How to connect outbuilding

[champson]

Hi Adam,
I have my OHS running for a while now as you know, and it's really a fantastic system.  Currently I only have it running in my outbuilding, and don't have it in my main house.   The outbuilding is connected via fibre cable to the main house, so both locations are on the same ethernet network.   I have been wondering how to expand my alarm system to include the main house,  and if it is possible to use some kind of expansion system connected over ethernet?   I don't really want to have another complete gateway, but perhaps that is my only option.

Cheers,
Charlie.

[vysocan]

Hello Charlie,

thanks for the compliment. I must say the STM32 is pretty solid microcontroler, and I'm happy with it as well.

For the expansion, I have in fabrication new boards, they have 8 balanced zones and a relay. I've just recently posted on blog: https://openhomesecurity.blogspot.com/2020/12/expansion-board.html
These have possibility to expand the main board over wire RS485 or over radio RFM69. But not Ethernet. If you had an extra Cat 5  wire instead of fiber, then it would be a nice choice as RS485 works perfectly over a pair of Ethernet wire and 1 wire ground. There exists for sure an RS485 to Ethernet adapter, but what I know they usually work 8 bit. Gateway use a bit special 9 bit protocol, where the 9bit is wakes up the receiver. And a pair of them may be more expensive then a new gateway.
If it's not far, then you may try to connect them over radio. It works 200m in open environment, can penetrate walls and even concrete. But obstacles weaken the signal. I've bought a better antenna for my gateway and my garden sprinkler node that is buried in ground to achieve uninterrupted connection. Rest of my nodes work with a rubber or wire antennas. There are many options of such antennas connected to pigtails, even with long cables and mounted outdoors.

Adam

[champson]

Hi Adam,
That looks great.  I think I will run some cat5 between the buildings, I have a conduit buried underground with some string in, as well as the fibre.  Is the expansion board able to be powered, along with the extra zones, with just the RS485 connected from the main board?

[vysocan]

Hello,

The board will need its own 12V power. Just ground wire should be connected from gateway RS485 port and twisted pair for A/B. The X on PCB is for 12V wire, but not connected internally.

Also I will have to first create the code for it, and test it. Already thinking about it, and how to reduce the traffic. Since the zones are scanned 4 times a second multiply by 9 zones, that is with headers 42bytes, then gateway ack 5 bytes. I'm bit worried about the traffic on the 19200 bit per second RS485 line. Or actually not about the traffic, but the congestion for other nodes. This will show how good I've implemented Carrier Sense Multiple Access  I've done some test previously, but this will be rather continuous data flow.

[vysocan]

Hello Charles,

If you are interested I have the board ready. https://openhomesecurity.blogspot.com/2021/02/zone-expansion-board.html

I've tested it for a while, I hope it should be fine. So far I have prepared program only for RS485. Board is NOT sending OK for balanced inputs, and gateway switch them back to OK state automatically. This should reduce the traffic.

Adam

[champson]

Hi Adam,

That is great news,  I will order one along with some other bits.    Next step for me is to look further into the MQTT functionality, otherwise it’s all working very well.

Cheers,

Charlie.

On 7 Feb 2021, at 09:28, vysocan [via OHS] <[hidden email]> wrote:

Hello Charles,

If you are interested I have the board ready. https://openhomesecurity.blogspot.com/2021/02/zone-expansion-board.html

I've tested it for a while, I hope it should be fine. So far I have prepared program only for RS485. Board is NOT sending OK for balanced inputs, and gateway switch them back to OK state automatically. This should reduce the traffic.

Adam

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NAML

[vysocan]

Hello,
The MQTT is currently misbehaving a bit. After some days it start to cycle connected / disconnected. But I'm looking into it already.
But in general there are all groups, zones, and sensors. So you can do some logging, build some MQTT panel in mobile or computer, or do other automation like Home Assistant.
Adam

[vysocan]

Hello Charles,

have you progressed with the expansion board somehow?

I've been doing more work on the software side, and found some small issues. One was related to alarm monitoring of "not set" group. That is, there is a missing check for valid group number in alarm thread, causing a false alarm for this "not set" group. Preparing a new firmware.

[champson]

Hi Adam
Thank you for the information.  I haven’t managed to get the cable installed between my house and garage yet, but might just set up on my workbench first to see how it works.  Is the new firmware for the main gateway or the expansion board?
Best regards 
Charlie 

On 19 Mar 2021, 05:50 +0000, vysocan [via OHS] <[hidden email]>, wrote:

Hello Charles,

have you progressed with the expansion board somehow?

I've been doing more work on the software side, and found some small issues. One was related to alarm monitoring of "not set" group. That is, there is a missing check for valid group number in alarm thread, causing a false alarm for this "not set" group. Preparing a new firmware.

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NAML

[vysocan]

Hi,

just the gateway.

[champson]

OK Great, I will let you know how I get on.  The rest of the system continues to run great.  

Cheers,

Charlie.

On 22 Mar 2021, at 13:04, vysocan [via OHS] <[hidden email]> wrote:

Hi,

just the gateway.

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NAML

[vysocan]

Nice to hear.
And, one more thing, maybe you would be interested in this enhancement https://openhomesecurity.blogspot.com/2021/03/authentication-node-changes.html. Not sure if you read my blog
If so, you would need USBasp programmer to flash new sketch.
It is not necessary though.