WIFI Eight Relay Board




Posted in TechnologyWireless

Introduction: WIFI Eight Relay Board

Safety Warnings

If you are considering buying this item, you probably already know all this but in the interest of your safety, we feel compelled to state all this clearly. So take a few minutes to read it carefully before buying.

AC mains are very dangerous -- Even a 50 V AC supply is more than enough to kill you. Please Switch off the mains before making or changing connections, be very very careful.Ifyour are not sure of anything related to the Ac supply linesplease call an electrician ask him to help you our with it . Do not attempt to interface to mains unless you have adequate training and access to appropriate safety equipment. Never work on high voltages when you are alone by yourself. Always ensure that you have a friend/partner who can see and hear you and who knows how to quickly turn off power in case of an accident. Usee a 1A Fuse in series with the input to the board as a saftey measure. Basic Wiring diagram is available on our instructables page and github .Please go through it

Fire Hazard: Making wrong connections, drawing more than rated power, contact with water or other conducting material, and other types of misuse/overuse/malfunction can all cause overheating and risk starting a fire. Test your circuit and the environment in which it is deployed thoroughly before leaving it switched on and unsupervised. Always follow all fire safety precautions.

Armtronix Wifi Eight relay board is a IOT board.The features of the board are:

  1. Wireless control
  2. HTTP and MQTT
  3. On board USB to UART
  4. On board AC to DC power supp1y 230VAC to 5V DC.
  5. DC virtual switch

The size of the board is 140mmX80mm, as its shown in diagram1. Relays has a capacity to drive 10Amps load. The board has the Wifi module (ESP8266) and microcontroller (atmega328) which is used to control the relays through HTTP or MQTT.There are eight relays on the board, eight loads can be controlled.There is DC virtual switch. There is on board USB to UART and micro USB to program the ESP 8266 and atmega328 using suitable jumper settings.

The board also has Power module AC to DC of 100-240VAC to 5V up to 1A, Relays and Terminal connector.

Step 1: Header Details

The diagram2 gives the details of the headers and terminal blocks.

To board 230VAC is applied to the input terminal block and loads are connected to the output terminal block.

The diagram5 gives the header details of the P1, P2,P3 and P4.

On the board P2 header is used give the 5v or 3.3v to controller, refer the diagram2 this is made by using jumper arrangement. If 1 and 2 pins of P2 is short then the controller runs at 5V, if 3 and 2 pins of P2 are short then controller runs at 3.3V as shown in diagram5.

P1 header is a standard SPI header is used to upload the bootloader to atmega initial(board comes with preloaded bootloader)

P3 header to connect the DC virtual switch

P4 header is for relay , if the jumpers are short then the relay can be turned on and off.

S1 button is for reset of ESP.

S2 button is for Key flash for ESP.

S3 button is reset for Atmega .

Step 2: Programming Header

P5 Header is used to upload the firmware to ESP or atmega through the USB to UART by using micro USB details of headers can be found in the diagram6.

To upload the new firmware to esp via selecting the com port short the pins 2-8 ,3-9 and 5-11 of P5 header using jumper settings., refer the diagram8.

To upload the new firmware to atmega via selecting the com port short the pins 1-7, 4-10 and 6-12 of P5 header using jumper settings, refer the diagram7 .After programming both ESP and Atmega we have to establish connection between ESP and Atmega by shorting 1-2 and 3-4 of P5 header using jumpers settings refer diagram9.

Step 3: Wirring

The wiring diagram is shown in the diagram3 and diagram4 , diagram3 gives the clear picture of about connection of phase and neutral to input terminal block , 230VAC Phase(P) and Neutral(N) . Also gives relay wiring information, phase is given to the common terminal of the relay and load is connected to the NO(Normally open ) termianl of the relay.

The diagram4 shows how to do the wirring of the DC virtual switch. P3 header has the GPIO’s of the atmega which is used for the virtual switch..The user can control the relay channels using wifi based and also using DC virtual switch.

For configuration of ESP refer the configuration details link



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    I am reviewing your board. I have flashed Easy Esp onto it and
    verified that it flashed properly, web UI works fine. I have returned
    jumpers to factory default settings. Jumpers on P4 are all shorted as
    per your instructions.

    When I try to access the gpio pins directly via

    I can see that the device is receiving data and giving the expected
    response. I have also verified this by looking at the logs.

    relay however does not operate. I have tried all the other gpio pins
    listed in your documentation with no results. The board is powered by
    120V AC and this seems to work.

    Is the board defective? The same sequence works just fine with my other esp2866 based devices.

    I have also done this via Node-Red with the same result.

    a suggestion. The esp2866 board is soldered directly to your device.
    Some people like to be able to upgrade or swap boards for various
    reasons. Failure of a $8 chip in this case would also render a $50
    board worthless. Perhaps a future version could allow esp2866 board to
    be inserted into a socket for easy repair/upgrade/swapping.

    3 replies

    The board has both esp8266(ESP12F) and Atmega328p (Arduino UNO). Communication between the two is via UART . Also if you have changed the esp firmware, you will also need to change the Atmega328p firmware as the relays are connected to Atmega328p .And when ever esp receives any command via wifi ,appropriate commands has to be sent to atmega328p via uart for the relay to trigger . I hope you are doing this.

    Thank you for your prompt reply. One other question. I was looking for the source code on github so I can see how you interfaced. I found only armtronix/NodeMCU_four_relay_board

    Is the code for the 8 relay board the same as the four or am I looking in the wrong place?