Battery and ESPEasy powered air monitor

[chromo23]

I wanted to introduce my most recent ESPEasy project.
Unfortunately my body doesn't like sitting in front of the computer at all lately, so i'll keep it short:

I really like my old CO2 monitor as it is very simple and easy to use, but it uses an MZH19 and is therefore not suitable for a battery powered project.
This is where the Scd41 sensor shines, with the added benefit of a temperature and humidity sensor. And as I had an Ens160 lying around, I made good use of it.

Features:
- ESP32S23 supermini with an integrated charge controller
- Scd41 CO2 sensor
- Ens160 VOC sensor
- 2 neopixels representing the air quality of each sensor
- 1 OLED display
- LDR to adjust the brightness of the neopixels
- A buzzer to provide audible feedback for the touch button and alarm
- A touch button on the top for waking up, scrolling through data on the OLED and starting an access point.

Pictures:

Old sensor:

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New sensor:

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[TD-er]

Looks really good!

[Rob73]

How are you managing the module to run on batteries? Do you keep it awake the whole time or are you putting it to sleep and wake it up in intervals?

I am wanting to run a small module on batteries and charge with solar. I am wanting to keep the esp module alive somewhat to catch switch/button inputs. Is there a way to just shut down the whole wifi radio and just keep the esp module alive and awake? Then wake up, say every hour or whenever and send the time of the last switch/button press? This is a new area I am tiptoeing into and I dont really have any experience with putting them to sleep and the whole battery thing. If the esp can stay alive & shut down the radio, that would work good for my weather station, catching pulses from the anemometer, then just reporting every so often what the readings are.

It looks super confusing because of the assortment of batteries, holders, charging circuits, solar panel options.

Rob

[chemmex]

I wanted to introduce my most recent ESPEasy project.

Really a nice looking stuff!

[chemmex]

How are you managing the module to run on batteries?

The general strategy is to put the ESP asleep and wake up either by timer or by hardware interrupt, i e a button switch connected to the gpio pin. In deep sleep the mcu disables the radio and may consume just several microamps, so If the board is designed properly, you can concentrate on optimizing the active time consumption.
I am not particularly sure if the ESPEasy supports waking up by hardware interrupts as I mainly use the timer mode. However, it is absolutely supported in Arduino and ESP-IDF.

It looks super confusing because of the assortment of batteries, holders, charging circuits, solar panel options

That's correct, basically, the panel should fit the charger while the battery capacity must be sufficient to sustain the weather changes, so there's quite a number of variables to consider. If you are designing a solar powered device or choosing the components to build it, you should start from calculating the power consumption of all components, and then choose the battery, charger, and panel.
In fact, there are not so many to choose from on the market, and hopefully there is a board with everything integrated, so you only need to buy compatible panel and battery. I was positively surprised by Waveshare's ESP32-S3 LTE board which completely fit my expectations and worked with my panel out of the box

[chromo23]

How are you managing the module to run on batteries? Do you keep it awake the whole time or are you putting it to sleep and wake it up in intervals?

Correct. When I unplug the power cable the air monitor automatically detects this and switches to low power mode. This means sensor readings for 3 minutes to stabilize the VOC readings and then it powers down for 10 minutes (all done with rules).
It is still possible to wake the device with the touch sensor in between. For now this is the only way to wake up an ESPEasy device with a GPIO.

Is there a way to just shut down the whole wifi radio and just keep the esp module alive and awake?

I don't think there is a way to turn only WiFi off but if I remember correctly it is on TD-er's todo list. (Which would be a really cool addition)

If the esp can stay alive & shut down the radio, that would work good for my weather station, catching pulses from the anemometer, then just reporting every so often what the readings are.

That would definitely work then. I was surprised how well a cheap charging module connected to a solar cell worked for my LoRa beehive scale and LoRa weather station.