In January 2005, I bought a new Climatouch thermostat, and I just couldn't wait to figure out how it works. Most intriguing is a 5 pin connector on the back that is readily accessible. Being an engineer with a few decades of embedded product development experience, I believe that this connector will prove to be a serial interface. At the least, the connector is used in the factory to program the microcontroller in the thermostat. More likely, it is used by the the manufacturer (AED) for development and debugging. If this is the case, there is great potential to integrate the thermostat with a home automation system. I have contacted the manufacturer and they insist that the port is for manufacturing only. There are a few other interesting possible opportunities on the main board. I hope that this page can provide a jumping off point for other people to investigate this product further.

These pictures were taken with a Kodak DCS560 digital camera and a Canon EOS series lens 28-105mm/f3.5-4.5, with the help of a large magnifying lens (which causes the barrel distortion and chromatic aberrations.

The Climatouch Model CT03TS thermostat.	The back of the thermostat. There are 4 screws that secure the back. The mystery connector is circled.	The component side of the logic board - a.k.a. "the guts".	The guts will drop out of the rest of the housing, and LCD flips out.

The reverse side of both the logic board and LCD.	The LCD back in place, and a mystery "reset" button circled in red. This button is not accessible with the housing on.	Close up of component side of the logic board. Note the missing relays and circuitry for the humidity control (Model CT03TSH).	Humidity circuitry on the left, touch sensor connector near the middle, mystery interface on thr right, with the outside sensor RF receiver behind it.

To disconnect the flat flex cables from the touch sensor & the LCD, push the black retainer away from the connector.	When the retainer is disengaged, the flex cable is released. Assemble in reverse order of disassembly.	On the back of the mainboard is a single white LED to backlight the LCD (blue circle). There appear to be 2 more positions for backlighting LEDs (red circles). I put a green LED on them and it lit up.	With the LCD flex cable out of the way, you can see the PIC18LF452 processor and 24LC128 serial EEPROM.

Another angle.	The CPU and two crystals, one for the CPU clock (upto 10 MHz) and the other, probably 32.768 KHz, for time keeping.	Clear view of the PIC18LF452 processor and 24LC128 16KB serial EEPROM.	The LCD is driven by a chip-on-board Samsung KS0723TB-01.

The PIC18LF452 is a neat little processor from Atmel with a maximum throughput of 10 MIPs, 32K bytes of Flash, 1.5K bytes of SRAM, and 256 bytes of EEPROM. It also has a 10-bit A/D converter, which is probably used for the touch screen. Also built into the chips is a full USART with the RX & TX on pins 1 & 44. If somebody could trace those pins back to the Mystery Connector, that would be great. If the USART is tied to the connector, the next step would be to look at this: "A FLASH Bootloader for PIC16 and PIC18 Devices".

Apparently the LCD driver is a new product, so I have not found any information on it KS0723TB.  However, I have found information on similar chips: KS0724, and KS0728, KS0708, KS0759, KS0741, and