Interfacing with panasonic heat pump via serial connection

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kiwijunglist

2981 posts

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#242369 24-Oct-2018 21:11

Been doing a lot of home automation stuff around the house.

Currently my heat pump uses the following to interact with my home hub.

Broadlink RM Mini3 IR Blaster

Xiaomi door sensor - to sense whether the heat pump is on or off (via the vent opening)

Home automation via home assistant integrating the above with some automations to check the heat pump received the on / off signal and resend if it fails etc.

I know a few people are interfacing the mitsi heat pumps via a serial interface and a pi or esp8266 or similar. Is anyone doing this with a panasonic heat pump. I'd much prefer to control it via the serial interface.

HTPC / Home automation (home assistant) enthusiast.

datahawk

251 posts

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#2113533 24-Oct-2018 22:38

Interesting - Does your Panasonic Heat Pump have a standard RS232 serial port with a published command API?

I have a Panasonic 3D Projector which has a rear RS232 port and the commands are published in the operators manual.

I recently built myself an ESP8266 Wifi controllable RS232 port where the projector is now controlled by Wifi http commands that are converted into true RS232 commands.

Building the circuit board and writing the code for a Wifi controllable RS232 port is not quick job but can be done quite cheaply if you have the skills.

phrozenpenguin

840 posts

Ultimate Geek

#2113554 24-Oct-2018 23:46

datahawk:

Interesting - Does your Panasonic Heat Pump have a standard RS232 serial port with a published command API?

I have a Panasonic 3D Projector which has a rear RS232 port and the commands are published in the operators manual.

I recently built myself an ESP8266 Wifi controllable RS232 port where the projector is now controlled by Wifi http commands that are converted into true RS232 commands.

Building the circuit board and writing the code for a Wifi controllable RS232 port is not quick job but can be done quite cheaply if you have the skills.

Not wanting to take this off topic but wondering if you used any specific packages or firmware on your ESP8266 for your wifi > RS232? Or coded from scratch?

To the original post - I don't know for Panasonic but for Daikin I bought an additional Daikin box which connected internally to S21 (serial?) and gives wifi control. Their app is a bit naff but can be used over http - and works with Home Assistant.

premiumtouring

355 posts

Ultimate Geek

#2113565 25-Oct-2018 06:24

I also have a couple of Panasonic heat pumps and was awaiting the Broadlink to arrive so that I could start communicating with them via Home Assistant. Interesting to hear the measures you have to take to check its status etc. Keen to hear if anyone else has had success with controlling or interfacing with Panasonic Heatpumps. Happy to chip in/sponsor a portion of the coding venture if someone has the skills or know how to build something like this.

datahawk

251 posts

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Lifetime subscriber

#2113645 25-Oct-2018 10:19

phrozenpenguin:

Not wanting to take this off topic but wondering if you used any specific packages or firmware on your ESP8266 for your wifi > RS232? Or coded from scratch?

I build a lot of ESP8266 devices and prefer to write all of my code, mostly Arduino based, for them where possible.

The code required for the ESP8266 Wifi-RS232 devices took a while to perfect with a lot of trial and error but I now have several of these Wifi-RS232 ports driving RS232 SMS Modems 24/7 in my office.

(I built these units to do away with having to use serial cables connected to a specific computer to control modems. Now most RS232 serial devices can be controlled by any server or workstation on the network just by sending http commands to their specific IP addresses.)

Regarding this topic - I am interested to know if anyone's heat pumps, (Panasonic, Mitsubishi or other) have serial ports hidden away and if anyone has a published specification of the commands?

I have 5 x Mitsubishi units (A large 4-Split unit and another single unit) that do have some sort of serial connector somewhere but I have yet to find any specification of how these operate. These pumps are all currently controlled with IR signals and some are again driven with custom built Wifi ESP8266 IR Sender units.

premiumtouring

355 posts

Ultimate Geek

#2113649 25-Oct-2018 10:24

I will definitely have a look when I get home. I'm very curious to know if there is a service port.

I'd be keen to use one of my Particle Photons for this as they're tiny and would be perfect.

kiwijunglist

2981 posts

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#2113653 25-Oct-2018 10:28

Regarding serial control and mitsibishi.

https://nicegear.nz/blog/hacking-a-mitsubishi-heat-pump-air-conditioner/

And Google cn105 heat pump for some more results.

Not much information on Panasonic.

HTPC / Home automation (home assistant) enthusiast.

datahawk

251 posts

Ultimate Geek

Lifetime subscriber

#2113657 25-Oct-2018 10:33

kiwijunglist: Regarding serial control and mitsibishi.

https://nicegear.nz/blog/hacking-a-mitsubishi-heat-pump-air-conditioner/

And Google cn105 heat pump for some more results.

