Robca It took me forever to figure it out. I thought it was only my unit, but I see it's not the case, and it's clearly a design defect. You need to have Bluetooth playing, press the Play-Pause button, switch to Aux with the M button, then press Play. Usually it starts then playing the Aux-RCA source. You can press Play-Pause and it mutes Aux, then again to restore the sound. Once you turn it off, you need to repeat the process to select Aux. Basically Aux cannot be used unless you have a Bth source first (I think you can play from USB-TF also first)

Robca No, unless you file them or cut them down. The "legs" are just part of the bottom plastic part

Robca Yes. Use this library for the display github Bodmer TFT_eSPI and it will work well. If you look on github for Tetris Clock and "TTGO_example", you will find a library and example I wrote for this board. It has an explanation page that shows how the board looks when running it

Robca It is on mine (but mine has a different handle)

Robca The ones in the picture look like Hakko T12/T15 clones. Look for T12 tips, plenty of documentation for every one of those Unlike the other answer says, the ones used in the soldering iron do not look anywhere like the TS100 tips (which are modeled after the T12, but shaped differently)