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I have been struggling for some time now trying to get my ESP8266 ESP-12 to work. I was able to get it loaded with the NodeMCU software. Now, the board constantly restarts itself. Whether I have a script loaded on it or not, the module seems to continually restart. I am using ESPlorer, and can see it get connection to NodeMCU. Then the board restarts several seconds to several mins later. I have tried various pinout, capacitors, etc. with no luck in solving this problem. I have been searching all over and have had no luck finding a solution. Any help is greatly appreciated. Here is my current pinout:

ESP-12          -----------      TTY 3.3v Serial
================================================
TX ----------------------------- RX    
RX ----------------------------- TX    
GND, GPIO15 -------------------- GND    
VCC, CH_PD, GPIO0, (RST) ------- LD1117v33 voltage regulator +3.3v    
GND, GPIO15 -------------------- LD1117v33 voltage regulator GND

Thanks so much in advance for any help!

mpromonet
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RMK-Jacob
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  • Have you flashed it with the latest firmware? https://github.com/nodemcu/nodemcu-firmware/releases/tag/0.9.6-dev_20150704 – wordsforthewise Jul 07 '15 at 04:07
  • @wordsforthewise Yes, I have flashed it with the latest firmware. Still no luck :/ – RMK-Jacob Jul 10 '15 at 20:46
  • My ESP8266 restarts constantly if I use the DHT on pin 6... super weird. Not sure if it's because I'm also running Blynk, but switching to any other pin fixes the restart issue. – Nick Bolton Jun 15 '21 at 18:34

7 Answers7

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Assuming the hardware is okay and the right binary is loaded it's almost surly a power problem.

1) Make sure what ever voltage regulator you're using is rated for 200mA or more. In your case the LD1117 can source 800mA so that's good.

2) Make sure you're upstream power supply can source 200mA or more. If you're powering from a USB hub make sure the hub is powered.

3) Make sure you have some large low ESR capacitors across GND and 3.3v. Two capacitors: 10uF and 100uF worked for me (there's nothing magic about these exact values, 10-100uF should work). The ESP8266 can draw huge (relatively) amounts of current for short periods while booting or transmitting. This can cause a bad transient on the power supply, which will cause the system to reboot, which can lead to an infinite reboot cycle.

user1816847
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  • What do you mean by 'bad transient on the power supply'? I'm working from an ANKER USB battery that says it's good for 2A 5V. I'm working with some DS18B20 single wire temperature sensors. I can go up to 12 and I'm good, but adding more and the NodeMCU Wifi board never boots to http server and get's stuck in a blue led blinking reset cycle. – user391339 Feb 14 '18 at 19:58
  • I mean a transient voltage drop either due to the sudden loading of the power supply or the IR drop across the wires or both. Power supplies aren't magic they're dynamical systems and a fast change in current can cause the voltage to change quickly. A supply capacitor near the ESP8266 can help smooth out the current demanded by the ESP8266 when starting wifi. – user1816847 Feb 15 '18 at 21:19
  • @user1816847 Can you please tell me how to connect the capacitor to ESP? I'm curious if it has to be directly on ESP between 3.3 and GND or could it be done on the breadboard where those 3.3 and GND are extended? – Ouroboros Apr 23 '18 at 08:17
  • I'd put it as close as you can reasonably get it. In your case it sounds like the breadboard is the best place. – user1816847 Apr 24 '18 at 19:08
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ESP8266 running lua goes to panic mode if the program loaded on it is has some bug.

Look at your code again. Reflash the firmware and upload code again. Try to upload code bit by bit. So that you know which part is causing the issue.

fix the setup in such way that flashing firmware is super easy. Trust me you will need to reflash it many times if you wanna play with code on it.

Talha
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  • Thanks for this answer. When programming NodeMCU (ESP8266) with Arduino IDE, it goes through this problem a runtime error in the code. –  Dec 05 '19 at 11:47
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I had a NodeMCU dev board which worked fine for some hours, then suddenly restarted and wouldn't stay up. I tried adding power-supply capacitors and using a different power supply, to no avail.

What fixed it for me was resetting the watchdog timer every second:

tmr.alarm(6, 1000, 1, function() tmr.wdclr() end)

The watchdog timer needs to be reset periodically. I don't know how often. My device was resetting after about 35-40 seconds uptime. My code (which ran every 30 seconds from timer) was resetting the watchdog itself. This was not enough, somehow.

nickandrew
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Use a pullup resistor on the RST line rather than just connecting it directly to VCC. I used 4.7K, but the actual value is not critical.

mkarliner
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Get the serial terminal program named "terminal v1.9b by br@y++". While I wrote this answer I was not able to download. When I find the link I'll add in a comment. Run the program and set the baud rate to custom and enter the value 74880 or 74400. With this you'll be able to see the fw messages. In this messages there is the reboot reason code. The codes are :

  • 0 -> normal startup by power on
  • 1 -> hardware watch dog reset
  • 2 -> software watch dog reset (From an exception)
  • 3 -> software watch dog reset system_restart (Possibly unfed wd got angry)
  • 4 -> soft restart (Possibly with a restart command)
  • 5 -> wake up from deep-sleep

Looking at the provided code you can decide from what reason the chip is restarting.

Mert Gülsoy
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If your hardware is good, then the problem should be inside your code. And sometime your code takes too long to finish, then it will trigger the watchdog to restart.

forqzy
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I suggest that you connect your reset pin to 3.3v via a 10K ohm resistor and to ground via a push button. This way your reset pin is always pulled high to prevent the random resets. I assume that your code has no bugs.

Rufusy
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