Let me chime in with a few thoughts, can’t go into full detail since I’m currently traveling and on my phone:
It should be possible to power the BlueRetro using the controller port only. IIRC, the controller pins providing power are directly connected to the internal NES regulator, so with enough headroom to spare, you should be good to go. Eventually, this will depend on the firmware of the ESP-WROOM module used by the BlueRetro (max. current draw for the ESP32 should be around 250mA with all peripherals enabled and transmitting, I’d expect the BlueRetro to use quite a bit less in normal operation). That’s also what the 8BitDo is doing, running at around 100mA.
If you look at YouTube videos, you’ll also find one or two people running the BlueRetro directly off of the port.
Where did you get the level shifter cable from?
I’d also like to know the results of your voltage measurement in operation
If push comes to shove and you decide to replace the LDO, the TLV1117LV made by TI would be a potential candidate, should be a drop-in replacement with better specs (price is about $0.30)
Let me chime in with a few thoughts, can’t go into full detail since I’m currently traveling and on my phone:
If you look at YouTube videos, you’ll also find one or two people running the BlueRetro directly off of the port.
Where did you get the level shifter cable from?
I’d also like to know the results of your voltage measurement in operation
If push comes to shove and you decide to replace the LDO, the TLV1117LV made by TI would be a potential candidate, should be a drop-in replacement with better specs (price is about $0.30)