I would like to check on one of the issue i'm facing right now regarding on ESP12. I've manage to setup and connect to blynk. One of the issue right now is that I wish to add external power supply to the ESP12 so that I do not need to connect the usb to the laptop all the time.
However when I try to disconnect and reconnect the usb cable, ESP12 couldn't load the previous program. It seems that ESP12 couldn't disconnect from the power source or else the power will be deleted.
Is this a bare ESP-12, then show us how you have connected and powered the module (diagram with parts values).
It could be much easier to use e.g. a WeMos D1 mini, or similar.
Then you can simply plug a cellphone charger in the USB socket to power the module.
Leo..
I don't understand why you think you need the diodes. Your usb-serial adaptor should have a 3.3V setting. For running from external power, get a small 3.3 V regulator module.
Where is the series resistor for that led? You must use one.
If the esp is not running its program at startup, that means that one of two of the gpio pins are not connected to ground or 3.3V as required. Without them, it will just wait for a program upload instead.
I see no current limit resistor for the LED. The ESP8266 outputs are good for only 10mA so there should be a minimum 130 Ohm current limit resistor (2V drop for LED and 3.3V supply).
Thanks for all the feedback guys. I will make the wire short and tidy up the board, will also add additional resistor to limit the current for the LED.
Do you guys knows which pin should be enable high or low in order for the esp to run the program at startup?
raccon82:
Thanks for all the feedback guys. I will make the wire short and tidy up the board, will also add additional resistor to limit the current for the LED.
Do you guys knows which pin should be enable high or low in order for the esp to run the program at startup?
