From 880794f966727399d5a2230520e2168f777a5d79 Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Tue, 10 Sep 2019 15:31:36 +0200
Subject: [PATCH] converter for twos-complement fixed decimal numbers

---
 src/Converters.py  | 13 +++++++++++++
 src/registers.json | 10 +++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/Converters.py b/src/Converters.py
index 05319a8..07f94fa 100644
--- a/src/Converters.py
+++ b/src/Converters.py
@@ -6,6 +6,14 @@
 from struct import pack, unpack
 
 
+def fix1twos(x):
+    x = x[0]
+    r = x
+    if x & 0x8000:
+        r = ((x - 1) ^ 0xffff) * -1
+    return r / 10
+      
+
 Converters = {
     "dht20TOFloat": {
         "in": lambda x : float(x[0]) / 10.0,
@@ -14,5 +22,10 @@ Converters = {
     "uint32": {
         "in": lambda x : unpack('L', pack('HH', *x))[0],
         "out": lambda x : unpack('HH', pack('L', int(x)))
+    },
+    "fix1twos": {
+        "in": lambda x: fix1twos(x),
+        "out": None
     }
 }
+
diff --git a/src/registers.json b/src/registers.json
index 0745362..401f6ce 100644
--- a/src/registers.json
+++ b/src/registers.json
@@ -90,7 +90,7 @@
     {
         "args": {
             "address": 1,
-            "converter": "dht20TOFloat",
+            "converter": "fix1twos",
             "count": 1,
             "label": "wago1",
             "publishTopic": "IoT/Measurement/Modbus2/Wago1",
@@ -103,14 +103,14 @@
     {
         "args": {
             "address": 0,
-            "converter": "dht20TOFloat",
+            "converter": "fix1twos",
             "count": 1,
-            "label": "wago0",
-            "publishTopic": "IoT/Measurement/Modbus2/Wago0",
+            "label": "Freezer",
+            "publishTopic": "IoT/Measurement/Modbus2/Freezer",
             "scanRate": 1.0,
             "unit": 11,
             "updateOnly": false
         },
         "type": "InputRegisterDatapoint"
     }
-]
\ No newline at end of file
+]