HIKING TOMZN DDS238-1 Wifi meter in Home Assistant

[Mowgly13]

Hello everyone.

I am using an HIKING TOMZN DDS238-1 Wifi ampermetric smart meter and I am trying to get it to work properly with Home Assistant, specifically to monitor the Amperage for Phase A and Phase B.

I have tried using both the official Tuya integration and the HACS Local Tuya integration, but the data displayed are completely wrong in both cases, It looks like they can't really understand the RAW Base64 or Hexadecimal data coming from this device.

I precise that the values appear perfectly in the SmartLife app.

I also tried the cloud-based HACS Tuya Sensors integration. This approach works, providing me with the raw hexadecimal value. I then apply a template filter to obtain the correct values. Unfortunately, with a 30-second refresh rate, I exhaust the free Tuya IoT Core monthly quota in just a few days, and the only paid tier available is $25,000 a year, which is obviously impossible for a personal home setup.

I am reaching out to see if anyone has encountered this issue and found a workaround to correctly decode these values in Home Assistant without hitting the cloud API limits.

Any ideas or guidance would be greatly appreciated.

Thank you!

[JamesG]

hi， Please provide your device ID, which can be found in the three dots at the top right corner of the app panel.

[Mowgly13]

Hi,

Device ID:
eba021d298e5a60f90xmaf

Thank you

[Mowgly13]

To clarify, the values are now pulled using the unofficial "Tuya Sensors" custom integration. It relies on the Tuya Cloud API, but I’m hitting the monthly quota limits, which are far too low for consistent monitoring. It only lasts for a few days during the month, and then it's stop working. That’s why I’m trying to decode the raw data to move toward a more reliable solution.

​The sensor provides a Base64 string in its attributes. Here is my current manual decoding procedure for Amperage:

​Example values received:
AAABpAAAAAAAAAAPxgl7
AAABqAAAAAAAAAAP9gl3

​Decoding steps:

1) Base64 to Hex: I convert the string to hexadecimal. For AAABqAAAAAAAAAAP9gl3, the result is 000001a80000000000000ff665d7.
2) Isolate Bytes: I target the bytes at index 11 and 12 (big-endian). In the example above, this is 0f f6.
3) Hex to Decimal: Converting 0ff6 to decimal gives 4086.
4) Scaling: Finally, I divide by 1000 to get 4.086 A.

​I am looking for a way to replicate this logic locally (via LocalTuya or similar) to bypass the cloud quota restrictions.

Ideally, a solution that provides direct values in Home Assistant without this Base64 decoding would be best. If any integration or configuration handles this processing internally, please let me know, as it would be a much more efficient way to manage my setup.

Has anyone else dealt with this specific byte mapping?

[JamesG]

The issue has been submitted to our internal technical team for processing.