Control a Panasonic, Midea, Carrier, Fujitsu or Mitsubishi heat pump/split unit air conditioner with Arduino using a Windows Phone 8 application, or directly using UDP broadcasts Currently supports at least these models

• Panasonic E9/E12-CKP (Panasonic remote control P/N A75C2295)
• Panasonic E9/E12-DKE (Panasonic remote control P/N A75C2616)
• Panasonic E9/E12-JKE and E9/E12-NKE
• Midea MSR1-12HRN1-QC2 + MOA1-12HN1-QC2, sold as Ultimate Pro Plus Basic 13FP in Finland (Midea remote control P/N RG51M1/E)
• Carrier 42NQV035G / 38NYV035H2 (Carrier remote control P/N WH-L05SE)
• Fujitsu Nocria AWYZ14 (remote control P/N AR-PZ2)
• Mitsubishi MSZ FD-25, probably also FD-35 (remote control P/N KM09D 0052376)

For the Windows Phone 8 application source, see my other repository https://github.com/ToniA/wp8-heatpumpcontrol

• Compile the software, and program your Arduino
  • Note that the schema creates a random MAC address, and uses DHCP
  • Note that for watchdog to work, you need Adaboot (see the source for links)
• Wire up your Arduino as instructed in the schema
  • Ethernet connection to a switch
  • You can power the device for example with a USB cellphone charger (like Nokia AC-16E)
• Place the IR led so that the IR receiver on the indoor unit can see it
• Use the Windows Phone app to search for heatpump controllers :)

You can also use this directly by using UDP messages. The software will send a UDP reply to the sender's IP address and port if the 'channel' is not defined.

Examples:

echo '{"command":"identify"}' | socat -v - UDP4:192.168.0.255:49722,broadcast

echo '{"command":"command","fan":4,"identity":"02:26:89:28:25:C5","mode":2,"model":"panasonic_ckp","power":1,"temperature":24}' | socat -v - UDP4:192.168.0.255:49722,broadcast

And here's a piece of Python code:

from socket import *
sock = socket(AF_INET, SOCK_DGRAM)
sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
sock.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)

# Ask for the identity
sock.sendto('{"command":"identify"}', ('255.255.255.255', 49722))
data, addr = sock.recvfrom(2048) # buffer size is 1024 bytes
print "message from %s: %s" % (addr, data)

# Send a command to a controller
sock.sendto('{"command":"command","fan":4,"identity":"02:26:89:28:25:C5","mode":2,"model":"panasonic_ckp","power":1,"temperature":24}', ('255.255.255.255', 49722))
data, addr = sock.recvfrom(2048) # buffer size is 1024 bytes
print "message from %s: %s" % (addr, data)

The output is

message from ('192.168.0.12', 49722): {"command":"identify","identity":"02:26:89:28:25:C5"}
message from ('192.168.0.12', 49722): {"command":"command","fan":4,"identity":"02:26:89:28:25:C5","mode":2,"model":"panasonic_ckp","power":1,"temperature":24}

... and a similar program in Perl using the 'Socket' library

use Socket;

socket( SOCKET, PF_INET, SOCK_DGRAM, getprotobyname("udp") );

my $broadcastAddr = sockaddr_in( 49722, INADDR_BROADCAST );
setsockopt( SOCKET, SOL_SOCKET, SO_REUSEADDR, 1 );
setsockopt( SOCKET, SOL_SOCKET, SO_BROADCAST, 1 );

send( SOCKET, '{"command":"command","fan":2,"identity":"02:26:89:28:25:C5","mode":2,"model":"panasonic_ckp","power":1,"temperature":16}', 0,  $broadcastAddr );

my $input;
my $sockaddr = recv( SOCKET, $input, 2048, 0 );
my ($port, $ip_address) = unpack_sockaddr_in($sockaddr);

print inet_ntoa($ip_address) . " => $input\n";

close SOCKET;

Bill of materials

• Arduino :)
  • I'm using the Duemilanove, other models might require changes due to differences on the PWM pins. I hace code to drive the IR on PWM pin 46 (with timer5) on the Arduino Mega
  • Don't try this with Arduino's with ATmega168, 1k of SRAM just isn't enough
• Arduino Ethernet shield
• IR led
• 100 Ohm resistor for the IR led
  • The range is not very impressive this way, just a couple of meters
  • For higher output, use a ultra-bright IR led, and an amplifier (Arduino just drives a transistor which drives the IR led)

Connect an IR led (with 100 Ohm resistor in series) between GND and digital pin 3 (the schema now uses pin 9).