diff --git a/tools/rpi/hoymiles/decoders/__init__.py b/tools/rpi/hoymiles/decoders/__init__.py
index 1771a3e4..6836e73e 100644
--- a/tools/rpi/hoymiles/decoders/__init__.py
+++ b/tools/rpi/hoymiles/decoders/__init__.py
@@ -1,6 +1,9 @@
 #!/usr/bin/python3
 # -*- coding: utf-8 -*-
 import struct
+import crcmod
+
+f_crc_m = crcmod.predefined.mkPredefinedCrcFun('modbus')
 
 class StatusResponse:
     e_keys  = ['voltage','current','power','energy_total','energy_daily']
@@ -58,51 +61,148 @@ class UnknownResponse:
     def hex_ascii(self):
         return ' '.join([f'{b:02x}' for b in self.response])
 
+    @property
+    def valid_crc(self):
+        # check crc
+        pcrc = struct.unpack('>H', self.response[-2:])[0]
+        return f_crc_m(self.response[:-2]) == pcrc
+
     @property
     def dump_longs(self):
+        if len(self.response) < 5:
+            return None
+
         res = self.response
-        n = len(res)/4
+
+        r = len(res) % 16
+        res = res[:r*-1]
 
         vals = None
-        if n % 4 == 0:
+        if len(res) % 16 == 0:
+            n = len(res)/4
             vals = struct.unpack(f'>{int(n)}L', res)
 
         return vals
 
     @property
     def dump_longs_pad1(self):
-        res = self.response[1:]
-        n = len(res)/4
+        if len(self.response) < 7:
+            return None
+
+        res = self.response[2:]
+
+        r = len(res) % 16
+        res = res[:r*-1]
+
+        vals = None
+        if len(res) % 16 == 0:
+            n = len(res)/4
+            vals = struct.unpack(f'>{int(n)}L', res)
+
+        return vals
+
+    @property
+    def dump_longs_pad2(self):
+        if len(self.response) < 9:
+            return None
+
+        res = self.response[4:]
+
+        r = len(res) % 16
+        res = res[:r*-1]
+
+        vals = None
+        if len(res) % 16 == 0:
+            n = len(res)/4
+            vals = struct.unpack(f'>{int(n)}L', res)
+
+        return vals
+
+    @property
+    def dump_longs_pad3(self):
+        if len(self.response) < 11:
+            return None
+
+        res = self.response[6:]
+
+        r = len(res) % 16
+        res = res[:r*-1]
 
         vals = None
-        if n % 4 == 0:
+        if len(res) % 16 == 0:
+            n = len(res)/4
             vals = struct.unpack(f'>{int(n)}L', res)
 
         return vals
 
     @property
     def dump_shorts(self):
-        n = len(self.response)/2
+        if len(self.response) < 5:
+            return None
+
+        res = self.response
+
+        r = len(res) % 4
+        res = res[:r*-1]
 
         vals = None
-        if n % 2 == 0:
-            vals = struct.unpack(f'>{int(n)}H', self.response)
+        if len(res) % 4 == 0:
+            n = len(res)/2
+            vals = struct.unpack(f'>{int(n)}H', res)
+
         return vals
 
     @property
     def dump_shorts_pad1(self):
+        if len(self.response) < 6:
+            return None
+
         res = self.response[1:]
-        n = len(res)/2
+
+        r = len(res) % 4
+        res = res[:r*-1]
 
         vals = None
-        if n % 2 == 0:
+        if len(res) % 4 == 0:
+            n = len(res)/2
             vals = struct.unpack(f'>{int(n)}H', res)
+
         return vals
 
+class HM600_Decode11(UnknownResponse):
+    def __init__(self, response):
+        self.response = response
+
+        crc_valid = self.valid_crc
+        if crc_valid:
+            print(' payload has valid modbus crc')
+            self.response = response[:-2]
+
+        status = self.response[:2]
+
+        chunk_size = 12
+        for c in range(2, len(self.response), chunk_size):
+            chunk = self.response[c:c+chunk_size]
+            print(' '.join([f'{b:02x}' for b in chunk]) + ': ')
+            print(' BBLHl  : ' + str(struct.unpack('>BBLHl', chunk)))
+            print()
+
+class HM600_Decode12(HM600_Decode11):
+    def __init__(self, response):
+        super().__init__(response)
+
 class DEBUG_DecodeAny(UnknownResponse):
     def __init__(self, response):
         self.response = response
 
+        crc_valid = self.valid_crc
+        if crc_valid:
+            print(' payload has valid modbus crc')
+            self.response = response[:-2]
+
+        l_payload = len(self.response)
+        print(f' payload has {l_payload} bytes')
+
         longs = self.dump_longs
         if not longs:
             print(' type long      : unable to decode (len or not mod 4)')
@@ -115,6 +215,18 @@ class DEBUG_DecodeAny(UnknownResponse):
         else:
             print(' type long pad1 : ' + str(longs))
 
+        longs = self.dump_longs_pad2
+        if not longs:
+            print(' type long pad2 : unable to decode (len or not mod 4)')
+        else:
+            print(' type long pad2 : ' + str(longs))
+
+        longs = self.dump_longs_pad3
+        if not longs:
+            print(' type long pad3 : unable to decode (len or not mod 4)')
+        else:
+            print(' type long pad3 : ' + str(longs))
+
         shorts = self.dump_shorts
         if not shorts:
             print(' type short     : unable to decode (len or not mod 2)')