feat: Add ThermostatHello packet handling

- Add a log line of interest to error packet
- Define compressor_frequency as NaN to start

components/mitsubishi_uart/mitsubishi_uart-packetprocessing.cpp

@@ -301,12 +301,17 @@ void MitsubishiUART::processPacket(const ErrorStateGetResponsePacket &packet) {
   // TODO: Include friendly text from JSON, somehow.
   if (!packet.errorPresent()) {
     error_code_sensor->raw_state = "No Error Reported";
-  } else if (packet.getRawShortCode() != 0x00) {
+  } else if (auto rawCode = packet.getRawShortCode() != 0x00) {
+    // Not that it matters, but good for validation I guess.
+    if ((rawCode & 0x1F) > 0x15) {
+      ESP_LOGW(TAG, "Error short code %x had invalid low bits. This is an IT protocol violation!", rawCode);
+    }
+
     error_code_sensor->raw_state = "Error " + packet.getShortCode();
   } else if (packet.getErrorCode() != 0x8000) {
     error_code_sensor->raw_state = "Error " + to_string(packet.getErrorCode());
   } else {
-    // Logic bug :(
+    // Logic bug, should never happen.
     ESP_LOGW(TAG, "Packet indicated an error was present, but none of the error states matched. wat.");
   }
 

components/mitsubishi_uart/muart_bridge.cpp

@@ -180,8 +180,8 @@ void MUARTBridge::classifyAndProcessRawPacket(RawPacket &pkt) const {
       case SetCommand::settings :
         processRawPacket<SettingsSetRequestPacket>(pkt, true);
         break;
-      case SetCommand::a_7 :
-        processRawPacket<A7SetRequestPacket>(pkt, false);
+      case SetCommand::thermostat_hello :
+        processRawPacket<ThermostatHelloRequestPacket>(pkt, false);
         break;
       default:
         processRawPacket<Packet>(pkt, true);

components/mitsubishi_uart/muart_packet-derived.cpp

@@ -1,5 +1,6 @@
 #include "muart_packet.h"
 #include "mitsubishi_uart.h"
+#include "muart_utils.h"
 
 namespace esphome {
 namespace mitsubishi_uart {
@@ -70,6 +71,12 @@ std::string RemoteTemperatureSetRequestPacket::to_string() const {
   return ("Remote Temp Set Request: " + Packet::to_string() + CONSOLE_COLOR_PURPLE +
           "\n Temp:" + std::to_string(getRemoteTemperature()));
 }
+std::string ThermostatHelloRequestPacket::to_string() const {
+  return("Thermostat Hello: " + Packet::to_string() + CONSOLE_COLOR_PURPLE +
+          "\n Model: " + getThermostatModel() +
+          " Serial: " + getThermostatSerial() +
+          " Version: " + getThermostatVersionString());
+}
 
 // TODO: Are there function implementations for packets in the .h file? (Yes)  Should they be here?
 
@@ -262,6 +269,20 @@ std::string ErrorStateGetResponsePacket::getShortCode() const {
   return {upperAlphabet[(errorCode & 0xE0) >> 5], lowerAlphabet[lowBits]};
 }
 
+// ThermostatHelloRequestPacket functions
+std::string ThermostatHelloRequestPacket::getThermostatModel() const {
+  return MUARTUtils::DecodeNBitString((pkt_.getBytes() + 1), 3, 6);
+}
+
+std::string ThermostatHelloRequestPacket::getThermostatSerial() const {
+  return MUARTUtils::DecodeNBitString((pkt_.getBytes() + 4), 8, 6);
+}
+
+std::string ThermostatHelloRequestPacket::getThermostatVersionString() const {
+  char buf[9];
+  sprintf(buf, "%02d.%02d.%02d", pkt_.getPayloadByte(13), pkt_.getPayloadByte(14), pkt_.getPayloadByte(15));
+  return buf;
+}
 
 }  // namespace mitsubishi_uart
 }  // namespace esphome

components/mitsubishi_uart/muart_packet.h

@@ -356,12 +356,18 @@ class RemoteTemperatureSetResponsePacket : public Packet {
 };
 
 // Sent by MHK2 but with no response; defined to allow setResponseExpected(false)
-class A7SetRequestPacket : public Packet {
+class ThermostatHelloRequestPacket : public Packet {
   using Packet::Packet;
  public:
-  A7SetRequestPacket() : Packet(RawPacket(PacketType::set_request, 4)) {
-    pkt_.setPayloadByte(0, static_cast<uint8_t>(SetCommand::a_7));
+  ThermostatHelloRequestPacket() : Packet(RawPacket(PacketType::set_request, 4)) {
+    pkt_.setPayloadByte(0, static_cast<uint8_t>(SetCommand::thermostat_hello));
   }
+
+  std::string getThermostatModel() const;
+  std::string getThermostatSerial() const;
+  std::string getThermostatVersionString() const;
+
+  std::string to_string() const override;
 };
 
 // Sent by MHK2 but with no response; defined to allow setResponseExpected(false)

components/mitsubishi_uart/muart_rawpacket.h

@@ -43,7 +43,7 @@ enum class GetCommand : uint8_t {
 enum class SetCommand : uint8_t {
   settings = 0x01,
   remote_temperature = 0x07,
-  a_7 = 0xa7
+  thermostat_hello = 0xa7
 };
 
 // Which MUARTBridge was the packet read from (used to determine flow direction of the packet)

components/mitsubishi_uart/muart_utils.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "mitsubishi_uart.h"
+
+namespace esphome {
+namespace mitsubishi_uart {
+
+class MUARTUtils {
+ public:
+  static std::string DecodeNBitString(const uint8_t data[], size_t dataLength, size_t wordSize) {
+    auto resultLength = (dataLength / wordSize) + (dataLength % wordSize != 0);
+    auto result = std::string();
+
+    for (int i = 0; i < resultLength; i++) {
+      auto bits = BitSlice(data, i * wordSize, ((i + 1) * wordSize) - 1);
+      if (bits <= 0x1F) bits += 0x40;
+      result += (char)bits;
+    }
+
+    return result;
+  }
+
+ private:
+  static uint64_t BitSlice(const uint8_t ds[], size_t start, size_t end) {
+    // Lazies! https://stackoverflow.com/a/25297870/1817097
+    uint64_t s = 0;
+    size_t i, n = (end - 1) / 8;
+    for(i = 0; i <= n; ++i)
+      s = (s << 8) + ds[i];
+    s >>= (n+1) * 8 - end;
+    uint64_t mask = (((uint64_t)1) << (end - start + 1))-1;//len = end - start + 1
+    s &= mask;
+    return s;
+  }
+};
+
+}  // namespace mitsubishi_uart
+}  // namespace esphome