Hi Arv Evans,

I'm a complete newbie to Amateur Radio but not electronics Arduino's etc. I have used the same ? level converters in an Usb Rs232 5 volt logic to 3.3 ? logic conversion when uploading code to my Esp8266's. All the Esp' logic pins including Tx and Rx run on 3.3 and are rather intolerant to 5 volts. It's really the 3.3 volt Rx into the Esp that matters. I have flashed / Arduino sketches into Esps at least 100 times with no issues.(I have around 8 Esp's some have their Rx pins fried as I tried using 5 volts. Never trust a Usb to Rs232 if it states 3.3 logic without checking.).

Esp's in CERTAIN areas easily rival Arduino's

Owen Vk5fkov