diff --git a/CHANGELOG.md b/CHANGELOG.md
index c2d16fcd1..879cb98f5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ All notable changes to this project will be documented in this file.
 - Berry provide lightweight options for `tasmota.wifi/eth/memory/rtc` (#20448)
 - Berry `tasmota.webcolor` (#20454)
 - Support for pipsolar inverter (#20408)
+- Berry `debug.caller`
 
 ### Breaking Changed
 
diff --git a/lib/libesp32/berry/src/be_byteslib.c b/lib/libesp32/berry/src/be_byteslib.c
index 8d351997d..221e3e2a4 100644
--- a/lib/libesp32/berry/src/be_byteslib.c
+++ b/lib/libesp32/berry/src/be_byteslib.c
@@ -1768,6 +1768,7 @@ void be_load_byteslib(bvm *vm)
         { "clear", m_clear },
         { "reverse", m_reverse },
         { "copy", m_copy },
+        { "append", m_connect },
         { "+", m_merge },
         { "..", m_connect },
         { "==", m_equal },
@@ -1815,6 +1816,7 @@ class be_class_bytes (scope: global, name: bytes) {
     clear, func(m_clear)
     reverse, func(m_reverse)
     copy, func(m_copy)
+    append, func(m_connect)
     +, func(m_merge)
     .., func(m_connect)
     ==, func(m_equal)
diff --git a/lib/libesp32/berry/src/be_debuglib.c b/lib/libesp32/berry/src/be_debuglib.c
index fac4bfb53..2e4ee9bf4 100644
--- a/lib/libesp32/berry/src/be_debuglib.c
+++ b/lib/libesp32/berry/src/be_debuglib.c
@@ -13,6 +13,7 @@
 #include "be_debug.h"
 #include "be_map.h"
 #include "be_vm.h"
+#include "be_exec.h"
 #include <string.h>
 
 #if BE_USE_DEBUG_MODULE
@@ -103,6 +104,26 @@ static int m_traceback(bvm *vm)
     be_return_nil(vm);
 }
 
+static int m_caller(bvm *vm)
+{
+    int depth = 1;
+    if (be_top(vm) >= 1 && be_isint(vm, 1)) {
+        depth = be_toint(vm, 1);
+        if (depth < 0) {
+            depth = -depth;         /* take absolute value */
+        }
+    }
+    bcallframe *cf = (bcallframe*)be_stack_top(&vm->callstack) - depth;
+    bcallframe *base = be_stack_base(&vm->callstack);
+    if (cf >= base) {
+        bvalue *reg = be_incrtop(vm);
+        var_setval(reg, cf->func);
+        be_return(vm);
+    } else {
+        be_return_nil(vm);
+    }
+}
+
 #if BE_USE_DEBUG_HOOK
 static int m_sethook(bvm *vm)
 {
@@ -236,6 +257,7 @@ be_native_module_attr_table(debug) {
     be_native_module_function("varname", m_varname),
     be_native_module_function("upvname", m_upvname)
 #endif
+    be_native_module_function("caller", m_caller),
     be_native_module_function("gcdebug", m_gcdebug)
 };
 
@@ -252,6 +274,7 @@ module debug (scope: global, depend: BE_USE_DEBUG_MODULE) {
     top, func(m_top)
     varname, func(m_varname), BE_DEBUG_VAR_INFO
     upvname, func(m_upvname), BE_DEBUG_VAR_INFO
+    caller, func(m_caller)
     // individual counters
     allocs, func(m_allocs)
     frees, func(m_frees)
diff --git a/lib/libesp32/berry/tests/bytes.be b/lib/libesp32/berry/tests/bytes.be
index 4621747b1..c4d4af3f6 100644
--- a/lib/libesp32/berry/tests/bytes.be
+++ b/lib/libesp32/berry/tests/bytes.be
@@ -110,13 +110,20 @@ assert(str(b) == "bytes('AA')")
 b = b1 + '01'
 assert(str(b) == "bytes('AA3031')")
 
-#- .. -#
+#- .. and append as synonym-#
 b1 = bytes("1122")
 b2 = bytes("334455")
 b = b1..b2
 assert(str(b1) == "bytes('1122334455')")
 assert(str(b2) == "bytes('334455')")
 assert(str(b) == "bytes('1122334455')")
+#
+b1 = bytes("1122")
+b2 = bytes("334455")
+b = b1.append(b2)
+assert(str(b1) == "bytes('1122334455')")
+assert(str(b2) == "bytes('334455')")
+assert(str(b) == "bytes('1122334455')")
 
 #- .. with string -#
 b1 = bytes("AA")
@@ -124,6 +131,12 @@ b1 .. ''
 assert(str(b1) == "bytes('AA')")
 b1 .. '01'
 assert(str(b1) == "bytes('AA3031')")
+#
+b1 = bytes("AA")
+b1.append('')
+assert(str(b1) == "bytes('AA')")
+b1.append('01')
+assert(str(b1) == "bytes('AA3031')")
 
 #- item -#
 b = bytes("334455")
diff --git a/lib/libesp32/berry/tests/debug.be b/lib/libesp32/berry/tests/debug.be
index 9e732f6c3..88b559d81 100644
--- a/lib/libesp32/berry/tests/debug.be
+++ b/lib/libesp32/berry/tests/debug.be
@@ -1,4 +1,29 @@
 import debug
 
 class A end
-debug.attrdump(A)   #- should not crash -#
\ No newline at end of file
+debug.attrdump(A)   #- should not crash -#
+
+# debug.caller()
+def caller_name_chain()
+    import debug
+    import introspect
+    var i = 1
+    var ret = []
+    var caller = debug.caller(i)
+    while caller
+        ret.push(introspect.name(caller))
+        i += 1
+        caller = debug.caller(i)
+    end
+    return ret
+end
+var chain = caller_name_chain()
+assert(chain[0] == 'caller_name_chain')
+
+def guess_my_name__()
+    return caller_name_chain()
+end
+chain = guess_my_name__()
+print(chain)
+assert(chain[0] == 'caller_name_chain')
+assert(chain[1] == 'guess_my_name__')