Not much information on Panasonic.

Nice Find! - I'll be investigating those interfaces - Thanks.

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kiwijunglist

2981 posts

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#2113672 25-Oct-2018 10:38

Your WiFi serial interface sounds good.

Might be able to have someone hack/probe my Panasonic heat pump remotely as it's probably beyond my ability

HTPC / Home automation (home assistant) enthusiast.

datahawk

251 posts

Ultimate Geek

Lifetime subscriber

#2113750 25-Oct-2018 12:11

kiwijunglist: Your WiFi serial interface sounds good.

Might be able to have someone hack/probe my Panasonic heat pump remotely as it's probably beyond my ability

You could be lucky with your Panasonic A/C if it's a relatively recent model. Finding the interface connection and command specs will be the main problem.

Sadly, after some study (thanks to your very useful links), all of my Mitsubishi units are MSZ-FA 2006 models and they don't have the CN105 serial interface connector on board so I'm stuck with IR control only.

However, IR is not an issue because they have been automated that way for many years already with custom built temperature sensors integrated into my home/office automation systems that start, stop and set A/C units as required with 'learned' IR command strings.

It would have been nice to get settings feed back from a serial port.

(I run a Linux server 24/7 which is the central controller for most of my sensors and office/home/workshop automated systems.)

Best of luck with your quest.

Edit: Typos

wombat1188

2 posts

Wannabe Geek

#2215867 12-Apr-2019 16:38

Hey guys, first post. I've just installed a second hand Panasonic heat pump (CS-E24PKR) and am really keen to get some automated control over it. I got a quote for the Intensis wifi module that plugs into the CNT-CN connector on the main board of the indoor unit, $420!!! I made up a plug for the CNT-CN connector which can be located/accessed with help from the service manual (details here, I purchased this and this) and I've hooked it up to a scope borrowed from work but I see no UART comms at all, presumably you have to first send the magic string as this page shows (for a different model). Tried sending the string from that page but no luck.

Anyhow, I'm really hoping to get some details of the comms protocol so I can whip up a wifi controller using ESP chip which I would obviously make available to anyone who wanted to replicate it. I don't suppose anyone has an Intensis unit that they'd be willing to lend for a week so I can sniff the data? Compatible units are:

• PA-AC-BAC-1
• PA-AC-ENO-1i
• PA-AC-ENO-1iC
• PA-AC-KNX-1i
• PA-AC-MBS-1 (this one is ModBus)
• PA-AC-WMP-1 (this one is WiFi)

Cheers

wombat1188

2 posts

Wannabe Geek

#2215869 12-Apr-2019 16:42

Wow bit of a link fail there.

UART info and magic packet for different model

Pre-crimped cables for connector

Plug for connector

Service manual

ashtonaut

614 posts

Ultimate Geek

#2582063 9-Oct-2020 19:39

Has there been any progress made by anyone in this thread in the past 12 months?

I’ve also got a couple of Panasonic heat pumps, both currently controlled by Broadlink RM units, but I’d love to be able to get two-way comms working via something plugged into the serial port that’s not as expensive as the Panasonic CZ-TACG1.

Cheers

andrewbnz

59 posts

Master Geek

#2583360 12-Oct-2020 22:10

I was looking into this about a year ago but ran out of time to follow through with anything.

However when I was looking into this I came across some guys that had managed to decode the serial protocol for Panasonic H & J series Air/water heat pumps and have developed software and hardware for connecting to the Panasonic Heatpumps CN-CNT connector using ESP8266 devices. See https://github.com/Egyras/HeishaMon They also have a slack channel and are very helpful around the decoding side of things.

Unfortunately the H & J Series units appear to use different protocols so their research did not work for me. However as I already had a CZ-TACG1 I was able to snoop on the serial packets sent between the CZ-TACG1 and the heat pump unit and have some of the raw commands used to control the heatpump. Unfortunately since then my available time to work on this has been non existent.

But i'm happy to share what I have got if anyone is interested,

stibbzy

1 post

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Inactive user

#2601745 11-Nov-2020 13:05

Hi @andrewbnz

I have a CZ-TACG1 as well, and would love a solution that get's it out of the cloud. Did you have any luck controlling it with your snooped commands? I'd be interesting in knowing any details.

Cheers,

andrewbnz

59 posts

Master Geek

#2603049 12-Nov-2020 22:25

stibbzy:

Hi @andrewbnz

I have a CZ-TACG1 as well, and would love a solution that get's it out of the cloud. Did you have any luck controlling it with your snooped commands? I'd be interesting in knowing any details.

Cheers,

Unfortunately I have not had any further time to do anything more on this. I have what i was able to decode haven't done anything further than that.