Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By Felipe Echanique
Tosog wrote:Hi,

in the meanwhile i've soldered everything on a prototype port, keeping the lines as short as possible, used capacitors but i still had the same problems. Only one thing did get better: the serial communication has no transfer errors now. But it still resets when switching the AC Power.

But! My final solution works now, I am working with this solution for a view days now and never had any problems.
You can find the solution here:

It seems that the problem are the pins acting as antennas... :lol:
I'm going to cut off the reset pin and others may be.
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By Steve Rodgers
#12694 I too have run into this issue with both the ESP-03, and ESP-07/12 My findings are as follows:

My projects are all built on perfboard and soldered. I'm doing that before designing a PCB. I would not attempt to
prototype this on a solderless breadboard. That is just asking for trouble.

Here are my findings so far:

1 . A 5 volt relay coupled with an LDO regulator such as the ncp1117 series all driven from a common supply will experience resets. Looking at the 3.3V rail with my scope, I see spikes of several volts going in both directions on the 3.3V line when the board resets. These spikes have ~50nSec period and ring for a few cycles before they die off.
The LDO regulator has a worst case dropout voltage of 1.2V so the margin is 0.5V with a 5V input (which isn't much)

2. Using a 12 volt relay and a TO-220 LM1117 3.3V LDO regulator (to handle the extra heat dissipated). I did not see this reset problem when switching CFL's (known for thier horrible inrush current), or a space heater (high current) when using the 12volt source and a 12 volt relay. Here, the margin is much better at 7.5V.

3. Sometimes when I connect a clip lead or a ground probe, the ESP8266 will reset. This happens on both the 5V and 12V versions.

4. Adding 100nf from the reset 'rest' pin to 3.3V marginally helped on the 5V board.

5. Touching clip leads to unused I/O's will sometimes cause the ESP8266 to reset on the 5V board, but I have not tried this on the 12V board.

6. Choice of relay seems to be the driver of this issue. The 12Volt relay I'm using has a coil resistance of 780 ohms and is rated for 8A at 250V. It has UL and CSA agency ratings. The dollar 5V 'Qaingi' relay jas a coil resistance of 70 ohms, is rated for 10A at 250V and the 'CCC' safery agency rating.

7. Power supply selection may also play a part. I saw this more often when using the chinese AC-DC modules versus using my lab power supply. I have not yet tried a 12V Chinese power module, but it is on my to-do list.

If I were to guess what is going on: There is a noise immunity issue when working with these modules on prototype breadboards. I'm not sure if it carries over to a PCB design where there could be an opportunity to have better grounding, but I'm not going to risk a PCB design till I fully understand what the issue is.

User avatar
By HolgerW
#12725 My PCB with

No resets since weeks, the ESP-12 have a fimware with counter, i would see if they do a reset.
The ESP-03 doesnt have that counter, but i use it for various equipment, like PC, TV, radio, diskstation ... no problems.

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By FabMira
#12738 Hey man, I've been using Esp with arduino uno, it was doing pretty good until this morning when i turned them on and the esp keep resetting all the time. I haven't change anything since yesterday when it was working fine... how can i fix it? and btw how did you draw the esp on fritzing? I don't have it in my library