Add Waveshare Pico DALI2

Author: arendst

docs/DALI.md

@@ -42,6 +42,10 @@ Initial implementation has been performed using [DALI Click](https://www.mikroe.
 
 A redesigned version called [DALI 2 Click](https://www.mikroe.com/dali-2-click) also works fine whith GPIO settings `DALI TX_i` and `DALI RX_i`.
 
+## Waveshare Pico DALI2
+
+This cheap [DALI2 expansion Module](https://www.waveshare.com/pico-dali2.htm) for ESP32-Pico series boards works fine with a Waveshare [ESP32-S3-Pico](https://www.waveshare.com/ESP32-S3-Pico.htm) using GPIO14 as `DALI RX` and GPIO17 as `DALI TX_i`. The Waveshare [ESP32-C6-Pico](https://www.waveshare.com/ESP32-C6-Pico.htm) has no GPIO connection to the Pico DALI2. At the physical locations of the Pico DALI2 signals it uses a Texas Instruments TCA9554 I/O expander, compatible with PCF8574, providing ExIO1 (`DALII TX_i`) and ExIO2 (`DALI RX`). This is currently not supported by Tasmota.
+
 ### Shelly DALI Dimmer Gen3
 
 <img alt="ShellyDali" src="../_media/dali_tasmota_main.png" style="margin:10px;float:right;width:20em"> </img>