
Sonoff DUALR3 is a development board based on the ESP32 microcontroller using XTENSA architecture.
This board features a maximum CPU frequency of 240 MHz and 4MB flash memory.
About Sonoff DUALR3
Smart relay switch with ESP32 - supports dual-channel control, power metering, and smart home automation.
Sonoff DUALR3 Technical Specifications
🛰️ Connectivity
🧠 Microcontroller
✨ Features
- 40 digital IO pins
- 16 external interrupt pins
- 16 analog input pins
- 19 PWM pins
Sonoff DUALR3 Useful Links
Sonoff DUALR3 Pin Mappings
Below you can find the Sonoff DUALR3 pinout. This development board provides 40 digital IO pins, out of which 16 can be used as external interrupt pins, 16 as analog input pins and 19 pins have Pulse-Width Modulation (PWM).
| Pin | Analog | Touch | PWM | Other |
|---|---|---|---|---|
| 0 | A11 | T1 | ||
| 1 | PWM | TX | ||
| 2 | A12 | T2 | PWM | |
| 3 | PWM | RX | ||
| 4 | A10 | T0 | PWM | |
| 5 | PWM | SS | ||
| 12 | A15 | T5 | PWM | |
| 13 | A14 | T4 | PWM | |
| 14 | A16 | T6 | PWM | |
| 15 | A13 | T3 | PWM | |
| 18 | PWM | SCK | ||
| 19 | PWM | MISO | ||
| 21 | PWM | SDA | ||
| 22 | PWM | SCL | ||
| 23 | PWM | MOSI | ||
| 25 | A18 | PWM | DAC1 | |
| 26 | A19 | PWM | DAC2 | |
| 27 | A17 | T7 | PWM | |
| 32 | A4 | T9 | PWM | |
| 33 | A5 | T8 | PWM | |
| 34 | A6 | |||
| 35 | A7 | |||
| 36 | A0 | |||
| 39 | A3 |
Default Tools for Sonoff DUALR3
| Bootloader tool | esptool_py |
| Uploader tool | esptool_py |
| Network uploader tool | esp_ota |
| Bootloader address | 0x1000 |
| Flash mode | dio |
| Boot mode | dio |
| Maximum upload size | 1280 Kb (1310720 B) |
| Maximum data size | 320 Kb (327680 B) |
The Sonoff DUALR3 development board by default uses esptool_py uploader tool, network uploader tool for Over-the-air (OTA) uploads and esptool_py bootloader tool. The bootloader starts at address "0x1000". Flash mode and boot mode for Sonoff DUALR3 development board by default is dio and dio respectively.


