface (slave address 0x33)
• Count per inch (CPI) resolution: 125, 250, 500, 750, 1000, 1250
• 8-bit two's complement motion delta output (-128 to +127)
• Multiple power management states: Run, Rest1, Rest2, Rest3
• Configurable LED drive current and shutter control
• Motion interrupt support

Register

Address	Register Name	Description
0x00	PRODUCT_ID	Unique chip identification (default: 0x88)
0x01	REVISION_ID	IC revision number
0x02	EVENT	Event status register (motion, reset, FPD)
0x03	Delta_X	X movement delta (8-bit signed)
0x04	Delta_Y	Y movement delta (8-bit signed)
0x11	Rest1_Period	Rest1 frame period
0x13	Run_Downshift	Run to Rest1 downshift time
0x15	Rest1_Downshift	Rest1 to Rest2 downshift time
0x16	Rest2_Period	Rest2 frame period
0x17	Rest2_Downshift	Rest2 to Rest3 downshift time
0x18	Rest3_Period	Rest3 frame period
0x1A	LED_CTRL	LED control and drive current
0x3A	SOFT_RESET	Software reset (write 0x5A)
0x3B	Shutter_Max_Hi	Shutter max open time (upper byte)
0x3C	Shutter_Max_Lo	Shutter max open time (lower byte)
0x62	CPI_SEL	Count per inch resolution setting
0x74	MOTION_CTRL	Motion interrupt threshold control
0x7A	FPD_FLAG	Finger presence detect flag

Management Features

The sensor supports 4 power states to reduce power consumption:

1. Run State - Full operation, highest power consumption
2. Rest1 State - Reduced frame rate after Run_Downshift time
3. Rest2 State - Further reduced frame rate after Rest1_Downshift time
4. Rest3 State - Lowest frame rate, minimal power

Downshift timing formulas:

• Run_Downshift: RD[7:0] x 8 x 8ms (default: 256ms)
• Rest1_Period: (R1R[7:0] + 1) x 10ms (default: 20ms)
• Rest1_Downshift: R1D[7:0] x 16 x Rest1_Period (default: 9.92s)
• Rest2_Period: (R2R[7:0] + 1) x 10ms (default: 100ms)
• Rest2_Downshift: R2D[7:0] x 128 x Rest2_Period (default: 10min)
• Rest3_Period: (R3R[7:0] + 1) x 10ms (default: 500ms)

Definition in file SensorPawA350.hpp.