ESP8266 Community Forum

What does that SMD Part ?

I have a 12E that makes much trouble with restarts. Even with great Power 2A and that recommend resistore and capaticator rubbish.

After remove the shield it work some better and after remove that SMD Part the 12E works stabile without reboots... but also no WLAN lol



What does that SMD Part with the red cross?


I have order 7 x 12E and 1 x 12F. Most are Buggy... fast reboots only with simple code like

unsign double blabla = 0;
blabla = blabla + 1;
serial print (blabla);

Only 3 work stabile, the other break most time between 250 - 40000.

OK I know it now

it is a 12kOhm resistor.


----------------

About Stability i have found new crazy thing.


1. Brand new 12E oder 12F from Ebay China
2. Self-soldered to adapter board
3. Flash NodeNCU

4. Upload with Arduino IDE 1.81 this code

long zahl = 0;


void setup() {
Serial.begin(115200);
delay(100);
}

void loop() {
Serial.println (zahl);
zahl = zahl + 1;
}

5. In Serial Window it count the numbers up and hang most time between 200 and 3000.

6. Pullup resistors and capacitors easily, better Power-Source improve the problem. But not perfect. Continue crashing.

7. Upload a simple Sketch with Arduino IDE with let connect the ESP12E with Router

8. Upload the same Counter Sketch Number 4 (see up) and the reset Problems are Away... count up to 1 020 000


A very strange thing. Do you know why?

You should also post the message printed to serial monitor upon crashing and/or restart. Restart message indicates why the device crashed, it's printed at 74880 baud rate - you should make it your default baud rate in user_init() and serial monitor.

My preliminary guess would be there is something wrong with your blank.bin or esp_init_data_default.bin files. Did you upload them to flash addresses atleast once. Or does the arduino IDE does that automatically?? Can someone chime in on that; I don't know since I program esp8266 using NONOS SDK.

Why are you flashing with NodeMCU and then using Arduino to program and flash?
Try blanking out the flash and then use Arduino IDE to upload your code.

BUT! Before doing that, add a delay to your loop(). You are sending out Serial.println(zahl) without any delay. Since the ESP is much more faster than your regular UART board, it may actually be the UART board or the terminal software crashing, instead of the ESP. Is the blue LED next to the antenna still blinking (more like on since it's too fast) when you feel it's hanging?

Also, if the ESP ever hangs, the watchdog timer will automatically reboot it with a stack dump (which you should post here). If it does not do that, it's probably something wrong with your code.