Strange output on serial port when reset ESP

[tomaszmacnar]

Basic Infos

Hardware

Hardware: ESP-07
Core Version: 2.3.0

Description

When upload any program (for example Blink) I have output (like in screen) on serial port. I need to have clean console. How to fix it ?

Settings in IDE

Module: Generic ESP8266 Module
Flash Size: 1MB
CPU Frequency: 80Mhz
Flash Mode: DIO
Flash Frequency: 40Mhz
Upload Using: no_ide_how_it_check
Reset Method: ck

[lrmoreno007]

It is normal in ESP8266 and is independent of the framework you use. Espressif says it can not be disabled.

But you should connect GPIO15 as TX and GPIO13 as RX and swap the default pins after the boot. You should not receive the garbage.
void setup() {
// initialize serial:
Serial.begin(115200);
// swap UART pins
Serial.swap();
}

Another option may be to transmit with Serial1 (GPIO2) and receive with Serial (GPIO3).
void setup() {
Serial.begin(115200);
Serial1.begin(115200);
}

Serial1.println();
Serial1.write();
Serial1.printf();
.......
Serial.available();
Serial.read();
Serial.readString();
......

Serial1 should not transmit the initial garbage. I can't try it today.

Another option (not good) use SoftwareSerial library for ESP8266 and any other pin available.

[tomaszmacnar]

Thanks for answear. I will check this solutions soon :)

[davisonja]

For completeness: It's a start up message from the espressif bootloader and is at 74880 baud. Or the baud rate set for a soft reset (as opposed to a power cycle) On 15/03/2017 7:26 pm, "tomaszmacnar" <notifications@github.com> wrote: Thanks for answear. I will check this solutions soon :) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#3047 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAN_AwNHtLo8aj2_JfLnozOsOOGRMrHfks5rl4ScgaJpZM4MdLz4> .

[lrmoreno007]

No, it's a boot log from the ROM. For that reason Espressif can't deactivate it, at least that's what they say.

[davisonja]

Yes, the ROM bootloader. Which, among other things, outputs log information on the reset cause and the boot mode.

https://github.com/espressif/esptool/wiki/ESP8266-Boot-ROM-Log

covers it.

[devyte]

Those messages can't be avoided on the main serial port. If you need a clean startup, please follow the suggestions above.
Closing.

[SergiuToporjinschi]

That is a serious problem. I spent a week debugging a circuit of a DHT and ESP8266-01 and because I was using GPIO2 (which is also a serial TXD1) and the esp is throwing this boot message on all Serials it seems. So, on ESP8266-01 only one pin available, and that is GPIO-0