Reverse engineering climate comtrol - Page 1
Forum section: electronics / beginners

author: pjhsv
author_rank: Newbie
timestamp: June 26, 2019, 12:26:50 pm
content: I have a Bonaire heating/cooling system at my house. Controller is a ct10mc04 panel (power, mode, up, down buttons). Is it possible to use a scope or logic analyser to work out what each button is doing,so I can replicate that with an arduino?I'm not really sure where to even start with connecting it up. Do these normally run some sort of general protocol or language, or is everything usually custom proprietary, and harder to work with? Are there any online resources for this sort of stuff?

author: noidea
author_rank: Unknown
timestamp: June 26, 2019, 02:27:30 pm
content: The short answer most named brand AC control systems on the market in Oz are proprietary, so monitoring it then brute force is probably the best way to achieve your end result.Some other hintsUse the actual model number of the air conditioner / heater in your search queries may lead to better results.A quick google of that model number brought up thishttps://www.ebay.com.au/itm/Bonaire-PNE-Wall-Mounted-Manual-Thermostat-Controller-CT10MC04-/133070538047?nma=true&si=%252BMSkaZmuKmyaxJDaagTwAC5HEZE%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557Which led to PNE as the OEM, maybe you could try them but they probably have some sort of NDA with Bonaire, or alternately even speak to Boanire and see if they have any sort of automation interfaces availablehttp://www.pne.com.au/index.shtmlI would suggest trying the Whirlpool site and the aircon section there as it seems to attract tech/IT minded people and I have seen a couple of posts on doing similar with other AC brandshttps://forums.whirlpool.net.au/forum/138?g=222

author: pjhsv
author_rank: Newbie
timestamp: June 28, 2019, 01:19:06 pm
content: Thanks.I contacted PNE & Bonaire.Interestingly, one of the Bonaire distributors replied with"No our controllers don’t adapt to home Automation system YET"Sounds like there might be something on the horizon

author: magic
author_rank: Super Contributor
timestamp: June 28, 2019, 09:19:31 pm
content: I know somebody who automated such a proprietary system by simulating appropriate button clicks with relays.Optocouplers would likely be OK too or even better.

author: pjhsv
author_rank: Newbie
timestamp: June 29, 2019, 10:26:47 am
content: That's a great idea. And simple too!

author: tpowell1830
author_rank: Frequent Contributor
timestamp: June 29, 2019, 12:09:44 pm
content: One of the dangers of using a high speed mcu to control a low speed system is to switch things too quickly. Motors and solenoids are not designed to switch on and off too quickly, especially pump motors (for freon). The motor is loaded down under pressure and the pressure must equalize for a period of time before the pump switches back on or you will burn out the motor. This is also true with solenoids because there is a switching limit before these overheat.You need to study the mechanical portion of a system such as an aircon, before applying a homemade system control design. There is a certain mechanical hysteresis required and you should study the factory designed system to determine this. An mcu is overkill for such a system, but setup correctly, it can be done. Consider the cycle times required before writing software.Just my 2 cents...

author: pjhsv
author_rank: Newbie
timestamp: June 29, 2019, 02:14:08 pm
content: Thanks for the tip - appreciate it.Wouldn't just using transistors to bridge the controller buttons solve that issue by the nature of the controller itself still incorporating the required time restrictions? All I'm really doing is electronically pressing the buttons that are on the front of the panel.