Fix zigbee attribute writes and configuration

tasmota/tasmota_xdrv_driver/xdrv_23_zigbee_5_2_converters.ino

@@ -278,10 +278,12 @@ uint8_t toPercentageCR2032(uint32_t voltage) {
 // Adds to buf:
 // - n bytes: value (typically between 1 and 4 bytes, or bigger for strings)
 // returns number of bytes of attribute, or <0 if error
+// If the value is `NAN`, the value encoded is the "zigbee invalid value"
 int32_t encodeSingleAttribute(SBuffer &buf, double val_d, const char *val_str, uint8_t attrtype) {
   uint32_t len = Z_getDatatypeLen(attrtype);    // pre-compute length, overloaded for variable length attributes
-  uint32_t u32 = val_d;
+  bool nan = isnan(val_d);
-  int32_t  i32 = val_d;
+  uint32_t u32 = nan ? 0xFFFFFFFF : roundf(val_d);
+  int32_t  i32 = roundf(val_d);
   float    f32 = val_d;
 
   switch (attrtype) {
@@ -315,13 +317,13 @@ int32_t encodeSingleAttribute(SBuffer &buf, double val_d, const char *val_str, u
 
     // signed 8
     case Zint8:      // int8
-      buf.add8(i32);
+      buf.add8(nan ? 0x80 : i32);
       break;
     case Zint16:      // int16
-      buf.add16(i32);
+      buf.add16(nan ? 0x8000 : i32);
       break;
     case Zint32:      // int32
-      buf.add32(i32);
+      buf.add32(nan ? 0x80000000 : i32);
       break;
 
     case Zsingle:      // float

tasmota/tasmota_xdrv_driver/xdrv_23_zigbee_8_parsers.ino

@@ -1594,7 +1594,7 @@ void Z_AutoConfigReportingForCluster(uint16_t shortaddr, uint16_t groupaddr, uin
         buf.add16(min_interval);
         buf.add16(max_interval);
         if (!Z_isDiscreteDataType(attr_matched.zigbee_type)) {   // report_change is only valid for non-discrete data types (numbers)
-          ZbApplyMultiplier(report_change, attr_matched.multiplier, attr_matched.divider, attr_matched.base);
+          ZbApplyMultiplierForWrites(report_change, attr_matched.multiplier, attr_matched.divider, attr_matched.base);
           // encode value
           int32_t res = encodeSingleAttribute(buf, report_change, "", attr_matched.zigbee_type);
           if (res < 0) {

tasmota/tasmota_xdrv_driver/xdrv_23_zigbee_A_impl.ino

@@ -219,18 +219,20 @@ void zigbeeZCLSendCmd(class ZCLFrame &zcl) {
 
 // Definitive doc for Tuya protocol:
 // https://developer.tuya.com/en/docs/iot-device-dev/tuya-zigbee-universal-docking-access-standard?id=K9ik6zvofpzql#subtitle-6-Private%20cluster
-// Special encoding for multiplier:
+
+// Special encoding for multiplier when sending writes or reportable attributes,
+// I.e. multipliers and dividers are inversed
 // multiplier == 0: ignore
 // multiplier == 1: ignore
-void ZbApplyMultiplier(double &val_d, int8_t multiplier, int8_t divider, int8_t base) {
+void ZbApplyMultiplierForWrites(double &val_d, int8_t multiplier, int8_t divider, int8_t base) {
+  if (0 != base) {
+    val_d = val_d - base;
+  }
   if ((0 != multiplier) && (1 != multiplier)) {
-    val_d = val_d * multiplier;
+    val_d = val_d / multiplier;
   }
   if ((0 != divider) && (1 != divider)) {
-    val_d = val_d / divider;
+    val_d = val_d * divider;
-  }
-  if (0 != base) {
-    val_d = val_d + base;
   }
 }
 
@@ -243,7 +245,7 @@ bool ZbTuyaWrite(SBuffer & buf, const Z_attribute & attr) {
 
   if (attr.key_is_str || attr.key_is_cmd) { return false; }    // couldn't find attr if so skip
   if (attr.isNum()) {
-    ZbApplyMultiplier(val_d, attr.attr_multiplier, attr.attr_divider, 0);
+    ZbApplyMultiplierForWrites(val_d, attr.attr_multiplier, attr.attr_divider, 0);
   }
   uint32_t u32 = val_d;
   int32_t  i32 = val_d;
@@ -302,7 +304,7 @@ bool ZbAppendWriteBuf(SBuffer & buf, const Z_attribute & attr, bool prepend_stat
 
   if (attr.key_is_str && attr.key_is_cmd) { return false; }    // couldn't find attr if so skip
   if (attr.isNum()) {
-    ZbApplyMultiplier(val_d, attr.attr_multiplier, attr.attr_divider, 0);
+    ZbApplyMultiplierForWrites(val_d, attr.attr_multiplier, attr.attr_divider, 0);
   }
 
   // push the value in the buffer
@@ -419,9 +421,14 @@ void ZbSendReportWrite(class JsonParserToken val_pubwrite, class ZCLFrame & zcl)
       // read ReportableChange
       JsonParserToken val_attr_rc = attr_config[PSTR("ReportableChange")];
       if (val_attr_rc) {
-        val_d = val_attr_rc.getFloat();
+        // If value is `null` then we send 0xFFFF for invalid value
         val_str = val_attr_rc.getStr();
-        ZbApplyMultiplier(val_d, attr.attr_multiplier, attr.attr_divider, 0);
+        if (!val_attr_rc.isNull()) {
+          val_d = val_attr_rc.getFloat();
+          ZbApplyMultiplierForWrites(val_d, attr.attr_multiplier, attr.attr_divider, 0);
+        } else {
+          val_d = NAN;
+        }
       }
 
       // read TimeoutPeriod