Components advise: AC shut-off via sensors

Hardware
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1

Hi folks,

I am about to start my first real ESP32 project and I’d love your help to confirm that I have selected the right components. I am very much open to improvements and by no means convinced that this is the best setup.

Use-case

some friends run a small hotel in Sri Lanka. They have just installed ACs. Many guests leave their room and keep the AC running, even though they are gone for the whole day. In a country where power is expensive and often limited, this is not a viable solution. My idea is to use presence detection to shut off the AC when there is no one in the room (with a grace period of eg. 15 minutes). Additionally, the AC should shut off when the balcony door is open, no matter if someone is in the room or not. The system should work standalone with a later (optional) integration into Home Assistant.

Presence detection

A ceiling-mounted mmWave sensor should be able to detect moving or barely moving (i.e. sleeping) people.

Door sensor

Endstop sensor with a small metal latch that is closed when the sliding door to the balcony is closed (and open when the door is open, duh).

AC control

Since the AC units are dumb, an IR transmitter should be able to turn off the unit via an IR command. I couldn’t find any IR commands for the units (AC: PN-CS-EU12AKY-8; remote: 6650-E(3X) or U6650-E24070100043) online so I will probably have to capture the necessary command(s) with a receiver (however, only once).

Brains

ESP32 connected to the 2 sensors and IR transmitter. Read sensor data and send command if condition(s) are met. Seems straightforward.

Components

Please let me know if these components work for my described use-case. Keep in mind that selection in Sri Lanka seems limited.

Since I brought a regular ESP32 dev. and an ESP32-C3 dev. I didn’t list them here.

Discarded sensors

Things that I considered but thought are not well-suited

  • PIR motion sensor (too imprecise when people are barely moving (sleeping)
  • Ultrasonic sensor (too susceptible to background noise, eg. AC or road noise)
  • CO-2 sensor (too slow to detect changes when someone enters the room)
  • Push button in lock (major mechanical changes needed to fit sensor and cables
  • Bluetooth BLE beacon (too many false positives due to rooms being very close to each other)

Thanks a lot, looking forward to your replies

2

Hi Stefan,

Is this related to Home Assistant at all?

3

Have a look at this for direct control without ir

I wouldn’t recommend ld2410s for commercial use, expect some interference like fans etc

There’s hlk ld6001 which has improved static detection and multiple zones

5

Have I picked the wrong forum? Wanted to use ESPHome for a quick and easy later integration into HA. Could also use Tasmota and MQTT but then this is definitely not the right place.
At a first step, I’d like to confirm that the components are sufficient

6

This looks amazing. Haven’t open the unit yet but will do asap. I assume it doesn’t have a WiFi adapter. So basically the esp32 can make it ‘smart’, even if it doesn’t have a pre-installed WiFI module? Installation looks pretty straight forward to me :slight_smile:
And would this be a correct logic converter?

The hlk ld6001 is quite a bit more expensive. Since we will need five of them it adds up. And you’re confident it’s worth the extra expense?

Thanks you very much

7

If your panasonic has cn_cnt or cn_wlan ports then it should work for you

Can’t say for sure other than this blog post

If you don’t have inteference in the room then you could just stick with ld2410

8

Well you didn’t mention HA or ESPHome until there.
That may have been helpful to lead with.

9

Fingers crossed that it does. Will open it up soon and then know more. Thanks a lot.

I’ll go with ld2410 for now but I do see what you mean. 60 GHz seems much better suited to detect human presence, especially in a small room.

10

True, that may have been helpful. Maybe I thought this wasn’t necessary since this is (might be) a HA/ESPHome community? Guess we will never know :slight_smile:

11

Unfortunately, I couldn’t identify the ports. Would you mind taking a look at the innards? Or direct me somewhere where I can find help?
AC pics

Thanks a lot

12

You need to remove the case, also check for any diagram