I have an interesting case, the circuit is soldered so it is difficult to swap ESP. It sees the network and does not want to connect to it, ESP not on the board works without a problem. Is it something interference from outside(other chips)? - I supply power from USB Is it a faulty board? Or any...

It would be best if you showed a diagram of your board.

. Show the piece of code where these kinds of problems occur.

Code: C / C++Log in, to see the code .

You wrote that you have this ESP32 soldered into the board. Is this the cube itself or the module with the ESP32? It would be good if you posted a picture of both sides of the board where this ESP32 is soldered. For testing though, it's better to power it from a more stable 5V source than a USB port. . Then show how you initialise WiFi.config().

I don't even initiate anymore, I just upload an example i.e. download after DHCP. I think I have 2 damaged ESP modules, I mean the processor. The one as written connects once in 10 times. Always the first one when it is cold. The other one does not program itself, it sees it but does not respond :/ The other two work. These are modules, some kind of WEMOS clones. Only that I have to change them to see if it is the influence of some periphery. As a curiosity, the device will control the greenhouse (watering, irrigation, lighting, ventilation) and the watering of the vegetable garden.

You can still check how the antenna works in these ESPs. Fire up some sample program that runs the ESP in AP mode. Then use the WiFi scanner on your tablet/phone to check the signal strength from the ESP.

Problems with WIFI operation are usually power supply related, sometimes replacing the cable with a shorter one, adding a capacitor at the power pin helps. The boards are made some better, some worse, sometimes you have to run a soldering iron over the pins. Admittedly I associate Wemos mainly with ESP8266, but I actually found something similar on Aliexpress with ESP32, only the capacitors on this module look very poor compared to e.g. DOIT Devkit V1.

They have ESP-32S on board, or ESP-WROOM-32?

It is something like this What difference does it make what it is? I've read about ESP32 and there are several versions of the chip itself but they don't differ much.

. These are OK, but these modules are not from Espressif. The original ones from Espressif are described here:

ESP32 does not connect to WiFi - USB power, interference, faulty board?

Przybyłek 3150 12

Treść została przetłumaczona

Zobacz oryginalną wersję tematu

Report a violation of the law

Reply | New topic

#1 17998325 06 Jun 2019 00:07

Przybyłek Przybyłek

Level 14

Posts: 208

Help: 1

Rate: 43
» | Topic author

Post #1
17998325 06 Jun 2019 00:07

I have an interesting case, the circuit is soldered so it is difficult to swap ESP.

It sees the network and does not want to connect to it, ESP not on the board works without a problem. Is it something interference from outside(other chips)? - I supply power from USB
Is it a faulty board?
Or any other idea?
Scanning the wifi networks it shows me both but doesn't connect. Sometimes after a day of idling it will connect 3-8 times and then it won't connect anymore. The program only connects to the wifi with a static IP.
ADVERTISEMENT
#2 17998359 06 Jun 2019 00:42

piterek-23 piterek-23

Level 33

Posts: 3321

Help: 162

Rate: 426
» | Helpful post? (0)

Post #2
17998359 06 Jun 2019 00:42

It would be best if you showed a diagram of your board.
ADVERTISEMENT
#3 17998613 06 Jun 2019 10:14

Anonymous Anonymous

Level 1

» |

Post #3
17998613 06 Jun 2019 10:14

Przybyłek wrote:
Scanning the wifi networks it shows me both but doesn't connect. Sometimes after a day's downtime it connects 3-8 times and then no longer wants to connect. The program only connects to the wifi with a static IP.
.
Show the piece of code where these kinds of problems occur.
#4 17998656 06 Jun 2019 10:46

Przybyłek Przybyłek

Level 14

Posts: 208

Help: 1

Rate: 43
» | Topic author Helpful post? (0)

Post #4
17998656 06 Jun 2019 10:46

Code: C / C++
Log in, to see the code
.
ADVERTISEMENT
#5 17998673 06 Jun 2019 10:54

Anonymous Anonymous

Level 1

» |

Post #5
17998673 06 Jun 2019 10:54

You wrote that you have this ESP32 soldered into the board. Is this the cube itself or the module with the ESP32? It would be good if you posted a picture of both sides of the board where this ESP32 is soldered. For testing though, it's better to power it from a more stable 5V source than a USB port.

