sensation 0.2.1

This is a library for communicating with IoT and home automation sensors and low-level devices.

Sensation

This is a Python library for communicating with IoT and home automation sensors and low-level devices.

Sensors

SEN0395

The SEN0395 is a millimeter-wave radar motion sensor capable of detecting human presence up to 9 meters away.

Code	SEN0395
Brand	DFRobot
Type	Millimeter-wave radar motion sensor
Name	mmWave Radar - 24GHz Human Presence Detection Sensor (9 Meters)
Alternative Names	LeapMMW HS2xx3A series
Python Package	sensation.sen0395
Product URL	DFRobot mmWave Radar

For more information about the product, refer to the SEN0395 documentation.

Commands not implemented yet

• resetCfg
• setInhibit/getInhibit
• setUart/getUart
• setGpioMode/getGpioMode
• setEcho/getEcho (disabling echo would likely break the current implementation)
• setUartOutput/getUartOutput
• getSWV/getHWV

Common Usage Examples

Sensor Instance (common code for the following examples)

from serial import Serial
from sensation.sen0395 import *

sensor = Sensor("sensor_name",  Serial('/dev/ttyAMA0', 115200, timeout=1))

sensor.status()  # Not needed, just checking that the sensor works well
# SensorStatus(sensor_id=SensorId(sensor_type=<SensorType.SEN0395: 'sen0395'>, sensor_name='sensor_name'), port='/dev/ttyAMA0', timeout=1, is_reading=False, is_scanning=False)

# >> DO YOUR OWN THINGS HERE <<

sensor.close()  # This closes also the `Serial` instance

Sensor Instance Async

import serialio
from sensation.sen0395 import *

async def example():
    serial_con = serialio.serial_for_url("serial:///dev/ttyAMA1", 115200)
    sensor = SensorAsync("my_sensor", serial_con)
    await serial_con.open()
    
    await sensor.status()  # Not needed, just checking that the sensor works well
    
    # >> DO YOUR OWN THINGS HERE <<
    
    await sensor.close()  # This closes also the serial connection instance

Presence Reading

sensor.read_presence()  # Returns `None` if sensor is not scanning

sensor.start_scanning()
# CommandResponse(outputs=[sensorStart, Done])

sensor.read_presence()  # Returns `False` on no presence
# False

sensor.read_presence()  # Returns `True` on presence
# True

Presence Reading Async

await sensor.start_scanning()
await sensor.read_presence()

Presence Observer

handler = PresenceHandler()
handler.observers.append(lambda presence: print(f"[presence_change] presence=[{presence}]"))
sensor.handlers.append(handler)

# sensor.clear_buffer() # You may want to clear the buffer first, if the connection has been opened for a while
sensor.start_reading()  # This starts a new thread, alternatively you can run the blocking `read()` method by yourself
# [presence_change] presence=[False]
# [presence_change] presence=[True]
sensor.stop_reading()

Presence Observer Async

handler = PresenceHandlerAsync()
# Supports both sync...
handler.observers.append(lambda presence: print(f"[presence_change] presence=[{presence}]"))
# ...and async observers
async def async_observer(presence):
    print(f"[presence_change] presence=[{presence}]")
handler.observers.append(async_observer)

sensor.handlers.append(handler)

# await sensor.clear_buffer() # You may want to clear the buffer first, if the connection has been opened for a while
sensor.start_reading()  # This starts a new async task
await sensor.stop_reading()  # Wait for the reading task to complete

Managed Sensor Configuration

sensor.configure_latency(10, 60)
# ConfigChainResponse(pause_cmd=None, cfg_cmd=CommandResponse(outputs=[outputLatency -1 10 60, Done]), save_cmd=CommandResponse(outputs=[saveCfg 0x45670123 0xCDEF89AB 0x956 128C6 0xDF54AC89, save cfg complete, Done]), resume_cmd=None)

Managed Sensor Configuration Async

await sensor_async.configure_latency(10, 60)

Manual Sensor Configuration

Note: All below methods are async in the async sensor

sensor.stop_scanning()
#CommandResponse(outputs=[sensorStop, Done])

sensor.set_latency(15, 35)
# CommandResponse(outputs=[outputLatency -1 15 35, Done])

sensor.save_configuration()
# CommandResponse(outputs=[saveCfg 0x45670123 0xCDEF89AB 0x956128C6 0xDF54AC89, save cfg complete, Done])

sensor.start_scanning()
# CommandResponse(outputs=[sensorStart, Done])
#SensorStatus(sensor_id=SensorId(sensor_type=<SensorType.SEN0395: 'sen0395'>, sensor_name='sensor_name'), port='/dev/ttyAMA0', timeout=1, is_reading=False, is_scanning=True)

SEN0311

The SEN0311 is an ultrasonic distance measurement sensor that can be used to detect presence by measuring the distance to objects.

Code	SEN0311
Brand	DFRobot
Type	Ultrasonic distance measurement sensor
Name	A02YYUW Waterproof Ultrasonic Sensor
Python Package	sensation.sen0311
Product URL	DFRobot Ultrasonic Sensor

Common Usage Examples

Sensor Instance (Async)

import serialio
from sensation.sen0311 import SensorAsync

async def example():
    serial_con = serialio.serial_for_url("serial:///dev/ttyAMA1", 9600)
    sensor = SensorAsync("my_sensor", serial_con, distance_min=0, distance_max=4500)
    await serial_con.open()
    
    status = await sensor.status()  # Check if the sensor is working properly
    
    # >> DO YOUR OWN THINGS HERE <<
    
    await sensor.close()  # This closes the serial connection instance

Distance Measurement

# Perform a single measurement
measurement = await sensor.measure()
print(f"Distance: {measurement.distance}mm, State: {measurement.state}")

# Start continuous measurement with 0.5 second interval
sensor.start_reading(sleep_interval=0.5)

# Stop continuous measurement
await sensor.stop_reading()

Presence Detection with Thresholds

# Create a presence handler with custom thresholds
handler = PresenceHandlerAsync(
    threshold_presence=1000,   # Consider present when distance < 1000mm
    threshold_absence=1500,    # Consider absent when distance > 1500mm
    hysteresis_count=3,        # Require 3 consecutive readings to change state
    delay_presence=0.0,        # No delay when detecting presence
    delay_absence=5.0,         # 5 second delay before confirming absence
)

# Add observer to handle presence changes (supports both sync and async callbacks)
handler.observers.append(lambda presence: print(f"Presence changed: {presence}"))

# Add async observer
async def async_observer(presence):
    print(f"Async presence notification: {presence}")
    # Do async operations here
    
handler.observers.append(async_observer)

# Add the handler to the sensor
sensor.handlers.append(handler)

# Start reading with 0.2 second interval
sensor.start_reading(sleep_interval=0.2)

The SEN0311 sensor can detect distances from a few centimeters to about 4.5 meters, making it suitable for various presence detection applications where ultrasonic technology is appropriate, such as detecting people or objects in enclosed spaces.