Presence mmWave and light sensors

I wanted a presence sensor (not only distance, but also position and speed) to automate my lighting with Home Assistant.

This sensor also needed to detect ambient light levels so that it wouldn't turn on the lights in broad daylight.

I found this model, but my ESP32 was too thick.

So I decided to make my own version, which is just as compact (52mm x 40mm x 12mm).

I recommend printing in PETG, even though I added ventilation holes to the case.

Materials used

• ESP32-C3 SuperMini (~€2.30 on Aliexpress:)
• LD2450 (~€1.90 on Aliexpress)
• BH1750 (~€0.11 on Aliexpresshttps://fr.aliexpress.com/item/1005006794832418.html)
• 4x M3x4mm
• 1x M3x10mm

That's less than €5, compared to commercial probes that can cost up to €50 for a similar model.

How to assemble

Wiring

EspHome configuration

esphome:

name: presence

friendly_name: Présence

 

esp32:

board: esp32-c3-devkitm-1

framework:

type: esp-idf

 

logger:

 

# Enable Home Assistant API

api:

encryption:

key: "/Fv1TmNIZRKUZMQ9ruQ="

 

ota:

- platform: esphome

password: "gfhfghjhg"

 

wifi:

ssid: !secret wifi_ssid

password: !secret wifi_password

output_power : 8.5db

 

ap:

ssid: "Presence Fallback Hotspot"

password: "KqGT9GQ"

 

captive_portal:

 

uart:

id: uart_bus

tx_pin: GPIO21

rx_pin: GPIO20

baud_rate: 256000

parity: NONE

stop_bits: 1

 

i2c:

id: i2c_bus

sda: GPIO01

scl: GPIO00

scan: true

 

ld2450:

id: ld2450_radar

uart_id: uart_bus

 

binary_sensor:

- platform: ld2450

ld2450_id: ld2450_radar

has_target:

name: Presence

has_moving_target:

name: Moving Target

has_still_target:

name: Still Target

 

switch:

- platform: ld2450

ld2450_id: ld2450_radar

bluetooth:

name: "Bluetooth"

multi_target:

name: "Multi Target Tracking"

 

select:

- platform: ld2450

ld2450_id: ld2450_radar

baud_rate:

name: "Baud rate"

zone_type:

name: "Zone Type"

 

button:

- platform: ld2450

ld2450_id: ld2450_radar

factory_reset:

name: "LD2450 Factory Reset"

entity_category: "config"

restart:

name: "LD2450 Restart"

entity_category: "config"

 

text_sensor:

- platform: ld2450

ld2450_id: ld2450_radar

version:

name: "LD2450 Firmware"

mac_address:

name: "LD2450 BT MAC"

target_1:

direction:

name: "Target-1 Direction"

target_2:

direction:

name: "Target-2 Direction"

target_3:

direction:

name: "Target-3 Direction"

 

number:

- platform: ld2450

ld2450_id: ld2450_radar

presence_timeout:

name: "Timeout"

zone_1:

x1:

name: Zone-1 X1

y1:

name: Zone-1 Y1

x2:

name: Zone-1 X2

y2:

name: Zone-1 Y2

zone_2:

x1:

name: Zone-2 X1

y1:

name: Zone-2 Y1

x2:

name: Zone-2 X2

y2:

name: Zone-2 Y2

zone_3:

x1:

name: Zone-3 X1

y1:

name: Zone-3 Y1

x2:

name: Zone-3 X2

y2:

name: Zone-3 Y2

 

sensor:

