- Fri Feb 22, 2019 9:33 pm
#80738
VIABLE CIRCUIT? Not at all. I'm surprised at how many things you can do wrong.
You need to have a current limiting series resistor with the LEDs in the optocoupler.
If SW1 is to allow you to go into boot program/upload mode, then it has to be connected to GND and not Vcc.
If SW1 was closed with the circuit as shown the LED will be blown as there is no current limiting resistor. (see above)
The transistor connection to GPIO is backwards. 5 needs to go to GND, 6 to the port pin.
GPIO2 must be high at reset for the ESP8266 to go into the right boot mode. (along with GPIO-0 and GPIO15) If the optocoupler is turned on at reset the board will not start as expected.