HLK-LD2450 Initial experiments to connect to HomeAssistant

update: Hlk improved a lot of firmware issues and also started mass production of ld2450, we designed separate enclosures and tested the firmware for up to a month, we are now sharing our sensors:
SCREEK wifi mmWave Human Presence Sensor 2A For Home Assistant (LD2450 esp32c3) | eBay

this is the first story info:

Hilink’s newly released LD2450 radar, which supports some interesting new features, including precise target location of three objects at the same time, looks like a cheap version of the fp2.

We got the radar about 3 weeks ago, we took six pieces of radar and we are interested if it brings new detection effects.

The demo of the OP was interesting, being able to show a person moving, the positioning looked quite ready and when we walked it would correspond to the activity.

The serial protocol is simple and we were able to do the serial reading with a simple esphome serial parsing function:

Note, however, that from the hardware we have received so far, there are some serious problems that make it very difficult to be used very simply, as in the case of the LD2410B:

  • The module seems to detect the RX level when it is powered up, and there must be a 5V high signal pull-up before it will start outputting data, otherwise there won’t be any output.
  • After the pull-up is completed, the module suddenly stops outputting after a long period of time, say a few hours, sometimes a few minutes. Unless the module is restarted, it does not get any output.
  • The module generates more heat, which, like the LD2410, seems to be a natural characteristic of HLK.

These are some of our initial findings, and because of the problems that occurred above, we paused to continue to try to perfect it. We recently reached out to the HLK developers and learned that a new OTA firmware is being refined that will address many of the instability issues.
We got the Android version for internal testing, but we don’t have any Android devices on hand, only IOS devices. Could not continue testing.

HLK is expected to release the IOS version of the OTA upgrade app this week.

We are looking forward to have further progress and see the result of its stability.

We got the firmware for the internal test and it’s very stable! We ran it for 3 days straight without any dropouts! We are still continuing to test.

Due to the current instability, we have suspended the idea of making it further into a sensor, but for interested esphome players, we can share our kit, including soldered wires with a bh1750 sensor, and the ld2450 radar.
If the new version of the firmware can solve the stability issue, we will further try to make a shell for it, just like we did before.

We will release our esphome profile soon, hopefully after the new firmware is stable.


Can I ask what is the external antenna for?
CleanShot 2023-06-06 at 19.12.44

This is the antenna for the Bluetooth function, unlike the LD2410b which uses a pcb antenna, this one uses a separate external antenna.

Currently the only open use of this Bluetooth feature is ota to upgrade the firmware.

Noted and thank you

We got the firmware for the internal test and it’s very stable! We ran it for 3 days straight without any dropouts! We are still continuing to test.

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Mind sharing the ESPHome code?

we will shard it soon! we are still test and Optimization, and test the new beta firmware.
it’s work pretty well in the test.
and we think we can soon share the hardware and yaml.


Where can I find that HiLink software?

there are a public custom lib (by tsunglung) for esphome now.

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the hilink site can download the software

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What about the bluetooth app? Does it use the same as LD2410B?

@screek-workshop It say’s: “The RX, TX need pull-up resistor”
Did you also used one in your testing?
Do you know what value of pull-up resistor is needed?

I tried the code by tsunglung on Github without the pull-up resistors. Seems to work but the output seems to be inaccurate, keep showing measurements above 3,000m even when I’m just in front of it, also the target resolution does change always 360mm. I don’t have a Windows PC, so i can’t compare the output with the HLK-2450 Tool.

the english version of the manual and tool: HLK-LD2450 Eng - Google Drive

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HLK told me that currently unable to update firmware via Bluetooth… Wonder why they included the Bluetooth in the current version of the hardware. Like LD2410B, doesn’t support OTA update.

Update, they informed me that:

You can see movement trajectory by bluetooth.

yes, as i know.ble can do the ota, as i ask the dev team, in the further them will be merge to the same app as ld2410.

How to check firmware and update firmware?

Edit: Updated the bluetooth app on my mobile and can see the firmware and updated it… Thanks

How to get Android app for LD2450?

Uploaded the APK to the Google drive above… That’s the old version, you will be prompted to update it when you run the app. Update using Wifi might have issues occasionally, but mobile network usually has no issues… Latest version is V1.1.18

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Would you say this LD2450 module is superior to the 1125H? Thanks