Troubleshooting ESP8266-01 connection through Arduino Uno

Projects Networking, Protocols, and Devices
1

Hi,

I have connected an ESP8266-01 (see picture link one) with and Arduino Uno board. Trying to upload code or communicate with the ESP seems difficult.
ESP8266-01 picture:

The following has been done on the Hardware side:

  1. External power supply has been used to make sure I have 3,3VDC and greater than 200mA Current.
  2. Arduino Uno has connection between GND and RESET to enter passive mode. Is this correct?
  3. The ESP has a switch connected between the GPIO0 and ground and is powered connected to ground which should let me enter UART mode. When powered a red LED is constant high, when ground connection is disconnected the LED goes high. Is this correct?
  4. Arduino TX is directly connected to the ESP TX.
  5. Arduino RX is connected to the ESP RX with a voltage divider which consists of one 1kOhm resistor and one 1,8kOhm resistor. Since the RX has a 5V output this is now divided to about 3,2V (see picture link 2 & 3 for schematics and breadboard overview). First, I do not measure 3,2V between R1, R2 and GND, I measure 1,3V. I do however measure 3,6V between the RX output and GND which should still be 5,0V. Any idea why this happens?

Breadboard picture:

Schematic picture:

On the software side:

  1. I have put in the boards manager URL http://arduino.esp8266.com/stable/package_esp8266com_index.json
  2. I have added ESO8266 in board administration.
  3. Changed board to "Generic ESP8266 Module" (See parameters in picture link).
  4. I try to upload example program called ESP8266WebServer - Hello World and the following message is generated:
    warning: espcomm_sync failed
    error: espcomm_open failed
    error: espcomm_upload_mem failed
    error: espcomm_upload_mem failed

Setup picture:

Please help me both hardware and software responses will be honored.

Yours sincerely
ElPutino

2

ElPutino:
5) Arduino RX is connected to the ESP RX with a voltage divider which consists of one 1kOhm resistor and one 1,8kOhm resistor. Since the RX has a 5V output this is now divided to about 3,2V (see picture link 2 & 3 for schematics and breadboard overview). First, I do not measure 3,2V between R1, R2 and GND, I measure 1,3V. I do however measure 3,6V between the RX output and GND which should still be 5,0V. Any idea why this happens?

The Arduino already has a 1k resistor on the RX pin (i.e. TX pin of ATmega16U2). Remove your external 1k resistor, but leave your 1.8k resistor. Also keep in mind that you have to reset the ESP while pressing the button on GPIO0.

Pieter

3

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