Domotise any remote control (even rolling code) by a clean contact

6 minutes of reading
PURPOSES OF PROJET:
  • Control an infrared and / or radio frequency remote control (including rolling code) via the profirst personal home automation
  • Difficulty level: medium
  • Cost: bass
CONCEPTS FACED:
  • functional logicnameof the remote controls
  • hardware modification
  • software configuration
SOFTWARE COMPONENTS USED:
PHYSICAL DEVICES USED:
  • a remote control already proprogrammed for its function (eg gate opening, alarm activation, etc.)
  • a home automation actuator with clean contact (explained later)
  • a small welder
GUIDE MOST INDICATED FOR:

All environments

Notes and disclaimer
  • qualsiasi modifica all'impianto elettrico dev'essere progettata ed effettuata da personale qualificato;
  • any changes implemented in probefore is a propersonal responsibility as well as a profirst risk and danger (the contents of the present page are purely educational);
  • any changes implemented in proprior to a device it voids the guarantee, quality approvals and certifications.
revision projet: 2.0

Abstract

Check the functions of a remote control via home automation, be it infrared or radio frequency, it is one of the keys to succeeding in domotize the non-domotic.

We spent on inDomus far and wide in describing devices such as the Broadlink RM Mini 4 or the elder brother, theRM Pro+, as examples of devices capable both of connecting to Wi-Fi (and therefore to our home automation) is to transmit / receive infrared signals. It's easy with devices like this acquire these codes from the original remote controls of the devices to be domotized, then enter these codes in the home automation configuration and be able to control the devices.

Examples related to this winning approare some our projets, among which we recall:

and many others.

Il proproblem, unfortunately, arises when some remote controls, for different reasons, they cannot be "copied" through the aforementioned devices within our personal domotics.

Although most of the canvases and radio controls are easily reproducibili in domotica through the techniques mentioned above, some rappresent an insurmountable rock by their very nature. Some, in fact (especially those related to the opening of gates, not to mention those dedicated to alarms), for security reasons use variable codes (called rolling codes) which appgreasy vary with each transmission. In practice the procedura of appyield of remote control codes it becomes vain, because the codes received (which should then be entered in the home automation configuration) are no longer valid a moment after having detected them.

Other remote controls, on the other hand, use fixed codes but simply use infrared or radio signals products respectively with "non standard" wavelengths and frequencies, therefore the "bridge" devices such as the aforementioned Broadlink they are not able to receive and interpret you, making it impossible to domotize with the technique mentioned above.

AND THEREFORE?

A solution exists however.
If the only device capable of sending a given signal (IR or radio) is - for the reasons mentioned above - the remote control itself, well, we will physically domotize the remote control itself.

Anatomy of a remote control

A remote control is essentially composed of:

  • a power source (typically, a battery);
  • a control electronics;
  • an emitter (infrared or radio);
  • one or more buttons.

The buttons usually they act mechanically on pairs of contacts which, when pressed, are briefly connected. That connection springs up in the activation of electronics which, based on the pair of contacts, emits the signal foreseen in the technical modes provided by the emitter.

Let's see how it is made, in broad terms the inside of a remote control:

Radio remote control extension

How to domotize the remote control

The above scheme suggests that if hypothetically we connected two wires to the two contacts of a given button and, subsequently, we put them in contact through the use (for example) of a mechanical switch, we would trigger the signal transmission:

Remote control with switch

At this point, to make a remote control domotic, any remote control, it will be enough appuse an actuator instead of the manual switch of the example above and therefore able to trigger the transmission of the signal (and the actions that follow from it) that we need. Obviously, in the presence of more buttons / functions they will be placed as many actuators.

But what technical features must this actuator have?

  • It must provide functionality of "clean contact", Or to its activation must for theappoperate similarly to a switch that connects two contacts;
  • it must be easily integrated in home automation;
  • must be able - when activated - to close the contact for a set time.

This last feature is easily explained: an actuator, when activated in this scenario, must not maintain the "closed" status on the two contacts on which it is attested, but for a limited period of time (typically below the second). This is because it will have to simulate the pressure of a button, which appgrease is usually performed for very short moments.

