Anyone who has tried  controlling an Air Conditioner unit using an Arduino, USB IR Toy, RPi or any MCU will know how difficult it can be to record the longer infrared signals they use. Typical TV systems use IR signals circa 32 bits long, while this Chigo AC unit uses a signal with 197 marks & spaces (or 97 data bits). One of our users, Sertunc – from Istanbul in Turkey, reported his success using AnalysIR to easily record the signal timings for his AC unit and sent us the details along with some nice photos. After testing the validity of the recorded signals using an Arduino, he then set about loading the signals onto his Samsung smart phone (models S4, s4 mini, S5 and more supported). This was helped by installing the free ‘Samsung IR – Universal Remote‘ app onto his phone via Google Play.

The image on the left above shows the main user interface on the smart phone. The image on the right shows the configuration screen, with the IR signal exported from AnalysIR in Global Caché format.

The first step was to record the signals into AnalysIR using an Arduino equipped with an IR receiver. AnalysIR comes supplied with the firmware sketch for most Arduinos which are then connected to AnalysIR via USB on the Windows PC. AnalysIR also has a feature to automatically generate the ‘C’ required for the IRLib or IRremote libraries. Sertunc first decided to test his newly acquired AC signals using the IRLib library on his Arduino using the automatically generated ‘C’ code (see code below). Similarly, any recorded or imported signal can be exported in several common formats, including:

• PRONTO
• Global Caché (compressed or uncompressed & all devices)
• Command Fusion
• IRLib
• IRremote
• LIRC RAW
• RAW
• ‘C’ code for both IRLib & IRremote on Arduino

To get the signals on to his smart phone, he opted to use the Global Caché format, which is easily exported by AnalysIR. Another option with this app would be to use PRONTO format which is also supported by AnalysIR. For his next project, Sertunc plans to delve deeper into the bit patterns of the AC IR signal to reverse engineer the bit patterns of the individual fields & checksum. Stay tuned….

The ‘Samsung IR – Universal Remote‘ app is supported on extensive range of smart devices, including:  Galaxy S4 , S4 mini , Active , Zoom, S5 , S5 mini , MEGA, Note 3, Note 8.0 , 10.1, Galaxy Tab 7.0 , 7.7 plus, Tab 2 7.0 I705, 10.1, Tab 3 8.0 , 10.1 P5220 , P5200
Tab Pro 8.4 , 10.1 , 12.2 and others with IR transmitter. It looks like the Author will add more devices on request, provided it has an IR transmitter.

So what does the signal look like? Below is a screenshot showing 2 of the captured images.

Chigo Air Conditioner Infrared Signals AnalysIR Screenshot (click for larger image)

Finally, here are some links to the Chigo AC Infrared signals in various formats:

IRLib format – automatically generated ‘C’ code
AnalysIR Session History file – for import into AnalysIR (AnlaysIR users only)

You can get your own copy of AnalysIR – here.

For referency the Chigo Aircon unit is a  wall type 9000 btu unit id CS-25H3A-V118AY1

The IR codes are reported to be the same for following Chigo models: CS-35H3A-M118AH4, CS-51H3A-P118AH4A, CS-61H3A-P118AE2, CS-70H3A-W118ASA

Although this article relates to the signals of the Chigo AC unit, Sertunc points out that the same process can be applied to any brand of Airconditioner (Samsung, Daikin, Mitsubishi, Protec, Ilia, Panasonic, Sharp, Sanyo, Toshiba, Carrier, LG etc) which can be controlled by Infrared.