{"id":1761,"date":"2025-04-01T13:00:00","date_gmt":"2025-04-01T11:00:00","guid":{"rendered":"https:\/\/www.domedia.net\/?p=1761"},"modified":"2025-06-07T11:26:21","modified_gmt":"2025-06-07T09:26:21","slug":"use-case-freeing-a-fully-locked-home-automation-system","status":"publish","type":"post","link":"https:\/\/www.domedia.net\/?p=1761&lang=en","title":{"rendered":"Use case: Freeing a fully locked home-automation system"},"content":{"rendered":"\r\n
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\"CANBus<\/figure>\r\n\r\n\r\n\r\n

One of our customer has offered a challenge. The mission was to succeed to connect a fully open-source home automation system: Home-Assistant<\/a> with a fully closed and proprietary system. Goal was to get an intuitive system, easily customisable by customer, and way more evoluary without constraints, and without changing all hardware installed. At end of article, you’ll know how to interface easily with CANBus<\/a> home-automation system installed by Spline<\/a> \/ Innoxel<\/a> using Home-Assistant to take control over whole system.<\/p>\r\n<\/div>\r\n\r\n\r\n\r\n

I’ll start to present existing and informations we could collect, then I’ll go into the practical steps to discover the protocol and be able to mimic it with Home-Assistant and final result.<\/p>\r\n\r\n\r\n\r\n

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Existing system, installed around 10 years ago, is quite cumbersome and also not really common in home-automation. It’s based on AMX<\/a> platform with NI-2100 controller that controls a CAN gateway.<\/p>\r\n\r\n\r\n\r\n

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CAN is a fieldbus at slow speed on one or two wires, very much used in cars and in industrial applications, quite similar in concept with KNX. It has been developped by Bosch in the 80’s.<\/strong><\/p>\r\n<\/blockquote>\r\n\r\n\r\n\r\n

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\"CAN<\/figure>\r\n
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All inputs\/outputs in the system are on the CANBus, which is very original for home-automation. According at our investigations, software part of the system is probably using a generic code loaded in the AMX\u00a0controller, and a customised part done through a proprietary software (Smart-Control<\/a>) from Spline<\/a> company. Luckily, customer got copy of the programming software and project files. We have been able to discover that it works in a very similar way at KNX with a collection of inputs interfaces (dry contacts of wal buttons, radars, temperature sensors) and outputs (lights dimming, shades control, relays for heating system. Each module is physically numbered in electrical panel and also in program, so it should be easy to find connection between both.<\/p>\r\n\r\n\r\n\r\n

After some investigations on Internet, we have found out that interfaces are manufactured by a swiss company Innoxel<\/a> and use a non-documented protocol Noxnet. We’ll have to listen message on CANBus to try to decode it and understand the protocol.<\/p>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n\r\n

\"Modules\r\n
CAN Modules<\/figcaption>\r\n<\/figure>\r\n\r\n\r\n\r\n
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\"ESP-CAN<\/figure>\r\n
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To do that, we are going to use ESPHome<\/a> that supports CAN natively, using a standard CAN interface based on TJA1050, that is the most used chip for CAN interface. Simple assembly like on picture on left (ESP32-C3 de SeeedStudio<\/a> and CAN interface<\/a>) and little piece of ESPHome code should be all we need to listen what happens on the bus. Warning CAN\u00a0is supported only on ESP32, not ESP8266 neither 8285.<\/p>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n\r\n

canbus:\r\n\u00a0 - platform: esp32_can\r\n\u00a0 \u00a0 tx_pin: GPIO3\r\n\u00a0 \u00a0 rx_pin: GPIO33\r\n\u00a0 \u00a0 can_id: 4\r\n\u00a0 \u00a0 bit_rate: 100kbps\r\n\u00a0 \u00a0 use_extended_id: false\r\n\u00a0 \u00a0 on_frame: \u00a0 \r\n\u00a0 \u00a0 - can_id: 0x000\r\n\u00a0 \u00a0 \u00a0 can_id_mask: 0x000\r\n\u00a0 \u00a0 \u00a0 then:\r\n\u00a0 \u00a0 \u00a0 - lambda: |-\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 std::string b(x.begin(), x.end());\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 ESP_LOGD(\"can id 0x42B \", \"%s\", &b[0] );<\/code><\/pre>\r\n\r\n\r\n\r\n
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4 keypoints regarding ESPHome sketch:<\/strong><\/p>\r\n\r\n\r\n\r\n