Problem with ESP8266 Thing Serial Communications

Wireless & IoT
1

I am using the ESP8266 Thing with the Arduino 1.6.4 IDE. I have encounter two issues.

The first is this warning received when I first start the IDE with the Sparkfun Thing as the board:

WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library
WARNING: Spurious .git folder in 'Phant' library

The second is when I try to use the Serial Communications. I am using the Sparkfun FTDI Basic (3.3 volt) with the ESP8266 Thing to provided the serial communications. When I connect to the ESP8266 Thing to any communications program (Arduino Serial Monitor, or Micrcom), the ESP8266 Thing stops. Here is the modified blink code that I am testing:

#define ESP8266_LED 5

void setup() 
{
  pinMode(ESP8266_LED, OUTPUT);
  Serial.begin(9600);
}

void loop() 
{
  digitalWrite(ESP8266_LED, HIGH);
  delay(500);
  digitalWrite(ESP8266_LED, LOW);
  delay(500);
  Serial.println("It blinked");
}

Is the serial connection starting the boot loader and stopping the current program? If it is then how does one use the serial connection to allow debugging? Thank you in advance for any help on this.

If this is posted in the wrong forum area, then I apologize for the error and please move it to correct one.

2

I get the same warning plus a warning about the Adafruit NeoPixel library as well. It’s weird because several other libraries have git folders and it doesn’t complain about them. It seems to work just fine in spite of the warning.

For the serial communications issue: Did you work through the Hookup Guide? Take a look at the section called Using the Serial Monitor:

To make it easy to program the ESP8266, we’ve tied GPIO0 to DTR (along with RST). When your programmer begins to upload a sketch, it’ll pull DTR low, in turn setting GPIO0 low and making the ESP8266 enter bootloader mode.

Unfortunately, when you open a serial terminal, DTR usually goes low again. So every time you open the Arduino serial monitor, it’ll cause the ESP8266 to enter bootloader mode, instead of run-program mode. If you open up the serial monitor, and all you see is a line of gibberish, you’ve probably booted the ESP8266 into bootloader mode.

There's more detail in the Hookup Guide.
  • Chip
3

Thank you, Chip for the information. Yes, I did go through the Hookup Guide. I missed the section on the serial monitor. I assumed the ESP8266 program would have control the serial. I was wrong.

I did try two other USB to TTL serial converters, a common CP2102 based one and one marked AI. Both do not have a DTR connection. They both worked fine connected to serial port for debug. I will have to read the hookup guide more closely. I “grounded” the DTR pin to see if I could get the ESP8266 Thing to go into boot loader. Upon removing the ground connection to DTR, the ESP8266 Thing was reset and started the program, no boot loader. Back to the documentation or RTFM!

I do have a tip for other users. I normally use a “bat wing” bread board power supply for my experiments. Connecting the +5 volt output of the bread board power supply to the ESP8266 Thing VIN pin will allow it to work. The power on/off switch works normally. This does not require another USB connection. However, the battery charger will not work.

Thanks for the help.

Edit for other readers: After reading the section of the serial monitor, I found that pulling Pin 0 low will place the ESP8266 Thing into boot loader mode. The information is in the section, Using the Arduino Addon.