- platform: bh1750

name: "BH1750 Illuminance"

address: 0x23

update_interval: 10s

- platform: ld2450

ld2450_id: ld2450_radar

target_count:

name: Presence Target Count

- platform: ld2450

ld2450_id: ld2450_radar

still_target_count:

name: Still Target Count

- platform: ld2450

ld2450_id: ld2450_radar

moving_target_count:

name: Moving Target Count

- platform: ld2450

ld2450_id: ld2450_radar

target_1:

x:

name: Target-1 X

y:

name: Target-1 Y

speed:

name: Target-1 Speed

angle:

name: Target-1 Angle

distance:

name: Target-1 Distance

resolution:

name: Target-1 Resolution

target_2:

x:

name: Target-2 X

y:

name: Target-2 Y

speed:

name: Target-2 Speed

angle:

name: Target-2 Angle

distance:

name: Target-2 Distance

resolution:

name: Target-2 Resolution

target_3:

x:

name: Target-3 X

y:

name: Target-3 Y

speed:

name: Target-3 Speed

angle:

name: Target-3 Angle

distance:

name: Target-3 Distance

resolution:

name: Target-3 Resolution

zone_1:

target_count:

name: Zone-1 All Target Count

still_target_count:

name: Zone-1 Still Target Count

moving_target_count:

name: Zone-1 Moving Target Count

zone_2:

target_count:

name: Zone-2 All Target Count

still_target_count:

name: Zone-2 Still Target Count

moving_target_count:

name: Zone-2 Moving Target Count

zone_3:

target_count:

name: Zone-3 All Target Count

still_target_count:

name: Zone-3 Still Target Count

moving_target_count:

name: Zone-3 Moving Target Count

Home Assistant Card

type: custom:plotly-graph
title: Zone 1
refresh_interval: 1
hours_to_show: current_day
layout:
 height: 230
 margin:
   l: 50
   r: 20
   t: 20
   b: 40
 showlegend: true
 xaxis:
   dtick: 1000
   gridcolor: RGBA(200,200,200,0.15)
   zerolinecolor: RGBA(200,200,200,0.15)
   type: number
   fixedrange: true
   autorange: reversed
   range:
     - -4000
     - 4000
 yaxis:
   dtick: 1000
   gridcolor: RGBA(200,200,200,0.15)
   zerolinecolor: RGBA(200,200,200,0.15)
   scaleanchor: x
   scaleratio: 1
   fixedrange: true
   range:
     - 7500
     - 0
entities:
 - entity: ""
   name: Target 1
   marker:
     size: 12
   line:
     shape: spline
     width: 5
   x:
     - $ex hass.states["sensor.presence_bureau_target_1_x"].state
   "y":
     - $ex hass.states["sensor.presence_bureau_target_1_y"].state
 - entity: ""
   name: Target 2
   marker:
     size: 12
   line:
     shape: spline
     width: 5
   x:
     - $ex hass.states["sensor.presence_bureau_target_2_x"].state
   "y":
     - $ex hass.states["sensor.presence_bureau_target_2_y"].state
 - entity: ""
   name: Personne 03
   marker:
     size: 12
   line:
     shape: spline
     width: 5
   x:
     - $ex hass.states["sensor.presence_bureau_target_3_x"].state
   "y":
     - $ex hass.states["sensor.presence_bureau_target_3_y"].state
 - entity: ""
   name: Zone 2
   mode: lines
   fill: toself
   fillcolor: RGBA(20,200,0,0.06)
   line:
     color: RGBA(20,200,0,0.2)
     shape: line
     width: 2
   x:
     - $ex hass.states["number.presence_bureau_zone_1_x1"].state
     - $ex hass.states["number.presence_bureau_zone_1_x1"].state
     - $ex hass.states["number.presence_bureau_zone_1_x2"].state
     - $ex hass.states["number.presence_bureau_zone_1_x2"].state
     - $ex hass.states["number.presence_bureau_zone_1_x1"].state
   "y":
     - $ex hass.states["number.presence_bureau_zone_1_y1"].state
     - $ex hass.states["number.presence_bureau_zone_1_y2"].state
     - $ex hass.states["number.presence_bureau_zone_1_y2"].state
     - $ex hass.states["number.presence_bureau_zone_1_y1"].state
     - $ex hass.states["number.presence_bureau_zone_1_y1"].state
 - entity: ""
   name: Zone 3
   mode: lines
   fill: toself
   fillcolor: RGBA(200,0,255,0.06)
   line:
     color: RGBA(200,0,255,0.2)
     shape: line
     width: 2
   x:
     - $ex hass.states["number.presence_bureau_zone_2_x1"].state
     - $ex hass.states["number.presence_bureau_zone_2_x1"].state
     - $ex hass.states["number.presence_bureau_zone_2_x2"].state
     - $ex hass.states["number.presence_bureau_zone_2_x2"].state
     - $ex hass.states["number.presence_bureau_zone_2_x1"].state
   "y":
     - $ex hass.states["number.presence_bureau_zone_2_y1"].state
     - $ex hass.states["number.presence_bureau_zone_2_y2"].state
     - $ex hass.states["number.presence_bureau_zone_2_y2"].state
     - $ex hass.states["number.presence_bureau_zone_2_y1"].state
     - $ex hass.states["number.presence_bureau_zone_2_y1"].state
 - entity: ""
   name: Salle de bain
   mode: lines
   fill: toself
   fillcolor: RGBA(200,120,55,0.06)
   line:
     color: RGBA(200,120,55,0.2)
     shape: line
     width: 2
   x:
     - $ex hass.states["number.presence_bureau_zone_3_x1"].state
     - $ex hass.states["number.presence_bureau_zone_3_x1"].state
     - $ex hass.states["number.presence_bureau_zone_3_x2"].state
     - $ex hass.states["number.presence_bureau_zone_3_x2"].state
     - $ex hass.states["number.presence_bureau_zone_3_x1"].state
   "y":
     - $ex hass.states["number.presence_bureau_zone_3_y1"].state
     - $ex hass.states["number.presence_bureau_zone_3_y2"].state
     - $ex hass.states["number.presence_bureau_zone_3_y2"].state
     - $ex hass.states["number.presence_bureau_zone_3_y1"].state
     - $ex hass.states["number.presence_bureau_zone_3_y1"].state
 - entity: ""
   name: Couverture
   mode: lines
   fill: tonexty
   fillcolor: rgba(168, 216, 234, 0.15)
   line:
     shape: line
     width: 1
     dash: dot
   x:
     - 0
     - $ex 7500 * Math.sin((2 * Math.PI)/360 * 60)
     - 4500
     - 4000
     - 3000
     - 2000
     - 1000
     - 0
     - -1000
     - -2000
     - -3000
     - -4000
     - -4500
     - $ex -7500 * Math.sin((2 * Math.PI)/360 * 60)
     - 0
   "y":
     - 0
     - $ex 7500 * Math.cos((2 * Math.PI)/360 * 60)
     - $ex Math.sqrt( 7500**2 - 4500**2 )
     - $ex Math.sqrt( 7500**2 - 4000**2 )
     - $ex Math.sqrt( 7500**2 - 3000**2 )
     - $ex Math.sqrt( 7500**2 - 2000**2 )
     - $ex Math.sqrt( 7500**2 - 1000**2 )
     - 7500
     - $ex Math.sqrt( 7500**2 - 1000**2 )
     - $ex Math.sqrt( 7500**2 - 2000**2 )
     - $ex Math.sqrt( 7500**2 - 3000**2 )
     - $ex Math.sqrt( 7500**2 - 4000**2 )
     - $ex Math.sqrt( 7500**2 - 4500**2 )
     - $ex 7500 * Math.cos((2 * Math.PI)/360 * 60)
     - 0
raw_plotly_config: true

Known issues

1. The LD2450 seems to have trouble detecting stationary targets, so I'm going to try adding an LD2412.
2. I thought I could use it for multiple rooms, but obstacles get in the way. I really recommend one sensor per room.
3. Apparently, if the sensor is disconnected, the zone configuration is lost. I'm thinking of writing a Home Assistant script to restore it.

In summary, I'm going to continue experimenting to improve the sensor while sticking with something affordable.