[GH-ISSUE #132] No/Gibberish serial output on Olimex MOD-WIFI-ESP8266 #100

New issue

Closed

opened 2026-02-28 01:23:25 +03:00 by kerem · 3 comments

kerem commented

2026-02-28 01:23:25 +03:00

Owner

Originally created by @codmpm on GitHub (Mar 21, 2016).
Original GitHub issue: https://github.com/tzapu/WiFiManager/issues/132

Hi tzapu,

just found WiFiManager and it is exactly what I need - great work! Sadly I ran into problems when using the MOD-WIFI-ESP8266-DEV from Olimex. I can't get serial output to work. All I see is something like this: "�n��#�n��r" at 115200 Baud. When I switch to 74880 Baud I get this output:

ets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 1264, room 16 
tail 0
chksum 0x42
csum 0x42
~ld

...looks like the bootloader. rst cause:2 is correct, as I used the attached reset button. boot mode:(3,6) seems correct, as 3 indicates boot from flash.

I've tested my code on the Adafruit Huuza-Board to double check and I get serial output as expected. WiFiManager itself runs on the Olimex-board as I see the AP and get redirected to the captive portal.

The Adafruit Board is using a Level-Shifter for the serial output. It get's powered with 5V from my Foca FTDI Adapter which works fine. The Olimex-board gets powered from the same Foca FTDI Adapter with 3.3V. It has switchable voltage and if I don't use WiFiManager I can get serial output as expected from the Olimex board.

Do you have any idea what I can do to get this fixed? Should get in contact with the Olimex support?

Thank you,
Patrik

Originally created by @codmpm on GitHub (Mar 21, 2016). Original GitHub issue: https://github.com/tzapu/WiFiManager/issues/132 Hi tzapu, just found WiFiManager and it is exactly what I need - great work! Sadly I ran into problems when using the [MOD-WIFI-ESP8266-DEV](https://www.olimex.com/Products/IoT/MOD-WIFI-ESP8266-DEV/open-source-hardware) from Olimex. I can't get serial output to work. All I see is something like this: "�n��#�n��r" at 115200 Baud. When I switch to 74880 Baud I get this output: ``` ets Jan 8 2013,rst cause:2, boot mode:(3,6) load 0x4010f000, len 1264, room 16 tail 0 chksum 0x42 csum 0x42 ~ld ``` ...looks like the bootloader. `rst cause:2` is correct, as I used the attached reset button. `boot mode:(3,6)` seems correct, as `3` indicates boot from flash. I've tested my code on the [Adafruit Huuza-Board](https://www.adafruit.com/products/2471) to double check and I get serial output as expected. WiFiManager itself runs on the Olimex-board as I see the AP and get redirected to the captive portal. The Adafruit Board is using a Level-Shifter for the serial output. It get's powered with 5V from my Foca FTDI Adapter which works fine. The Olimex-board gets powered from the same Foca FTDI Adapter with 3.3V. It has switchable voltage and if I don't use WiFiManager I can get serial output as expected from the Olimex board. Do you have any idea what I can do to get this fixed? Should get in contact with the Olimex support? Thank you, Patrik

kerem closed this issue

2026-02-28 01:23:25 +03:00

kerem commented

2026-02-28 01:23:26 +03:00

Author

Owner

@tzapu commented on GitHub (Mar 22, 2016):

hi, that looks like the boot loader messages that are supported only at 74880.
and then nothing from your sketch.
do you have serial begin in your sketch before wifi manager? does this happen to any example provided? how about some esp8266 examples?

@tzapu commented on GitHub (Mar 22, 2016): hi, that looks like the boot loader messages that are supported only at 74880. and then nothing from your sketch. do you have serial begin in your sketch before wifi manager? does this happen to any example provided? how about some esp8266 examples?

kerem commented

2026-02-28 01:23:26 +03:00

Author

Owner

@codmpm commented on GitHub (Mar 22, 2016):

Hi tzapu,

thanks for your fast reply. I'm using the AutoConnectWithFeedbackLED example without any modifications.

void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
//...
}

The exact same code works on the Huzza-board. The only difference is the board definition: (http://arduino.esp8266.com/stable/package_esp8266com_index.json), as I use the appropriate ones for the Huzza- or the Olimex-board.

Other examples using serial work. Only if I use WiFiManager there is no/gibberish output.

Thnx,
Patrik

@codmpm commented on GitHub (Mar 22, 2016): Hi tzapu, thanks for your fast reply. I'm using the [AutoConnectWithFeedbackLED](https://github.com/tzapu/WiFiManager/tree/master/examples/AutoConnectWithFeedbackLED) example without any modifications. ``` void setup() { // put your setup code here, to run once: Serial.begin(115200); //... } ``` The exact same code works on the Huzza-board. The only difference is the board definition: (http://arduino.esp8266.com/stable/package_esp8266com_index.json), as I use the appropriate ones for the Huzza- or the Olimex-board. Other examples using serial work. Only if I use WiFiManager there is no/gibberish output. Thnx, Patrik

kerem commented

2026-02-28 01:23:26 +03:00

Author

Owner

@tzapu commented on GitHub (May 8, 2016):

hi,

i don t have an olimex board to test unfortunately, i am not sure what could be different.

if you use generic board with appropiate settings, does it still happen?

@tzapu commented on GitHub (May 8, 2016): hi, i don t have an olimex board to test unfortunately, i am not sure what could be different. if you use generic board with appropiate settings, does it still happen?