Sonoff SV - what are the other GPIO pins for?

[GSLaaitie (Hendrik Pelser)]

Hi all

I’ve been expanding my collection of connected devices and am now playing around with the Sonoff SV.
Thanks to the incredible guidance by this community I’ve been able to connect it to a switch and a sensor on GPIO14 (like in the famous DrZZs garage video)

My question is about the rest of those pins. The SV has 9 GPIO pins. I’m assuming 4 of those are the 3.3V, RX, TX, and ground pins. One is GPIO14. What are the other for?

Is there a way to connect more sensors to the rest of the pins? Like is there a GPIO13 and GPIO7 that I could connect more reed switches to?

Thanks for all the help!

[tom_l]

Of those 9 pins, 3 are GPIO (Signal), 3 are power (Vcc), and 3 are Ground. Labelled S, V and G respectively on the board.

GPIO4, 5 and 14 are the only 3 GPIO pins you have available:

[GSLaaitie (Hendrik Pelser)]

@tom_l

Of those 9 pins, 3 are GPIO (Signal), 3 are power (Vcc), and 3 are Ground. Labelled S, V and G respectively on the board

Tom, looks like you are my champion. Thanks for this too.

That makes a lot of sense. Can you recommend a place where I can read more in how to use GPIO4 & 5 in the same way as 14? I’m not bad at Googling, but couldn’t really find anything. Can I just assign Switch3 and Switch 4 to GPIO4 and 5?

The board is on Tasmota 8.3.1

[tom_l]

@GSLaaitie

Can I just assign Switch3 and Switch 4 to GPIO4 and 5?

Yes indeed you can. Both those pins have no special caveats. Here’s a handy table that tells you the best pins to use and it looks like Sonoff chose wisely:

[emeyedeejay (MJ)]

Hi all - I’m wondering if anybody knows what these are?

I want to add additional LEDs for the power and status LEDs and a button all external to a case my SV is sitting in.

The button I could solder but the LEDs are tiny and all I’ll end up doing is butchering the board!

[BestGear]

Hi

You have three GPIOs there that you can assign for different uses… as you say, could be an LED but more commonly used for sensors or other devices.

I use these SVs with temperature (18DS20) and humidity (various) as well as mains power measurement (home consumption).

The block of pins provides three GPIO, three power and three ground.

Hope that helps.

David

[emeyedeejay (MJ)]

Thank you for the info …

I just want to confirm that we are talking about the same pins. The block of 9 pins (3x3) I get - it’s the other 9 that I’m curious about. Actually, they are not pins but a header (is that the right word?!). I’m curious about the ones I’ve more carefully highlighted here.

[1berts (Adrian S)]

Hi MJ,
Did you ever find out what the row of headers are?
Do you happen to know what pin the relay is?
Adrian

[emeyedeejay (MJ)]

No - That row of 9 holes remains a mystery.

Just checked and there are traces from there so somebody with a little more PCB smarts than me could probably tell.

GPIO12 is the relay and red led pin - info from here:

Generic Sonoff

[emeyedeejay (MJ)]

I’m not sure if you are using ESPHome but if so, this config is working for the green power indicator LED and the relay with it’s associated red LED.

esphome:
  name: driveway_gate_monitor
  platform: ESP8266
  board: esp01_1m

wifi:
  ssid: "xyz"
  password: "abc123"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Driveway Gate Monitor"
    password: "Bx3SLUgNuBZx"

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO5
      mode: INPUT_PULLUP
      inverted: True
    name: "Driveway gate monitor"
    device_class: door

switch:
  - platform: gpio
    name: "Status LED"
    pin: GPIO13
    inverted: true
    restore_mode: ALWAYS_ON
    
  - platform: gpio
    name: "Relay LED"
    pin: GPIO12
    restore_mode: ALWAYS_OFF
    
    

[CyberMod-Studio]

i also want to know

[tom_l]

@emeyedeejay

it’s the other 9 that I’m curious about

You are the one with the board. Trace them out.

[mlw (Mike W)]

Curiosity got the better of me guys! I traced every pin as good as I could, and found documentation from all over the web.

This depicts a few unlabeled things:

The pinout of those pins resembles closely:

Here’s a view of the bottom:

It looks like the #2 pin is the ADC pin on the ESP chip:

This should mean we can put on a resistor for that and measure analog voltage. Fun.

[mlw (Mike W)]

The site won’t allow me to upload PDF files unfortunatley, but the pic below depicts the most critical notes

[Gadget-SA]

Just an FYI:

On the attached image, is an additional GPIO which I used to use when I had this operating my gate, as the onboard relay was ideal for this use case, but eventually ran out of flash for everything that I wanted to include onto the board, so I moved over to an ESP32-S2 instead.

I basically used GPIO13 as the “Bell Button” (binary switch) for gate door bell on the kitchen node, and GPIO0 had an external straw hat LED connected to it for the “Gate Bell Button Backlight”, with GPIO14 for the reed switch to detect when the gate was open/closed, GPIO12, obviously the relay and GPIO4&5 (SDA & SCL) used for the INA219 to measure current/voltage/power on the gate battery. Never bothered with TX/RX (GPIO1 & 3) as those would have been a pain when having to flash via USB TTL

So, if you ever need an extra pin on the SV, very carefully just solder a wire to the back of the board onto that end of the resistor