user51992: Whenever I boot up the esp8266 or flash code via usb ,I have to remove vin pin otherwise it does not boot up.
If I remove vin pin then flash and boot up happens and then i am able connect vin with 5 V relay.(using VIN to power up relay) .
I dont understand what it has to do with VIN pin.please suggest.
I am using below pins for eight devices
//relay pin setup for funct
int relayOne = 5;
int relayTwo = 4;
int relayThree = 0;
int relayFour = 2;
int relayFive = 14;
int relaySix = 12;
int relaySeven = 13;
int relayEight = 15;


user37622: IO pins 0, 2 and 15 are boot configuration pins. 15 must be LOW at boot, 2 must not be LOW at boot and 0 determines the flashing mode. For normal run pin 0 must be HIGH. The NodeMcu board has necessary pull-up and pull-down circuits.
You can connect to pins 0, 2 and 15 only devices which don't change the boot state.

51992: <p>Whenever I boot up the esp8266 or flash code via usb ,I have to remove vin pin otherwise it does not boot up.</p>

<p>If I remove vin pin then flash and boot up happens and then i am able connect vin with 5 V relay.(using VIN to power up relay) .</p>

<p>I dont understand what it has to do with VIN pin.please suggest.</p>

<p>I am using below pins for eight devices</p>

<pre><code>//relay pin setup for funct
int relayOne = 5;
int relayTwo = 4;
int relayThree = 0;
int relayFour = 2;
int relayFive = 14;
int relaySix = 12;
int relaySeven = 13;
int relayEight = 15;
</code></pre>
 37622: <p>IO pins 0, 2 and 15 are boot configuration pins. 15 must be LOW at boot, 2 must not be LOW at boot and 0 determines the flashing mode. For normal run pin 0 must be HIGH. The NodeMcu board has necessary pull-up and pull-down circuits.</p>

<p>You can connect to pins 0, 2 and 15 only devices which don't change the boot state.</p>
