RE: https://mastodon.social/@Catfish_Man/115702435820394107

IKEA #ALPSTUGA med CO₂-sensor er ikke tilgjengelig i norsk IKEA. De vil vel selge ut det de har av #VINDSTYRKA først?

**Automating a dumb kitchen hood with Home Assistant**

(link to blog)

Last month I had to repair my kitchen hood – replace its PCB – and I got an idea how to automate it.

The idea is to turn it on automagically when something is cooking and the kitchen air gets stale. I already have a VOC sensor in the kitchen (Ikea Vindsyrka – see the blog post).

The hood was sold under the brand Respekta – which has same PCB as Baumatic an probably some other brands.

What else I need?

• something that presses the button on the hood instead of me.

Should I use fingerbot? Seems too clunky and limits the access to buttons. No.

Hardware

I figured out I need a ‘dry relay’ to make contact on the hood’s button. The device that only closes and opens the button’s circuit (without any voltage). I found 2 (zigbee):

• Aqara Dual channel T1 (~35€) and
• ZG-001(link to review on Smarthomescene), ~9€.

Firstly I thought I could use one of the spare Sonoff ZBminis I already had at hand, but they do not have a dry contact. There are some instructions on YT how to cut some contacts on its board, but I didn’t want to bother and ordered zg-001 switch.

The hood’s fan and light buttons are connected to the hood’s PCB via 5-wire cable. The port on the board is CN5:

After inspecting PCB from the bottom side, I saw that wires 1, 3, 4, 5 are connected to a chip and 2 to some resistor. So I thought that 2 must be GND and the others are control wires. I short circuited combinations of pin 2 and others and the fan turned on. Short circuiting wires 2 and 1 turns on the fan on the lowest speed – exactly what I need. I removed a bit of insulation on these two wires and soldered an extension wires:

Reconnected the connector to the PCB:

I also added one 230V cable for powering the dry relay switch. I put both cables through the hood’s ventilation holes. I could install the dry relay switch within the cover, but I wasn’t sure the zigbee signal will penetrate through it. So I decided I will mount it on the outside of the hood’s cover.

This hood’s covers are quite tricky to dismount and remount, I needed 2 people to help me.

Now I’m waiting for the dry contact relay to arrive.

Dry contact switch

The switch arrived and I mounted it on the outside of the hood. Connected 230V for power supply and wires for the parallel connection to the hood fan button/contact. This smart switch can also be powered with USB. Other models also with variable DC power sources (7-32V).

Home Assistant / zigbee2mqtt recognized it immediately after powering it on.

It shows up as Tuya ZG-001:

Home Assistant automation

Now, the automation.

Firstly, I need to simulate short hood button press. I achieved that with a simple automation that turns off smart switch 200ms after it detects it has been turned on:

Next, I want the hood turns on when the air in the kitchen is dirty (something is cooking).

I already have Ikea Vindstyrka (see the post) sensor nearby.

The automation turns on the hood for 2 minutes when it detects VOC is above 230 for 1 minute:

It’s very simple automation, but it works. It doesn’t matter if I cook something, baking in the oven or nearby toaster – it turns on because of increased VOC. That is good.

Some ideas for the future

The issue is that VOC is dropping slowly over time, even with hood turned on. I don’t want the hood runs for extended periods of time, because it is quite loud.

I have to figure out how how to solve this issue. One idea is to install another, IR sensor under the hood and capture HOB2HOOD signals from the hob and turn the hood off when the hob isn’t active. Will see how the current solution will work out.

Also, I’m not sure if VOC 230 is a good threshold. Maybe it would be better if I set-up thermostat like entity in Home Assistant so I (or other family members) can increase or decrease VOC threshold without changing the automation. Not sure how to implement this, because the hob switch reacts on a press, not on a on-off state.

https://blog.rozman.info/automating-a-dumb-kitchen-hood-with-home-assistant/

#homeassistant #hood #ikea #vindstyrka #zg001 #Zigbee

Home Assistant and air quality – Ikea Vindstyrka

The problem

I’d like to monitor air quality in my kitchen/dining room to ventilate the rooms more frequently. Sometimes I simply forget to open windows.

But again, there is no problem really. I just like to play with IoT gadgets and spend money on something else than drugs.

The ‘solution’

So I did a little ‘research’ on cheap air quality sensors and then decided to buy Ikea’s Vindstyrka (zigbee) device.

“But Tomi, you should trust your nose!” some might say. That’s true, but after breathing stale air for some time I don’t notice it anymore.

After some googling I found out I should monitor VOC (Volatile Organic Compounds) that are emitted (off-gassed) from paints, furniture, cleaning products, burning wood, mold, cooking, frying etc. [definition of VOC].

Also small particles (PM2.5) are worth to monitor. They are emmited by cooking (frying, burning food), candles, smoking, plants (pollen) and also by people (skin shedding) [sources of particulate matter].

This Ikea’s device detects both (tVOC – total VOC and PM2.5) besides temperature and relative humidity.

Installation

Installation was pretty straightforward. Firstly, I had to buy USB-C charger (1A) to power it. It comes only with an USB cable, charger is sold separately.

To connect it to my #zigbee network I had to press the big button on top 4x and then allowed the device to join to HomeAssistant/Zigbee2MQTT. Immediately it found a firmware update and installed it successfully OTA.

Long press to pair it to z2m doesn’t do the trick – although the link icon on the device display blinks, it’s purpose is to connect the device to other Ikea devices such as air purifier. I found out that after RTFM. So – use 4x press.

The first biggest issue was – where to place it, physically? Near the kitchen hood? Above the kitchen sink?

Firstly I put it on a kitchen shelf approx. 1.6m above the floor. It wasn’t the best idea, because this device is loud. I read before that the fan emmits audible buzz, but I didn’t expect I will hear it 7-8m far sitting on the couch. Finally it ended in an open narrow kitchen cabinet, directed away from the couch. Maybe the air flow is not so good there, but at least I can’t hear it anymore.

It will definitely not be used in the bedroom.

Adding it to Home Assistant

I’ve added it to my Home Assistant / Kitchen dashboard:

The device doesn’t show tVOCs (only a trend – stable, increasing, decreasing), but it reports values over zigbee (1-500). Nice!

How did I define the colours (severity) of the measurements on the Gauge?

tVOC index

tVOC index is a Sensirion’s way of measuring VOCs. I‘ve used documentation from Sensirion tVOC sensor and defined ranges: green: 1-150, yellow: 150-250, orange: 250-400 and red: 400-500.

Value of tVOC index is a moving average and 100 represent an average VOC concentration in last 24hr. So in a way mimics a human nose. The Sensirion’s image:

While trying to define colours for HA’s Gauge card I found out it can’t be defined using UI.

So I edited Gauge’s yaml and defined ranges of colours. See the other post >>

PM2.5 Gauge

For defining PM2.5 Gauge colours, I’ve used levels from Vindstyrka’s documentation (page 13): green: 0-35, yellow: 35-120, red: >120 ug/m3 (img):

First measurements

After 10 days or so I started to make sense out of measurements.

Temperatue and relative humidity: I noticed it doesn’t report temperature decimals, only whole numbers (20, 21C…). I don’t understand that design decision, because the cheapest Xiaomi BLE thermomethers report decimals and are .2 -.3 accurate. It bothers me somehow that 30€ device can’t report temp. decimals.

Relative humidity measurements are similar to other (Xiaomi BLE) sensors, +- 5%.

What about tVOC and PM2.5? I was most interested in these measurements.

tVOC index

tVOC increases when we cook. It increases more when we’re frying something, using an oven or using a toaster. Only cooking a soup doesn’t increase tVOC as much.

Opening windows decrease tVOCs quickly, 5 minutes are enough.

PM2.5

Small particles are elevated when cooking. There is more to it: sometimes PM2.5 increase when I open windows to ventilate. Now it’s winter and some neighbours use wood for heating, probably that’s the reason (img).

Automations

I don’t have an air purifyer or recuperation system, so my first automations related to air quality are quite simple.

This automation notifies FireHD tablet to say: “Warning, the air is dirty, open windows!” and also sends a text message to my and wife’s phone (img):

It works really good and our ventilation habits improved already.

I’m also playing with automation to turn on bathroom exhaust fan if tVOCs are increased. But the bathroom is on the other side of the house and I don’t know yet if it will have any effect.

Plans:

• Maybe I’ll smartify my kitchen hood to turn it on when the air is dirty. I ‘just’ have to figure out how to connect some esp32 to its fan buttons… and how to convert hood’s light 12V to 5V to power the esp32.
• Do I need CO2 sensor too? Probably yes, especially in the bedroom.

TL;DR

• it’s a cheap device (30€) in comparison with similar air quality sensors
• it works well with z2m and Home Assistant
• its fan is loud (imagine some angry flies trapped in a box)
• the temperature sensor returns only whole numbers, no decimals

Tags: #homeassistant #zigbee #z2m #zigbee2mqtt #ikea #vindstyrka #tvoc #pm25

If you’re reading this on fediverse and the layout (embedded pics) is off or missing, here’s the link to the original blog post.

https://blog.rozman.info/home-assistant-and-air-quality-ikea-vindstyrka/

#homeassistant #ikea #pm25 #tvoc #vindstyrka #z2m #Zigbee #Zigbee2MQTT

Cool, the #ikea #vindstyrka #airquality #sensor just works with #homeassistant and #deconz ;)

And it's a bit cheaper than most I've found.

#zigbee based. I hadn't even noticed it on the box.

https://www.ikea.com/be/en/p/vindstyrka-air-quality-sensor-smart-00498231/