ESP8266 Community Forum

- Wed Aug 19, 2015 3:32 am #26448 i have a problem with the serial receive from the ESP8266 modul.
When i want to receive anything from the serial port with a easy testprogram, the ESP make a reset and give the message below.

Here is the testprogram:

Code: Select allint incomingByte = 0;   

void setup() {
        Serial.begin(115200); 
}

void loop() {

                incomingByte = Serial.read();
                delay(1000);               
                Serial.print("I received: ");
                Serial.println(incomingByte, DEC);
}


And here is the message from ESP8266

Code: Select all ets Jan  8 2013,rst cause:4, boot mode:(3,7)

wdt reset
load 0x40100000, len 28976, room 16
tail 0
chksum 0x2f
load 0x3ffe8000, len 2404, room 8
tail 12
chksum 0x05
ho 0 tail 12 room 4
load 0x3ffe8970, len 1564, room 12
tail 0
chksum 0x5f
csum 0x5f
rl


I hope anyone have an idea about this problem

Markus

- Wed Aug 19, 2015 4:38 am #26449 Tried your sketch on a NodeMCU 1.0 (black) board, works as expected:

Code: Select allI received: -1
I received: -1
I received: -1
I received: -1
I received: 13
I received: 10
I received: 13
I received: 10
I received: 115
I received: 100
I received: 102
I received: 13
I received: 10
I received: 13
I received: 10
I received: -1
I received: -1


Perhaps you have some wiring issue?

- Wed Aug 19, 2015 7:33 am #26456 Thank you for your reply,

i have tested my wiring by flashing the AT Firmware... and it works.
The ESP accept the commands and give OKs return.
I have only the problem with the arduino ide.
I have tried another usb serial adapter, the same problem.
And i have swapped the serial port and use the pins 13 and 15 for testing.
I connected one USB converter at pin 13+15 and another at 1 +3 and have the result that at pin 13+15 the string came:
I received: -1
I received: -1
I received: -1
... and so on
and when i type anything the ESP make a reset and at pin 1+3 come the message:
ets Jan 8 2013,rst cause:4, boot mode:(3,7)

wdt reset
load 0x40100000, len 28976, room 16
tail 0
chksum 0x2f
load 0x3ffe8000, len 2404, room 8
tail 12
chksum 0x05
ho 0 tail 12 room 4
load 0x3ffe8970, len 1564, room 12
tail 0
chksum 0x5f
csum 0x5f
rl


And after that on pin 13+15 come the string
I received: -1
I received: -1
I received: -1

And so on.

I haven't any idea whats happened

- Wed Aug 19, 2015 9:21 am #26474 Change your loop() for something like that (notice that I reduced the delay and moved it outside of the while(), and the available() will prevent displaying the "-1") :

Code: Select allvoid loop() {
    while(Serial.available())
        incomingByte = Serial.read();
        Serial.print("I received: ");
        Serial.println(incomingByte, DEC);
    }
    delay(100);               
}