Sonoff BasicR3 10A

Sonoff BASIC R3I’m currently blogging about the more expensive 16A Shelly One power controller and already this  summer I’ve written about the Gosund units, but regular readers will be aware that I’m a long-term fan of Sonoff and their various low cost controllers. My most recent acquisition is a pair of Sonoff BasicR3 Power Controllers and I now have a pair of Sonoff Minis on the way.

Gosund have recently confirmed that their current units will NOT support MQTT – and that they’d have to do some redesigning (I don’t understand why an OTA upgrade could not do that, personally)… No matter what, the Sonoff entry-level WIFI power control units are just cheaper than every one elses – it’s that simple. If only they’d all take MQTT as seriously a people like Arendst (Tasmota) and myself who have made replacement firmware for such boards. There are other good examples out there. However, the R3 is an improvement over previous similar controllers.

One of the BasicR3 units is on duty controlling my hot tub pump (we don’t need the heater on in Spain in the summer, just the pump during overnight cheap rate), the other is on my bench on test after suffering a mishap (my fault). I ended up replacing the on-off PCB control button as may be obvious in the photo.

I love these devices, what I’m not 100% convinced about is the firmware. For now, the new Sonoff Basic R3 has DIY firmware for those who don’t wish to use the Sonoff Cloud.

I flashed TASMOTA software onto these devices the old-fashioned way with an FTDI then upgraded to the latest Tasmota release using the Tasmota OTA (over-the-air updates) facility. What I’ve not yet managed is getting the indicator lights right (feel free to step in and advise if you are familiar with putting Tasmota on these particular devices (I have one BASICR3 and one BASICR3 RF – the unit shown in the photos is the RF version – not that I actually use the RF facility as I run these on WIFI).

There are two LEDs on these devices, on mine, the leftmost is RED and should show the state of the relay, the rightmost is blue and should show WIFI connectivity. In fact right now I get only the rightmost blue light which is showing relay status. AND initial WIFI status. I need to get to grips with the Tasmota configuration (most likely the template option)

Sonoff BASIC R3

Here’s the BasicR3 with my )not quite long enough) replacement PCB button (the white glue is theirs, not mine).

Sonoff BASIC R3

Sonoff BASIC R3

Anyone familiar with the Sonoff BASIC will know that the new cases are quite an improvement.

Meanwhile, Itead continue to claim 10 amps capability, I continue to state that this means 10 amps non-inductive load and that you should not try to control a 10 amp inductive heater. Consult an electrician if in doubt. The claims for current capacity are not exlusive to Sonoff, Shelly claim 16 amps for their unit and again that should be considered 16 amps DC, if using an inductive load, the maximum should be lower by several percent.

I ended up flashing these Sonoffs with Tasmota using the excellent NODEMCU Firmware programmer and or course, for putting in the initial WIFI configuration I use YAT – all on my Windows 10 PC.


The rest is done in a web browser using Tasmota’s own web interface and finally onto my own Node-Red setup which includes MQTT. I’ve suggested to Itead that they include MQTT as a standard alternative to their cloud. Time will tell.


20 thoughts on “Sonoff BasicR3 10A

  1. as we tested every single gpio using Travis Griggs (DigiblurDIY) method this morning, i think the red led is not directly connected to a gpio, but used by the rf part of your module… read here:

    Travis method is this: set every gpio (except gpio0, or you’re going to factory reset your device as soon as you turn the “fake” relay ON on that gpio for more than 7 seconds!!!) to a relay, numbering them sequentially… you have 8 total relays in tasmota, from relay1 to relay8, look at image (and one of those 2 relay4 should be relay8, i know…)… continue in next comment…

    1. then save and go to your device web main page, you’ll see a bunch of toggle buttons on top… toggle them 1 by 1, and note which one does what… you’ll soon find which toggles the led, and which the relay…

      then just go again to the module settings page, and change the relayX you noted (because you noted, right?) to relay1 and to led1i (i stands for INVERTED, as on sonoffs leds are on if pulled low, i think, details on tasmota wiki), and all the others back to NONE…

      now start again, and 1 by 1 change 1 of those remaining unused gpios to button1, save each time and after reboot test if button actually works as expected, otherwise revert last gpio to none and go for the next setting always 1 at a time to button1… this way you’ve mapped relay, led and button, easy peasy lemon squeezy (Negan rules)…

      1. It is looking like the RF version does not allow relay monitoring on the RED LED. Shame as I’m not interested in the RF option.

      1. sudo apt-get install -y python3 python3-pip qt5-default pyqt5-dev pyqt5-dev-tools python3-paho-mqtt
        git clone

        cd tdm

        last 2 commands need to be done in a graphical environment, as TDM is a gui program…
        so, directly connected monitor, or vnc… if you don’t have vnc:
        sudo apt-get install -y realvnc-vnc-server
        then in putty run: vncserver
        to get its ip address and port, usually ip:1
        and use a vncviewer from your pc to connect to that address and port

  2. The one thing I’d like is a simple way of connecting an earth. On the old relays, you can just get a small connector inside the case to connect up the earth. Does not look like there is enough room here.

    1. Well, the one thing I would like would be complete isolation from input to output. The tracking these devices use is great for controlling lights but for heating systems I need isolation… not that easy on the Sonoffs and others as there are additional components right next to the contacts.

      1. For what it’s worth, how I use these to switch heavy loads (like geysers and borehole pumps) is to have the Sonoff device switch an appropriately sized contactor instead.

        This increases the overall cost of deployment per unit, but, it’s very effective. Plus, contactors make a satisfying “clunk” noise when engaging.

  3. how to have dry/clean contacts on sonoff basic r3, without cutting the pcb… solder 2 wires, 1 on the 5V pad in the image, and 1 on the GND in bottom left, and power it via an external 5V psu… this way you’ll have a dry contact between the 2 opposite LINE terminals, or you can bridge the line and neutral terminals on one side and have the dry contacts both on the other end…

      1. I’ve played for a while now with the 5V supply…. until now… 🙁

        now it seems that, by applying the external 5V to the above points, the R3 is not more able to boot: the 5V are present anyway, and, when it is connect, they are regulated to 3.3 V on the pins that are used to load the tasmota firmware

        I am still able to boot it by supplying directly the 3.3V on that pin, then connecting the 5V supply, and finally I can disconnect the 3.3V supply.. and then everything is working fine

        any idea why suddenly the 5V supply is no more able to boot the device?

    1. very useful, even for playing with the R3 without the risk associated with the 110/220V voltage

  4. Good point Antonio, aside from the need for a separate power supply – but if one needed a pair of isolated contacts (heating system) though not ideal, this IS a solution if you happen to have 5v power supplies going to waste.. and here all this time I’ve been using the markedly inferior 3v3 supply on my FTDI to power these things for flashing when I could have been using the 5v output…

    1. and before anyone comments about 5v signals on 3v3 comms lines, ESP comms lines are 5v tolerant (power line however is not.

  5. Hi Antonio, wouldn’t you need to separate the AC/DC converter
    – from the power rail input as it may disturb your usage of dry circuit?
    – from the 5V line as it may add useless power consumption?

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