Przybyłek wrote:
The software only connects to wifi with a static IP.
.
Then show how you initialise WiFi.config().
#6 17998731 06 Jun 2019 11:29

Przybyłek Przybyłek

Level 14

Posts: 208

Help: 1

Rate: 43
» | Topic author Helpful post? (0)

Post #6
17998731 06 Jun 2019 11:29

I don't even initiate anymore, I just upload an example i.e. download after DHCP. I think I have 2 damaged ESP modules, I mean the processor. The one as written connects once in 10 times. Always the first one when it is cold. The other one does not program itself, it sees it but does not respond :/ The other two work. These are modules, some kind of WEMOS clones. Only that I have to change them to see if it is the influence of some periphery.
As a curiosity, the device will control the greenhouse (watering, irrigation, lighting, ventilation) and the watering of the vegetable garden.
#7 17998747 06 Jun 2019 11:49

Anonymous Anonymous

Level 1

» |

Post #7
17998747 06 Jun 2019 11:49

You can still check how the antenna works in these ESPs. Fire up some sample program that runs the ESP in AP mode. Then use the WiFi scanner on your tablet/phone to check the signal strength from the ESP.
#8 17998944 06 Jun 2019 14:11

kaczakat kaczakat

Level 34

Posts: 1748

Help: 317

Rate: 229
» | Helpful post? (0)

Post #8
17998944 06 Jun 2019 14:11

Problems with WIFI operation are usually power supply related, sometimes replacing the cable with a shorter one, adding a capacitor at the power pin helps. The boards are made some better, some worse, sometimes you have to run a soldering iron over the pins. Admittedly I associate Wemos mainly with ESP8266, but I actually found something similar on Aliexpress with ESP32, only the capacitors on this module look very poor compared to e.g. DOIT Devkit V1.

Helpful post? Buy me a coffee.
#9 17998956 06 Jun 2019 14:19

Anonymous Anonymous

Level 1

» |

Post #9
17998956 06 Jun 2019 14:19

Przybyłek wrote:
These are modules, some WEMOS clones.

They have ESP-32S on board, or ESP-WROOM-32?
ADVERTISEMENT
#10 18002593 08 Jun 2019 23:02

Przybyłek Przybyłek

Level 14

Posts: 208

Help: 1

Rate: 43
» | Topic author Helpful post? (0)

Post #10
18002593 08 Jun 2019 23:02

It is something like this

http://esp32.net/images/LilyGO/Pro-ESP32/WeMos-fake_Pro-ESP32_DiagramPinout.jpg

What difference does it make what it is? I've read about ESP32 and there are several versions of the chip itself but they don't differ much.
#11 18002606 08 Jun 2019 23:22

Anonymous Anonymous

Level 1

» |

Post #11
18002606 08 Jun 2019 23:22

Przybyłek wrote:
This is something like that
.
These are OK, but these modules are not from Espressif.

Przybyłek wrote:
I've read about ESP32 and there are several versions of the chip itself, but they don't differ much.

The original ones from Espressif are described here: https://docs.espressif.com/projects/esp-idf/en/latest/hw-reference/modules-and-boards.html
#12 18002847 09 Jun 2019 09:38

Anonymous Anonymous

Level 1

» |

Post #12
18002847 09 Jun 2019 09:38

Przybyłek wrote:

Code: C / C++
Log in, to see the code

.

Throw it to a loop additionally write code that if not connected it should retry the connection....

I also had this problem with it automatically connecting by itself, a reset or switching it off helped, but since I switched this function from setup to loop the problem is gone.

