Sonoff IFAN04 with ESPHome
This ESPHome configuration file reproduces the functionality of the original IFAN04 firmware. Additinally it enbles the use of the I2C bus.
IFAN04 has a ESP8266 with 1 MB flash.
The RF remote control receiver communicates with the ESP8266 via the UART0 serial interface. Baudrate is 9600.
The fan and light is controlled with four relays.
To use the I2C interface of the ESP8266 the SDA and SCL pins can be accessed through the test pins (TP10, TP11) on the backside of the PCB.
| ESP pin | assignment | comments |
|---|---|---|
| GPIO0 | Button | |
| GPIO1 | UART0 TX | |
| GPIO3 | UART0 RX | RF remote control receiver |
| GPIO4 | I2C SDA | TP11 D_RX on the PCB backside |
| GPIO5 | I2C SCL | TP10 D_TX on the PCB backside |
| GPIO9 | Light relay | D7 on the PCB backside |
| GPIO10 | Buzzer | |
| GPIO12 | Fan relay 2 | D11 on the PCB backside, 3 uF on IFAN04-H |
| GPIO13 | LED | |
| GPIO14 | Fan relay 1 | D5 on the PCB backside, 2.5 uF on IFAN04-H |
| GPIO15 | Fan relay 3 | D13 on the PCB backside, no cap |
The three different speeds (low, mid, high) are controlled via the three fan relays as follows.
| Fan speed | used relays |
|---|---|
| low | 1 |
| mid | 1 + 2 |
| high | 3 |
The original firmware has also the following special timing sequence when activating the different speeds.
| Fan speed | timing sequence |
|---|---|
| low | relay 1 + 2 are turned on, after 5 seconds relay 2 is turned off |
| mid | relay 1 + 2 are turned on |
| high | relay 1 is turned on, after 5 seconds relay 3 is turned on and relay 1 is turned off |
RF remote control receiver sends the remote control commands via the serial interface UART0 to the ESP8266.
These commands consits of 8 bytes. The first two bytes are always 0xAA55 and the last byte is a checksum of the bytes 3 to 7, the command code.
To receive and use these commands in ESPHome the serial data is processed by a custom text sensor component.
This text sensor component is implemented in the ifan_remote.h file and receives and translates the commands of the remote control into the following text strings.
| RC button | text string | label |
|---|---|---|
| 1 (left-top) | 0104000104 | Light on/off |
| 2 | 0106000101 | Mute |
| 3 | 0104000103 | High speed |
| 4 | 0104000102 | Medium speed |
| 5 | 0104000100 | Fan off |
| 6 | 0104000101 | Low speed |
| 7 | 0101000102 | RF clearing |
| 8 (right-bottom) | 0101000102 | Wi-Fi pairing |
The two bottom buttons are sending the same command code to the ESP8266.
The custom text sensor is implemented in the configuration file as follows:
esphome:
includes:
- ifan_remote.h
logger:
baud_rate: 0
uart:
rx_pin: GPIO03
baud_rate: 9600
id: uart_bus
text_sensor:
- platform: custom
lambda: |-
auto ifan_remote_sensor = new IFanRemote(id(uart_bus));
App.register_component(ifan_remote_sensor);
return {ifan_remote_sensor};
text_sensors:
name: 'RC command'
on_value:
then:
- if: # Light on/off
condition:
lambda: return x == "0104000104";
then:
...
As you can see to use the RF remote control the uart debugging must be disabled by setting baud_rate: 0 in the logger-configuration.