ESP8266 Community Forum

- Sun Jun 19, 2016 2:39 pm #49445 Have ESP-12 (not E or higher). Functioned fine, was able to program sketch via Arduino IDE. Sketch worked OK. Removed power and reapplied power after a few seconds. Sketch failed to run. LED lights brightly. Shorting reset pin to gnd does nothing. Shorting CH_PD to gnd causes LED to be brighter but does nothing else. If I remove power and reapply it a few minutes later, ESP works OK again.

I'm including my circuit. The IO to "Page 1" goes to an ATmega328P. My sketch was a test sketch, it only prints "Hello" to the serial monitor. None of the GPIO pins were used in the sketch.

I really would appreciate some help. Tried a bunch of stuff without success.
Thanks

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- Sun Jun 19, 2016 7:24 pm #49455 Marty,

From your description, especially the part about the LED lighting brighter when the CH_PD button is pressed, it sounds like you have bad power to the ESP. The CH_PD (low) puts the chip into power-down mode and the current will drop drastically, so obviously you have a considerable voltage variation if you can see the difference in the LED brightness. Pop your meter on there and check what the voltage drop actually is.

-John-

- Sun Jun 19, 2016 11:15 pm #49459 Thanks John. Vcc is 3.29V under all circumstances: good and bad operation, and when shorting CH_PD. Checked with a scope Vcc is always clean - no ripple.

Isn't it weird that leaving it sit for a few minutes returns to good and normal operation?

Thought it might be residual charge on 10uF capacitor across Vcc and GND. So I put a 10K bleeder resistor across it to discharge it when power was removed - but that didn't help. Just shorting the cap with power removed didn't help either.

I'll break the connection to Vcc and measure the current to see what that does when CH_PD is shorted.

- Mon Jun 20, 2016 5:56 pm #49507

Isn't it weird that leaving it sit for a few minutes returns to good and normal operation?

Maybe a heat related problem with the ESP12 module itself?