And secondly are you using RTOS? Are you using the first core of the CPU?
#13 18003054 09 Jun 2019 11:59

Anonymous Anonymous

Level 1

» |

Post #13
18003054 09 Jun 2019 11:59

Jarzabek666 wrote:
since I flipped this function from setup to loop I have got the problem over with
.
Whether it is in setup() or in loop() it will automatically be found in one FreeRTOS task (loopTask - code below), which is assigned to the CONFIG_ARDUINO_RUNNING_CORE core (default value 1). I don't know if flipping the WiFi connection check from setup() to loop() will help, but from the FreeRTOS point of view it is still the same "loopTask".
However, the RTOS-SDK functions related to the WiFi stack execute on core 0 by default.
Code: C / C++
Log in, to see the code
.

P.S. The author is already using FreeRTOS, as the Arduino HAL in ESP32 is based entirely on RTOS-SDK.
Create an account, log in here. You will receive points by participating in discussions.
Join this discussion.

Install Elektroda application

Didn't find an answer? Ask Artificial Intelligence

*I agree to send the question to OpenAI, Anthropic PBC, Perplexity AI, Inc., Kagi Inc., Google LLC - owners of language models in order to prepare the best response. The companies may monitor and log information entered into the form.

*I agree to publicly display my question and answer. The question and answer will be publicly available to everyone. The process may take a few minutes. Upon completion, you will be redirected to the page with the answer.

Wait...(2min)

Reply | New topic

Report a violation of the law

Topic summary

✨ The discussion revolves around an ESP32 module that intermittently fails to connect to WiFi despite detecting the network. The user suspects potential issues such as interference from other components, power supply instability from USB, or a faulty board. Responses suggest checking the board's wiring and power source, using a more stable 5V supply, and examining the antenna's performance. The user mentions using WEMOS clones of the ESP32, which may have quality variations. Suggestions include implementing a retry mechanism in the code for WiFi connection attempts and considering the differences between various ESP32 modules. The conversation highlights the importance of proper initialization and configuration in resolving connectivity issues.
Generated by the language model.

Home page
/
Forum
/
Smart Home
/
Smart Home IoT
/
ESP8266 and ESP32
/
ESP32 does not connect to WiFi - USB power, interference, faulty board?

FAQ

TL;DR: ESP32 Wi‑Fi needs >=500 mA headroom; "Provide at least 500 mA." Most "won’t connect" cases trace to power, antenna, or blocking code. Use a stable 5 V source, short cable, decoupling, and retry logic. For makers whose ESP32 sees SSIDs but won’t associate. [“ESP32 Hardware Design Guidelines”]

Why it matters: You’ll fix flaky ESP32 Wi‑Fi fast and avoid chasing phantom firmware bugs.

Quick Facts

Power integrity: ensure a 3.3 V rail capable of >=500 mA and place 10 µF + 0.1 µF decouplers close to VDD. [“ESP32 Hardware Design Guidelines”]
Don’t trust random USB ports; test with a stable 5 V supply instead of PC USB. [Elektroda, khoam, post #17998673]
Antenna sanity-check: run AP mode and measure RSSI on a phone Wi‑Fi scanner. [Elektroda, khoam, post #17998747]
Clone risk: many “WEMOS‑style” ESP32 boards aren’t Espressif modules; originals are documented as ESP‑WROOM‑32. [Elektroda, khoam, post #18002606]
Tasking: Arduino‑ESP32 loopTask runs on core 1; Wi‑Fi driver runs on core 0 by default. [Elektroda, khoam, post #18003054]

Why does my ESP32 see Wi‑Fi but never connect on USB power?

Brownouts and noise from weak USB ports cause handshake failures. Use a stable 5 V supply, a short cable, and add a capacitor at the power pin. Reflow suspect solder joints on clone boards. “WiFi problems are usually power‑supply related.” [Elektroda, kaczakat, post #17998944]

How can I test if the antenna or module is the problem?

Put the ESP32 in AP mode and measure signal strength from a phone. Move a few meters away and compare RSSI with a known‑good board. If RSSI is far lower, suspect antenna layout or damage.