Choose the actuator

The choice regarding the actuators to be implemented it's wide. We will make one congenial to us because it is already known and "comfortable" enough: the use of a simple one Sonoff Basic modified to "clean contact" or a Sonoff Mini (always modified). A good alternative, if the necessary channels are two, is the Sonoff dual, too modified to "clean contact".

Although many other solutions exist (for example the form “ITEAD 1 Channel Switch"), The advantage in using a Sonoff Basic modified lies in the fact that it already has the 230V AC power supply circuit (the above mentioned module, for example, also needs a power supply), is very cheap, small, functional, and above all supports the firmware Sonoff-Tasmota, which allows to implement an inching control (that is the auto-shutdown timing) extremely accurate, to the tenth of a second, as well as the proProtocol MQTT, which allows easy integration with our loved ones HUB personal.

In case more than one actuator is needed, a smart choice can also be that Sonoff dual (to modify) or del Sonoff 4CH Pro, who, without needing any physical modification, offers of factory four clean contacts manageable in home automation.

Regardless of what the choice is actuator to implement, the scheme will be similar to the following:

modified remote control with clean home automation contact

Make the change

We said they will go attested as many "wires" as there will be buttons (and therefore the pairs of contacts) to be checked esternameMarketplace and, subsequently, as many actuators from applicarvi.

To carry out this activity and before any physical modification - and even before dismantling the remote control - care is taken of appurare that all the buttons that interest us are actually working for the functions that interest us. Especially in the case of rolling code remote controls, it is not uncommon for there to be prospecific procedures to carry out the programmation of the buttons and functions: for this purpose, refer to the specific system documentation that is to be domotized by physically modifying the remote control.

Given that it is of a physical change, could later be difficultproadjust the functions of the remote control.

Carry out all the necessary checks, disassemble the remote control and, acquiring holy patience, a child welder, wires and tin, provvedere welding of the various pairs of wires on the contacts of the buttons that we expect to domotize as from projet.

After the change

CON SONOFF BASIC MODIFIED

If you have chosen to use (as illustrated above) a Sonoff Basic (modifying it) the to-do list will be the following:

CON SONOFF 4CH PRO R2

If you have chosen to use (as illustrated above) a Sonoff 4CH Pro R2, the to-do list will be as follows:

OTHER TYPE OF ACTUATOR

At this point, assuming you were able to power your actuator and connect it as a clean contact to the remote control contacts, all you have to do is check it, then:

  • configure the actuator (s) at the proprio personale HUB as MQTT switches (integration is relative to the choice made).

Nb The aforementioned idea to configure the actuators at the proprio HUB as simple MQTT switches is not the preferable choice. This is because doing so the rapplogical resentation of what we are going to domotize at thepersonal HUBis not correct: if I check the opening / closing of tapparelle, a gate, an alarm or anything else I don't expect to have to use, on my own HUB, the simple ones switches, but rather a true entity e proman that rappwith all the functions of the domotized element.

Example: in the case of domotization of a gate remote control, configuring the actuators as simple MQTT switches I would equip myself with appgrease of two on / off switches which, respectively, control opening and closing. Much more correct it would configure a single entity "lock"Which, when selected"open"Open controls, vice versa closing.

To do this you can easily use Node-RED. We have dedicated to this an extended projet.

Use

If you have done everything right and regardless of the type of final management tools that you will use, when activating the actuator (or actuators), the component prowill be able to close the contact clean for the period of time chosen by you and the remote control will activate, performing what it was programmato to do.

At this point the limit is the imagination: when the element is domotized and is rappresented by aentity working in home automation, you can do whatever you want (check it out, automate it, etc.).


Domotize a traditional alarm system with MQTT e Node-RED (part 1)


ITEAD Sonoff BasicATTENZIONE: remember that there is on our FORUM community an ad hoc section dedicated to Sonoff (and more generally to devices ESP8266), for any doubt, question, information on the specific merit of these components.


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