Getting Started with XIAO Soil Moisture Sensor | Seeed Studio Wiki

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Getting Started with XIAO Soil Moisture Sensor | Seeed Studio Wiki

Getting Started with XIAO Soil Moisture Sensor

https://wiki.seeedstudio.com/XIAO_Soil_Moisture_Sensor/

[toddkrein]

I can't get HA to talk with my Soil Monitor. I've got the stock unit. I got it on my network, and HA sees it. When I try to add it, I get the message "Unable to connect to the ESPHome device. Make sure the device's YAML configuration includes an 'api' section."

I have no idea what to do next.
I've downloaded the YAML from this page, but I don't know how to get that into/onto HA, which is running on a HA Green board.

[toddkrein]

I did finally get it to work, but I cannot believe it was the optimal way. I installed and enabled the SSH app, and then copied the YAML from this page to the ESPBuilder directory and renamed it.

I can't believe that HA expects the typical user to be fluent in SHH and SCP.

[MediaArtsDad]

For others who run across this, I found that a quick reboot after I got the api error, and then it would accept it and work as advertised. No SSH or editing is required, at least with the current version shipping in August 2026.

[Arvics]

I can confirm exactly the same behaviour.
I followed all instructions, and it’s simply not possible to connect the device to HA. You also can’t reflash it directly, because ESPHome fails at compilation. The error is explicit: the platform attempts to download ESP‑IDF v5.2.1 from a URL that no longer exists (404).

This is a known issue with the mnowak32 platform fork for the XIAO ESP32‑C6.
A lot has changed in ESPHome’s codebase in 2026 — it’s time to update your packages.

[Lukilyy]

Hello, thank you for your feedback. We will review the current ESPHome configuration and dependency versions used in the Wiki, and verify their compatibility with the latest ESPHome version. If necessary, we will update the relevant documentation and example configurations.

Thank you again for your reminder. This version has been very helpful in addressing the compatibility issues for us.

[lfilipe-fe]

I had the same issue, you guys should check you are using AA batteries.
Question- Is it normal that the device disconnects from network after a couple of minutes? Does it only connect a few times a day to save batterie?

[technerd88]

Normal for the device to go to sleep and then wake up connect to the network and send sensor readings.

[technerd88]

Works as described. I am using the default firmware. Installed via https://gadgets.seeed.cc/
Not sure on the actual sleep cycles are for the factory firmware based on soil conditions but time will tell.

Tried to compile the home assistant yaml but ESPHOME latest Home Assistant app would not compile. This appears to be a ESPHOME add-on issue related to the version of the idf/board used.

[technerd88]

Just for clarification: If the factory code follows the above HA code:

• id: check_moisture_once
  then:
  • lambda: |-
    for(int i = 0; i < 10; i++){
    id(soil_sensor).update();
    delay(200);
    }
    float moisture = id(soil_sensor).state;
    ESP_LOGI("moisture_check", "Moisture reading: %f", moisture);
    float Diff = id(dry_value) - id(wet_value);
    ESP_LOGI("moisture_check", "Diff is: %f", Diff);
    ESP_LOGI("moisture_check", "ref_dry Diff is: %f",id(dry_value) - Diff * id(ref_dry));
    ESP_LOGI("moisture_check", "ref_wet Diff is: %f",id(dry_value) - Diff * id(ref_wet));
    if (moisture >= (id(dry_value) - Diff * id(ref_dry))) { // The drier -> the higher the voltage
    id(red_led_blink_3_times).execute();
    id(deep_sleep_control).set_sleep_duration(900000);
    } else if(moisture > (id(dry_value) - Diff * id(ref_wet)) && moisture < (id(dry_value) - Diff * id(ref_dry))){
    id(yellow_led_blink_3_times).execute();
    id(deep_sleep_control).set_sleep_duration(3600000);
    }else{
    // moisture > (id(dry_value) - Diff * id(ref_wet))
    id(green_led_blink_3_times).execute();
    id(deep_sleep_control).set_sleep_duration(28800000);
    }

The sleep durations are listed as 900000, 3600000 and 28800000 based on the moisture level.

[Midnitte]

So far these seem to be working as expected (just need to do a calibration once my soil is dry).

My only recommendation so far is that the finished product has water resistant casing (which I'd imagine is planned). For now I guess Ill just use a sandwich bag with a rubber band lol

[Midnitte]

Also seems like the battery is hard to remove and also dies rather quickly - I'd agree that using some AA batteries might be a good idea

[toddkrein]

Agreed on the non-water-tight case being a problem. The button press for immediate readings isn't useful to me, so I'd be much happier with a water-tight housing, with no openiengs.

The battery life awful. I get about 8 - 9 days on a brand-new AA battery.

[toddkrein]

How do you calibrate it?

[CrazyCoder]

If anyone is interested, I made a power efficient firmware for this soil sensor that can last 600+ days (or even more depending on the schedule):

https://github.com/CrazyCoder/xiao-soil-moisture-esphome

It wakes for less than 3 seconds and fixes a lot of known issues in the official firmware.

[MediaArtsDad]

Thank you for your work on this, this is awesome. Great documentation, easy to follow, and is working great.