Make a "clean contact" by changing a Sonoff Basic or RF (R2)

4 minutes of reading
PURPOSES OF PROJET:
  • Make a clean contact through a Sonoff Basic (R2). The R1 guide is available here. The guide is also suitable for Sonoff RF (R2)
  • Difficulty level: medium
  • Cost: <10 € (cost of the unit to be modified)
CONCEPTS FACED:
  • Modification to electrical scheme
SOFTWARE COMPONENTS USED:
PHYSICAL DEVICES USED:
PROJET MOST INDICATED FOR:

All environments

Notes and disclaimer
  • qualsiasi eventuale modifica agli impianti domestici dev'essere progettata ed realizzata SOLO 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: 1.1

ATTENTION: this guide refers to second version di Sonoff Basic (R2).
The guide on before version is available here.

An alternative to the change explained in this projet is the Sonoff 4ch PRO, which has four factory clean contacts without needing any modification, or the Sonoff Mini, always to be modified, but more compact than Sonoff Basic.

Abstract

A simple wall switch, to understand, is a device that, in a mechanical way, puts two poles in "contact".
The amount of current flowing through the circuit at the end is indifferent to him (except in the case of too much, but only for physical reasons that would lead him to break): it simply limits itself to open / close that segment of the circuit.

TheITEAD Sonoff Basic is a home automation actuator that, by default, is designed to have 230v in and out 0v or 230v outgoing, based on the state of excitation of its relay, or based on the fact whether it is "off" or "on".

Well, this device can be made a physical change able to make the two output poles similar to those of a mechanical switch: it would therefore become a "clean contact", in the sense that the activation of its relay would bring the two poles to close between them rather than pass the voltage to 230v. At the input, the device will still keep the 230v (useful to power its circuitry in order to control it), but no it will deliver more output voltage, thus limiting itself to “to close"The two poles of the output.
The equivalent of a mechanical switch, though intelligent.

Let's imagine, for example, that we have a boiler for independent domestic heating activated through a traditional thermostat that for activation uses, for theappanointed, a clean contact. Replace the traditional thermostat which will allow it to be Sonoff Basic modified to clean contact allow to domotize domestic heating, because by activating the actuator we will close the two activation contacts of the control unit and vice versa.

Not only: another area of ​​use, important in personal home automation, that's it of remote control home automation rolling code.

To whom would you like appromerge the concept of "clean contact" and its use in personal home automation, we recommend reading di this article.

Prosubsidence

Before starting, we remember that:

Notes and disclaimer
  • qualsiasi eventuale modifica agli impianti domestici dev'essere progettata ed realizzata SOLO 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.

Guys caution. Safety first.


Il Sonoff Basic (R2) is presented, inside, as follows:

Sonoff Basic - RF R2 POWER - Front
frontal image of the R2 board

While on the back:

Sonoff Basic - RF R2 POWER V1.0 - Back
image of the back of the board R2

Il proyield involves:

  • unsolder two contacts (with the help of a soldering iron and a desoldering pump) and interrupt the bridge between the two contacts
  • unsolder an N (neutral) contact and resolder it on a new point on the board.

Desolder and stop the bridge

The contacts to unsolder are those, on the back of the board, indicated as follows:

Sonoff Basic RF R2 POWER V1.0 - Back - Desoldered contacts for clean contact

After dissolved and removed the surface tin, it is necessary to carry out a cutting physical using mini precision drill using a small millstone:

Sonoff Basic RF R2 POWER V1.0 - Back - Contact cut

The cut must be net e profondo.

Sonoff Basic RF R2 POWER V1.0 - Back - Contact cut made

At the end of the cut, check carefully - through the multimeter - that there is no more no interconnection between the two contacts.

Reposition contact N (neutral)

At this point, again using a soldering iron and a desoldering pump, it is necessary unsolder contact N (neutral) shown in the figure:

Sonoff Basic RF R2 POWER V1.0 - Contact N

for resolder then the cable on the "1 Contact" previously unsoldered:

Sonoff Basic RF R2 POWER V1.0 - Contact N - new position

First di prosee the restnamecontact N is required dig a small notch on the proside edge of the board (always using the precision drill) to make it possible to pass (and the subsequent restnameof the board inside its white plastic shell):

Sonoff Basic RF R2 POWER V1.0 - Contact N - notch of prowire

At this point the change to "clean contact": will be completed:

Sonoff Basic RF R2 POWER V1.0 - Modify clean contact terminated

Verifica

Now to verify that the modification has been carried out correctly will be sufficient to measure using a multimeter that the potential difference on the output poles of Sonoff (with relay obviously activated!) is equal to 0 volt.

There must be no output voltage, in a clean contact. If you measure 230v (or any other value other than 0), change it it will not have been carried out properly.

utilization

Followed the proindicated you will finally have a Sonoff Basic modified to "clean contact".
As explained the uses are the most disparate.

A shining example is related to the use of this modified component as an actuator for domotizing an independent heating system. Another example that we report comes from this article from theinstructables.com in which a user has modified to clean contact, has updated the device to firmware Sonoff Tasmota and he assembled, in his own way, a home automation gate opener.

Another scope of use, important in personal home automation, that's it of remote control home automation rolling code.

Very comfortable, in havenamento this change, comes the PULSETIME firmware command Sonoff-Tasmota, which allows us to transform the Sonoff Basic modified to a smart button. Actually the adoption of the firmware Sonoff-Tasmota is not a must (as much as advocated): it is sufficient, in fact, to use the "inching" mode of theapp eWeLink usually used when the actuator firmware is the original one.

Video-demonstration

The inDomus community thanks very much badalex for his crucial support in drawing up this guide.


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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