Flash AP example.
Scan with a phone and note RSSI.
Compare vs another ESP32 at the same spot. [Elektroda, khoam, post #17998747]

Will moving Wi‑Fi connect code from setup() to loop() fix it?

Not by itself. setup() and loop() run in the same FreeRTOS task on core 1. The Wi‑Fi stack executes on core 0. Add timeouts and retries rather than an infinite wait. “Arduino HAL in ESP32 is based entirely on RTOS‑SDK.” [Elektroda, khoam, post #18003054]

How should I set a static IP on ESP32 (Arduino) so it actually connects?

Set network parameters before connecting. Call WiFi.config(localIP, gateway, subnet, dns) before WiFi.begin(ssid, password). Ensure gateway and DNS match your router’s subnet. Mismatched settings silently prevent association. [“ESP32 Arduino: WiFi Library”]

Does USB cable length really affect ESP32 Wi‑Fi reliability?

Yes. Long or thin cables drop voltage during Wi‑Fi bursts, causing resets and failed association. Use a short, thick cable and add a local bulk capacitor on 5 V or 3.3 V near the module. [Elektroda, kaczakat, post #17998944]

Could my board be a bad clone or faulty ESP32 module?

Yes. Many WEMOS‑style ESP32 boards are non‑Espressif clones with weaker power design. Compare against an official ESP‑WROOM‑32 reference board. If the clone misbehaves while a reference board works, suspect the module. [Elektroda, khoam, post #18002606]

What’s a safe retry pattern for Wi‑Fi without freezing my sketch?

Avoid blocking while loops. Periodically check connection status in loop(), and call WiFi.begin() only when disconnected. Add backoff between attempts and log status codes. This mirrors the forum fix of moving logic into loop with retries. [Elektroda, Anonymous, post #18002847]

It connects only once when cold, then fails—what does that indicate?

That pattern was observed: “Always the first one when it is cold.” It suggests marginal hardware or power sensitivity. Swap modules, test with a stable 5 V supply, and recheck antenna as AP. These isolate board versus environment. [Elektroda, Przybyłek, post #17998731]

How do I power the board correctly for Wi‑Fi tests?

Feed a regulated 5 V source into the board’s 5 V pin instead of a random USB port. Keep grounds solid and decouple near the module. Then retest association and DHCP to rule out power issues. [Elektroda, khoam, post #17998673]

Do core assignments in FreeRTOS affect Wi‑Fi stability?

Your Arduino loop runs on core 1, while the Wi‑Fi driver runs on core 0. Heavy work pinned to core 0 can hurt Wi‑Fi timing. Keep RF‑critical code non‑blocking. “WiFi stack execute on core 0.” [Elektroda, khoam, post #18003054]

How do I quickly check RF interference on my custom board?

Run the ESP32 as an AP and log RSSI on a phone while moving cables or turning peripherals on. Large RSSI dips near specific parts point to interference or poor antenna clearance. [Elektroda, khoam, post #17998747]

My code blocks on while(WiFi.status()!=WL_CONNECTED)—is that wrong?

Yes. Blocking prevents other tasks from running and masks timeouts. Add a connection timeout, then retry in loop() with delays or backoff. This simple change resolved repeated failures for a forum user. [Elektroda, Anonymous, post #18002847]

What differences between ESP‑WROOM‑32 and ESP‑32S matter for connectivity?

Original ESP‑WROOM‑32 modules follow Espressif’s RF and power guidelines and carry certifications. ESP‑32S and clones can vary in antenna and power components. Prefer documented originals for RF‑critical builds. [Elektroda, khoam, post #18002606]

How much current headroom and decoupling does ESP32 Wi‑Fi need?

Design for >=500 mA available on the 3.3 V rail to handle Wi‑Fi current transients. Place 10 µF bulk and 0.1 µF ceramic decouplers close to the ESP32 power pins with a low‑impedance ground. This prevents association brownouts. [“ESP32 Hardware Design Guidelines”]

Generated by the language model.