ITEAD’s Sonoff Basic R3 has expanded. Apart from the WiFi version that we all know and like, there is an RF (433 MHz) and Zigbee. Since the hardware had changed as well I thought I would take each Sonoff Basic R3 apart and poke inside the modular design.

Sonoff Basic R3 series

On the outside, all 3 look the same. A white uniform shell with only model numbers at the back distinguishing one from another. It’s a shame, as I had to use a marker pen to be able to quickly tell the difference. The biggest selling point of the R3 series was the DIY mode, but the implementation of it is lacking and you can read about shortcomings of the DIY Mode here.

Inside you will find a redefined, modular design. Sonoff Basic R3 series is divided into 2 parts: the relay board and connectivity interface. The design principle isn’t 100% consistent so I decided to poke around more.

Before I start to dissect each board, during my teardown, I’d like to point out a couple of things. Despite the connectivity module using two sets of 4 pins, these are not the standard GPIO pitch (2.54mm). The pins are not only narrower but also packed densely (1.7mm). Unfortunately, my idea of using GPIO headers to create the detachable modules failed.

The exposed pins come with the 2.54mm pitch and you can solder the standard Raspberry Pi header. The number of pins varies between 4 and 5.

The button is still very fragile, so take extra care during assembly and disassembly.

Sonoff Basic R3 WiFi

This is the most basic module. Comes with WiFi, DIY Mode and not much else.

Relay board

The relay board comes with GI-1A-5DH relay capable of 10A. The board has a couple of components removed, which confirms that the same PCB is used for every Sonoff R3 board.

You can access 3.3V and 5V directly from the PCB as there are two sets of dev pads exposed.

The main voltage (AC) is separated from the circuit and in the narrower point it comes close to 2.4mm (reinforced with physical separation.

Connectivity module

The WiFi connectivity is provided thanks to ESP8285. There are DIY Mode pins that you can short to enable the DIY mode and additional pins Vcc, GND, TX, RX for you to use. These are the standard GPIO pins.

The connectivity module uses 2×4 headers to communicate with the board. The pins are mapped to 3.3V, 3.3V, GND, GND and RELAY, RF_INT, RF_LED, KEY. Additional 3,3V and GND pads are also available.

Sonoff Basic R3 WiFi + RF

This module comes with WiFi as well as RF 433MHz interface. You can also order a 4 button RF controller to operate your RF modules.

Relay board

The PCB has all components soldered to it, which means that was the matrix PCB for all Sonoff R3 series. The relay board comes with GI-1A-5DH relay capable of 10A.

The relay board contains the RF antenna and circuit to control the relay with a 433MHz signal.

You can access 3.3V and 5V directly from the PCB as there are two sets of dev pads exposed.

The main voltage (AC) is separated from the circuit and in the narrower point it comes close to 2.4mm (reinforced with physical separation.

Connectivity module

The connectivity module is identical with Sonoff Basic R3. It uses ESP8582 to communicate with the Internet and the same pins are exposed for you to use: Vcc, GND, TX, RX – These are the standard GPIO pins.

The connectivity module uses 2×4 headers to communicate with the board. The pins are mapped to 3.3V, 3.3V, GND, GND and RELAY, RF_INT, RF_LED, KEY. Additional 3,3V and GND pads are also available.

Sonoff Basic R3 Zigbee

The youngest in the family, this board comes with Zigbee only interface. This means you will need a Zigbee hub to use the module. ITEAD provides you with one, or you can take advantage of the CC2531 Zigbee USB stick. You can read more about using Sonoff Basic R3 Zigbee and Tasmota here.

Relay board

As with Sonoff Basic R3 board comes with GI-1A-5DH relay capable of 10A. This is exactly the same layout as well.

You can access 3.3V and 5V directly from the PCB as there are two sets of dev pads exposed.

The main voltage (AC) is separated from the circuit and in the narrower point it comes close to 2.4mm (reinforced with physical separation.

Connectivity module

Unlike other Sonoffs, this one comes with a CC2530 module to connect with Zigbee hubs. There is no WiFi, but CC2530 will act as a Zigbee router relaying the messages from other devices.

This time, there are 5 pins exposed, Vcc, GND, RST, Data, Clock which suggests that you could use the I2C interface.

The connectivity module uses 2×4 headers to communicate with the board. The pins are mapped to 3.3V, 3.3V, GND, GND and RELAY, RF_INT, RF_LED, KEY. Additional 3,3V and GND pads are also available.

Buy Sonoff Basic R3 Zigbee Buy it using these links to support NotEnoughTech. Banggood AliExpress ITEAD store

Conclusion

Going modular is definitely a way forward. I only wish the connectivity modules were actually snap on (instead of soldered) and make the DIY mode as useful as Shelly 1 API access is. Next up, I will be looking at integrating Sonoff Basic Zigbee with cc2531 and I will see if the stock firmware is good enough or should I try the new Tasmota with Zigbee. What do you think? Let me know in this Reddit thread.