MEL-AC lib for Mongoose OS

Mitsubishi Electric AC (air condition unit) and ATW (air to water unit) control by UART using amasing IoT platform - Mongoose OS

Inspired by great research made by Hadley Rich from New Zealand and SwiCago, who sorted all out and made an Arduino implementation and tutorial

Hardware

The protocol was sniffed from original Mitsubishi MAC-567IF-E controller:

Mitsubishi indoor unit's control board has CN105 (RED) connector for communication purposes. The communication performed by UART @ 2400 8E1 (5V TTL). The CN105 connector pinouts (1..5) = 12V, GND, 5V,TX, RX

RobotDyn WiFi-NodeM (ESP8266)

ESP-01 + 5V adapter (ESP8266)

Doit.am DevKit V1 (ESP32)

There are UART0 and UART2 available for this board

Compatability

All model coming with CN105 on an indoor unit's board, except PCA-RP71HAQ, PEA-RP400GAQ and PEA-RP500GAQ

More details available on MELCloud and KumoCloud pages

Mounting

IMPORTANT: When mounting the MEC-AC unit inside an indoor unit, refer to the installation manual of the indoor unit. Do not mount the Interface unit inside the indoor unit, if not mentioned

AC's indoor unit mount:

ATW's indoor unit mount:

Software

Comfig chema

"mel_ac": {
  "enable": true,         // Enable MEL-AC library
  "uart_no": 0,           // UART number
  "uart_baud_rate": 2400, // Do not change this, unless required
  "period_ms": 250,       // Packets handler timer, ms
  "rpc_enable": true      // Enable MEL-AC RPC handlers 
}

RPC

If RPC is present in your project, MEL-AC will add it's command handlers: MEL-AC.GetParams and MEL-AC.SetParams

$ mos --port mqtt://192.168.1.9/esp32_585E14 call RPC.list
[
    "MEL-AC.SetParams",
    "MEL-AC.GetParams",
    "Sys.SetDebug",
    "Sys.GetInfo",
    "Sys.Reboot",
    "RPC.Ping",
    "RPC.Describe",
    "RPC.List"
]

Read current params from HVAC

WebSockets

$ mos call --port ws://192.168.1.216/rpc MEL-AC.GetParams
{
"connected": true,
"power": 0,
"mode": 3,
"setpoint": 21.0,
"fan": 3,
"vane_vert": 0,
"vane_horiz": 3,
"isee": true,
"operating": false,
"room": 25.0
}

HTTP

http://192.168.1.216/rpc/MEL-AC.GetParams
{"connected": true, "power": 0, "mode": 1, "setpoint": 20.0, "fan": 2, "vane_vert": 0, "vane_horiz": 3, "isee": true, "operating": false, "room": 22.0}

MQTT

$ mos --port mqtt://192.168.1.9/esp32_585E14 call MEL-AC.GetParams 
{
"connected": true,
"power": 0,
"mode": 3,
"setpoint": 21.0,
"fan": 3,
"vane_vert": 0,
"vane_horiz": 3,
"isee": true,
"operating": false,
"room": 25.0
}

Set new params to HVAC

WebSockets

$ mos call --port ws://192.168.1.216/rpc MEL-AC.SetParams '{"mode":1,"fan":2,"setpoint":20}'
{
  "success": true,
  "power": 0,
  "mode": 1,
  "setpoint": 20.0,
  "fan": 2,
  "vane_vert": 0,
  "vane_horiz": 3
}

HTTP

$ curl -d '{"mode":1,"fan":2,"setpoint":20}' 192.168.1.216/rpc/MEL-AC.SetParams
{"success": true, "power": 0, "mode": 1, "setpoint": 20.0, "fan": 2, "vane_vert": 0, "vane_horiz": 3} 

MQTT

$ mos --port mqtt://192.168.1.9/esp32_585E14 call MEL-AC.SetParams '{"power":1,"mode":1,"fan":2,"setpoint":20}'
{
  "success": true,
  "power": 1,
  "mode": 1,
  "setpoint": 20.0,
  "fan": 2,
  "vane_vert": 0,
  "vane_horiz": 3
}

Primitives

The library init makes a timer is set up at mel_ac.period_ms milliseconds intervals to handle the device. The handler quering the HVAC params in a loop and sends new params when there are changes happen.

Events

Library triggering events as follows:

• MGOS_MEL_AC_EV_INITIALIZED: when the service initialized successfully
• MGOS_MEL_AC_EV_CONNECTED: when connected state changed. New state goes to *ev_data
• MGOS_MEL_AC_EV_PACKET_WRITE: after packet sent to HVAC
• MGOS_MEL_AC_EV_PACKET_READ: after new packet has been read from HVAC
• MGOS_MEL_AC_EV_PACKET_READ_ERROR: when there was a problem in packet from HVAC
• MGOS_MEL_AC_EV_PARAMS_CHANGED: when new changed params loaded from HVAC
• MGOS_MEL_AC_EV_ROOMTEMP_CHANGED: when room temperature change received from HVAC
• MGOS_MEL_AC_EV_TIMERS_CHANGED: when timers changed on HVAC
• MGOS_MEL_AC_EV_OPERATING_CHANGED: when operating state changed on HVAC
• MGOS_MEL_AC_EV_PARAMS_SET: when new params successfully set to HVAC
• MGOS_MEL_AC_EV_TIMER: before every service timer handler running
• MGOS_MEL_AC_EV_CONNECT_ERROR: when handshake packet returned error

To read params from HVAC

void mgos_mel_ac_get_params(struct mgos_mel_ac_params *params);

To write params to HVAC

bool mgos_mel_ac_set_power(enum mgos_mel_ac_param_power power);
bool mgos_mel_ac_set_mode(enum mgos_mel_ac_param_mode mode);
bool mgos_mel_ac_set_setpoint(float setpoint);
bool mgos_mel_ac_set_ext_temp(float temp);
bool mgos_mel_ac_set_fan(enum mgos_mel_ac_param_fan fan);
bool mgos_mel_ac_set_vane_vert(enum mgos_mel_ac_param_vane_vert vane_vert);
bool mgos_mel_ac_set_vane_horiz(enum mgos_mel_ac_param_vane_horiz vane_horiz);
void mgos_mel_ac_set_params(struct mgos_mel_ac_params *params);

Setters return false in case of invalid argument value

It's currently tested on ESP8266 and ESP32 platforms

For a complete demonstration of the driver, look at this Mongoose App

Larger project is mel-ac-homekit

Extra

A sample case 3D design for WiFi-NodeM:

Ready to print STL images available for top and bottom part