WTH is this new Sonoff BASIC R2 V1.4 PCB?

Hi there. Can you confirm it works or do you guess it should? :slight_smile:
I would like to connect this layout to the 5v USB…

+5v and ground, I meant

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It should work, I am not sure

I just tried it, unfortunately, it does not work…

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oops, I was wrong then

Can you tell me what the numbers on the part marked “U2” are?

it is so tiny…but I think I read:
6211A (or 62114)
and bellow it: 1942/33

The 6211A is a low drop out voltage regulator but I’m having trouble finding a datasheet with that package to determine the pinout. From the other components nearby, at a guess it will be:

You can confirm this by looking at the negative marking on the capacitor on the other side of the board or by checking continuity to the marked GND pad at the bottom left of the board.

Hey guys,
I also got this new version board just yesterday (with single blue wire as shown) and need to use it as a dry circuit switch (ie no voltage output momentary switch for garage door operation) there are vids on how to mod the older 2 black wire version and the previous versions to that but nothing about this new version ?

So I was wondering if any of you guys can assist in how to convert this new board into a dry switch ?


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Bonjour jai le même soucis je souhaiterais transformer ce sonoff en contact sec je ne voudrais pas faire de bêtises jai une idée mais j’aimerais avoir des avis 16069205651065951357247252420712|666x500

Have you been able to do it? I´m having the same problem…
Any solution?

here it is how I proceed to have a dry contact.
First, for your safety all manupilations are to be done power off, socket unplugged.
Unsolder the blue wire.
then cut the track and the board as shown on picture. Be sure that the board is cut from the upper side to the downer side as the board is conducting on the both side. Check with a voltmeter the tension is missing then the resistance is infinite.
then solder a wire between the pin relay and the pin out.
Keep me advise.

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I got the dry contact working. All sonoff uses the 120v input to a transformer indicated in the picture. From there it gets an 5v output which it use to run the sonoff. I disconnected the wires from the transformer to pcp using a soldering iron, incase you want to back to the original state you just need to solder back the wire.

Now connect the 5v power source to positive and negative terminal as indicated in the picture. Now your relay will connect and disconnect the live terminals. There is no cutting of the board.

you just need to disconnect the transfomer lead on the other side. otherwise when you power up from the 5v, i believe it tries to convert that to 120v and draw lot of power with which the system will not work.

So, you simply disconnected the black and white wires from the transfromer to the pcb, and you welded these two wires to a 5v power source? I want to use this sonoff to connect my pc and turn it on or off, by connecting the sonoff to the motherboard, which has a 5v and Gnd. Do you think it’ll work by following your guide? Sorry im a newbie.

yes, will work, but you will have to allso make it dry contact , and use incing from the app menu, you can use it as a power on - power off contactor, or reset .

there is no need to cut any traces… just conect the two wires comming from you motherboard , one to input L, and the othe one to output L

polarlamb, trying to make my sonoff basic a dry contact. I understand what you said in the initial post but what does this mean?

you just need to disconnect the transfomer lead on the other side. otherwise when you power up from the 5v, i believe it tries to convert that to 120v and draw lot of power with which the system will not work.

Just wanted to say thanks for the info on converting to dry contact. I ordered 3x new Sonoff Basics and these type circuit boards arrived and I have it working.

I misunderstood at first and just removed the solder track at the bottom with a Dremel tool, and still had continuity. Like you said though, there is a track on the top side of the PCB too. I went a bit further with the Dremel and got through the top track too, i had to be very careful to not damage the relay itself (I didn’t remove it) but it worked ok.

Can Anyone advice me on how to flash this board.

I have 3 of them and tried a few different ways of flashing them without result.
The weird thing is that for example ESPeasy mentiones that the flashing went well,
But i cannot read the logging, and also it does not seem to connect to the WIFI.

I tried the way with the black button (GPIO0) and also the FTDI GND to Key wire.
Also the holding the black butting while programming it.

Nothing seems to work, and I have no way of checking, what went wrong.

This is the first board (and I had many) where this is so tough and also simply not working!).

Someone please advise?
Kinds regards,

Recently I also had problems with flashing. It looks like the latest boards need a bit more current than in the past. I had to switch to a CH340 based USB-to-serial adapter (set to 3.3 volt) to be able to flash my newest Sonoffs. In the past I used a CP2102 based adapter so I first thought the new Sonoffs were defective. But after switching to a CH340 adapter all problems were gone.