[SOLVED] Sonoff THR316D + WTS01 with Tasmota — Temperature reading + TM1621 display working

[marcosandreis]

Device: Sonoff THR316D (ESP32-D0WD-V3)
Sensor: WTS01 Waterproof Temperature Sensor (RJ11)
Firmware: tasmota32.bin v15.3.0
Goal: Read WTS01 temperature and show it on the TM1621 LCD display

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Problem

The WTS01 sensor does NOT work as DS18x20 or SI7021. It has an internal MCU that communicates via a proprietary serial protocol. Configuring GPIO25 as DS18x20 or SI7021 results in persistent null readings.

Also: using tasmota32-display.bin breaks the TM1621 display driver — use tasmota32.bin instead.

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Solution

Step 1 — Flash tasmota32.bin (NOT tasmota32-display)

Flash via browser: https://tasmota.github.io/install/ (Chrome only)

If already on tasmota32-display, reflash via Firmware Upgrade → file upload using tasmota32.bin

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Step 2 — Configure module

Go to Configuration → Configure Module:

• Module type: Sonoff THR316D (0)
• GPIO25: SerBr Rx

Save and reboot.

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Step 3 — Enable serial mode

In the Tasmota console, run once after reboot:

SSerialMode 3

Temperature should immediately appear in the SENSOR output:

{"WTS01":{"Temperature":22.9},"TempUnit":"C"}

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Step 4 — Enable TM1621 display

DspLine1 [WTS01#Temperature]
DspLine2 [WTS01#Temperature]

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Step 5 — Persist settings across reboots

Rule1 on system#init do Backlog SSerialMode 3; DspLine1 [WTS01#Temperature]; DspLine2 [WTS01#Temperature] endon
Rule1 1

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HTTP API (for external monitoring / Zabbix)

GET http:///cm?cmnd=Status%2010

JSONPath to extract temperature:

$.StatusSNS.WTS01.Temperature

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Notes

• Credit to @arendst for the SerBr Rx + SSerialMode 3 solution (v14.1.0.2+)
• Credit to @HectorDRR for the Berry driver that first cracked the WTS01 protocol
• The DspLine1 [WTS01#Temperature] syntax is required — [WTS01.Temperature] does NOT work
• Tested on THR316D with tasmota32.bin v15.3.0

Hope this helps others!

[lathyrus711-coder]

Thanks for your help.
With Tasmota 15.4.0, i also had to set GPIO27 to "Output Hi", in order to have supply for the WTS01 sensor. Here is my template, i hope this helps:
{"NAME":"Sonoff THR316D WTS01","ARCH":"ESP32","GPIO":[32,0,0,0,0,9280,0,0,0,321,0,576,320,9184,9216,0,0,224,0,9248,0,1824,0,3840,0,0,0,0,0,0,0,0,0,0,0,0],"FLAG":0,"BASE":1}