Your new topic does not fit any of the above??? Check first. Then post here. Thanks.

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User avatar
By donsergio
#83832 Hi, I have a relay module for ESP-01 and when I power it the relay close and open (because IO0 state is high at startup for short time)....

Is any way to do that no high output for IO0 at startup?


User avatar
By QuickFix
donsergio wrote:Is any way to do that no high output for IO0 at startup?

No, GPIO0 has to be pulled high at boot to enable running-mode: a low-state would set the ESP into upload-mode. :idea:
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By donsergio
#84157 Hi, but... I have this board, the board of the pic in the main post.... when power on the board the relays turn on and off.... this is the "trouble that I have".... the IO0 for a while, when power up ESP8266 it get high state for a short time.... enough to energize the relay....
User avatar
By QuickFix
#84198 Read this post: GPIO Pin states after reset/during startup:
RFZ wrote:Hey,
GPIOs 4 and 5 are the only ones that are always high impedance. All others do have internal pull-ups or are even driven low/high during boot.

GPIOs 3, 12, 13 and 14 pulled HIGH during boot. Their actual state does not influence the boot process.

GPIOs 0, 1, 2 and 15 are pulled HIGH during boot and also driven LOW for short periods.
The device will not boot if 0, 1 or 2 is driven LOW during start-up.

GPIO 16 is driven HIGH during boot, don't short to GND.

Or this one: On powerup, GPIO state, relay drive problem
Or even this one: Prevent GPIO 2 keep in High voltage when reboot ESP8266
This topic as well: ESP8266-01 Boot up GPIO spike

And there are many, many more topics about this subject... :idea: