Feature for enabling IrDA protocol support on ESP32 UARTs

[SNMetamorph]

Component name

uart

Link to component documentation on our website

https://esphome.io/components/uart/

Describe the enhancement

Unlike ESP8266, ESP32 supports IrDA protocol at it's hardware UARTs. But currently, ESPHome does not have way to enable IrDA protocol support.

There are description of configuration bits of UART_CONF0_REG register:

Bits that are directly related to IrDA protocol support:

Name	Description
UART_IRDA_EN	Set this bit to enable the IrDA protocol. (R/W)
UART_IRDA_RX_INV	Set this bit to invert the level of the IrDA receiver. (R/W)
UART_IRDA_TX_INV	Set this bit to invert the level of the IrDA transmitter. (R/W)
UART_IRDA_WCTL	1: The IrDA transmitter’s 11th bit is the same as its 10th bit; 0: set IrDA transmitter’s 11th bit to 0. (R/W)
UART_IRDA_TX_EN	This is the start enable bit of the IrDA transmitter. (R/W)
UART_IRDA_DPLX	Set this bit to enable the IrDA loopback mode. (R/W)

There are example of code which does enabling IrDA support for UART. It does sending serial data through IrDA.

HardwareSerial Serial2(2); // GPIO 17: TXD U2  +  GPIO 16: RXD U2

void setup() {
    Serial.begin (115200); // (USB + TX/RX) to check
    Serial2.begin(115200); // GPIO 17: TXD U2  +  GPIO 16: RXD U2

    // UART_CONF0_REG  Configuration register 0
    // UART0: 0x3FF40020
    // UART1: 0x3FF50020
    // UART2: 0x3FF6E020

    WRITE_PERI_REG( 0x3FF6E020 , READ_PERI_REG(0x3FF6E020) | (1<<16 ) | (1<<10 ) );  // UART_IRDA_EN + UART_IRDA_TX_EN  
}

void loop() {
    Serial.println("Hello");
    Serial2.println("Hello");
    delay(1000);
} 

Thanks for this amazing project to all developers and contributors :)

Use cases

This will be extremely useful since it will make possible for ESP32 to directly interact with IrDA transmitters like TFDU4100. IrDA physical layer is incompatible with UART by default, therefore there is no possibility to directly interacting between IrDA transmitters and microcontroller. For proper working with IrDA, ICs like MCP2120 or TIR1000 are required. Their function is to convert between IrDA physical layer and conventional UART. And these ICs requires additional components in scheme, which makes things too complicated. But ESP32 IrDA support makes possible to completely avoid these complications and instead just directly interact with IrDA transmitters.

IrDA are actively used in devices like electricity meters, so this feature will be useful for external components that implements support for such electricity meters. Also, IrDA could be used as relatively fast wireless UART channel between two ESPHome devices and potentially many other use cases.

Anything else?

More information about IrDA support on ESP32: https://www.espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf

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🏷️ I've automatically added the component: uart label to help categorize this feature request.