Add step functionality to Zigbee curtains using Common Handler.

Author: zs

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-aqara-roller-shade-rotate.yml

@@ -6,6 +6,8 @@ components:
         version: 1
       - id: windowShadeLevel
         version: 1
+      - id: statelessWindowShadeLevelStep
+        version: 1
       - id: stse.initializedStateWithGuide
         version: 1
       - id: stse.shadeRotateState

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-aqara.yml

@@ -6,6 +6,8 @@ components:
         version: 1
       - id: windowShadeLevel
         version: 1
+      - id: statelessWindowShadeLevelStep
+        version: 1
       - id: stse.deviceInitialization
         version: 1
       - id: firmwareUpdate

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-battery.yml

@@ -8,6 +8,8 @@ components:
     version: 1
   - id: windowShadeLevel
     version: 1
+  - id: statelessWindowShadeLevelStep
+    version: 1
   - id: battery
     version: 1
   - id: firmwareUpdate

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-no-preset.yml

@@ -8,6 +8,8 @@ components:
     version: 1
   - id: windowShadeLevel
     version: 1
+  - id: statelessWindowShadeLevelStep
+    version: 1
   - id: firmwareUpdate
     version: 1
   - id: refresh

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-powerSource.yml

@@ -6,6 +6,8 @@ components:
         version: 1
       - id: windowShadeLevel
         version: 1
+      - id: statelessWindowShadeLevelStep
+        version: 1
       - id: windowShadePreset
         version: 1
       - id: powerSource

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-profile-no-firmware-update.yml

@@ -8,6 +8,8 @@ components:
     version: 1
   - id: windowShadeLevel
     version: 1
+  - id: statelessWindowShadeLevelStep
+    version: 1
   - id: refresh
     version: 1
   categories:

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-profile.yml

@@ -8,6 +8,8 @@ components:
     version: 1
   - id: windowShadeLevel
     version: 1
+  - id: statelessWindowShadeLevelStep
+    version: 1
   - id: firmwareUpdate
     version: 1
   - id: refresh

drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-reverse.yml

@@ -6,6 +6,8 @@ components:
     version: 1
   - id: windowShadeLevel
     version: 1
+  - id: statelessWindowShadeLevelStep
+    version: 1
   - id: windowShadePreset
     version: 1
   - id: firmwareUpdate

drivers/SmartThings/zigbee-window-treatment/src/hanssem/init.lua

@@ -25,8 +25,6 @@ local TUYA_CLUSTER = 0xEF00
 local DP_TYPE_VALUE = "\x02"
 local DP_TYPE_ENUM = "\x04"
 
-local SeqNum = 0
-
 -------- Send Command Function for Tuya Zigbee device -------------
 -- ZigbeeMessageTx:
 --    Uint16: 0x0000
@@ -45,6 +43,14 @@ local SeqNum = 0
 --        ReadAttribute:
 --            AttributeId: 0x0000
 
+-- Get next sequence number for Tuya commands (per-device storage to avoid counter conflicts)
+local function get_next_tuya_seq_num(device)
+  local seq = device:get_field("tuya_seq_num") or 0
+  seq = (seq + 1) % 65536
+  device:set_field("tuya_seq_num", seq)
+  return seq
+end
+
 local function SendCommand(device, DpId, Type, Value)
   local addrh = Messages.AddressHeader(
     ZigbeeConstants.HUB.ADDR, 					-- Source Address
@@ -57,8 +63,7 @@ local function SendCommand(device, DpId, Type, Value)
   local zclh = ZigbeeZcl.ZclHeader({cmd = data_types.ZCLCommandId(0x00)})
   zclh.frame_ctrl:set_cluster_specific()	-- sets this frame control field to be cluster specific
   -- Make a payload body
-  SeqNum = (SeqNum + 1) % 65536
-  local strSeqNum = string.pack(">I2", SeqNum)  -- Pack the Sequence number to 2 bytes unsigned integer type with big endian.
+  local strSeqNum = string.pack(">I2", get_next_tuya_seq_num(device))  -- Pack the Sequence number to 2 bytes unsigned integer type with big endian.
   local LenOfValue = string.pack(">I2",string.len(Value))  -- Pack length of Value to 2 bytes unsigned integer type wiht big endian.
   local PayloadBody = generic_body.GenericBody(strSeqNum .. DpId .. Type .. LenOfValue .. Value)
   local MsgBody = ZigbeeZcl.ZclMessageBody({zcl_header = zclh, zcl_body = PayloadBody})

drivers/SmartThings/zigbee-window-treatment/src/stateless_handler/can_handle.lua

@@ -0,0 +1,13 @@
+-- Copyright 2026 SmartThings, Inc.
+-- Licensed under the Apache License, Version 2.0
+
+local capabilities = require "st.capabilities"
+
+return function(opts, driver, device)
+  local can_handle = device:supports_capability(capabilities.statelessWindowShadeLevelStep)
+  if can_handle then
+    local subdriver = require("stateless_handler")
+    return true, subdriver
+  end
+  return false
+end