fix d8200 with split binary, correct modbus addresses (#36)

* fix d8200 with split binary, correct modbus addresses

* slow down

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: untzag

CHANGELOG.md

@@ -5,6 +5,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/).
 
 ## [Unreleased]
 
+## [2024.2.0]
+
+### fixed
+- d8200 uses split binary, not twos-complement
+
 ## [2023.11.0]
 
 ### Added

yaqd_omega/_omega_d8200.py

@@ -1,5 +1,3 @@
-__all__ = ["OmegaPlatinum"]
-
 import asyncio
 from typing import Dict, Any, List
 import struct
@@ -12,19 +10,9 @@
 
 stop_bit_options = {"one": 1, "one_and_half": 1.5, "two": 2}
 
-CHANNEL_REGISTERS = dict()
-CHANNEL_REGISTERS[0] = 49
-CHANNEL_REGISTERS[1] = 50
-CHANNEL_REGISTERS[2] = 51
-CHANNEL_REGISTERS[3] = 52
-CHANNEL_REGISTERS[4] = 53
-CHANNEL_REGISTERS[5] = 54
-CHANNEL_REGISTERS[6] = 55
-
 
 # https://assets.omega.com/manuals/M5442.pdf
 #   as far as I can tell, the registers in this manual are wrong
-#   subtract 40,000 decimal from all registers
 class OmegaD8200(UsesUart, UsesSerial, IsSensor, IsDaemon):
     _kind = "omega-d8200"
 
@@ -55,12 +43,13 @@ async def _update_measurements(self):
         while True:
             await asyncio.sleep(0.5)
             out = dict()
-            for index in range(7):
-                register = CHANNEL_REGISTERS[index]
-                raw = self.client.read_register(register, functioncode=3)
-                current = (raw * (0.040 / 2**16)) + 0.020
-                out[f"channel{index}"] = current
-                self._measurement_id += 1
-                out["measurement_id"] = self._measurement_id
-                await asyncio.sleep(0)
+            rawl = self.client.read_registers(48, 7, functioncode=3)
+            # data is stored as offset binary
+            # by xoring into 0x80_00, I can convert into twos complement shorts
+            shortl = [i ^ 0x80_00 for i in rawl]
+            intl = [struct.unpack(">h", b.to_bytes(2, "big"))[0] for b in shortl]
+            for i, integer in enumerate(intl):
+                out[f"channel{i}"] = integer * (0.04 / 2**16)
+            out["measurement_id"] = self._measurement_id
+            self._measurement_id += 1
             self._measured = out