As I am learning the Arduino coding, I want to see if my program can turn on the LED light. I have tried all the things, but the code does not start the LED light I have installed on the board.

The code compiles successfully and upload on the board, but nothings happens after that. See the output logs as below:

See all the configuration of board as below:

The board I have: UNO+WiFi R3 ATmega328P+ESP8266 CH340G Board compatible with Arduino


Board switch settings:

5,6,7 => ON (to upload the code from Arduino IDE)

Yellow LED installed:

13 => Positive, GND => Negative

Board setup:

enter image description here

Arduino IDE Setup:

enter image description here


void setup()
  pinMode(13, OUTPUT);

void loop()
  digitalWrite(13, HIGH);
  digitalWrite(13, LOW);

Output logs after uploading the code:

esptool.py v2.8
Serial port COM8
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: ec:fa:bc:3e:2e:6f
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x0340
Compressed 261472 bytes to 193134...
Wrote 261472 bytes (193134 compressed) at 0x00000000 in 17.1 seconds (effective 122.1 kbit/s)...
Hash of data verified.

Hard resetting via RTS pin...

As you can see, the last message is Hard resetting via RTS pin....

Would anyone please tell me what is happening here? Why the program does not start the LED light even after everything looks fine?

Any help would be greatly appreciated.


  • switch the DIP switches to ATmega328p, set Uno in Tools menu and upload the Blink sketch. the esp8266 is there as a network adapter, not as a main MCU of the board
    – Juraj
    Apr 10, 2021 at 8:52
  • Thank you @Juraj. It is working now. Please put this comment as a answer and I will mark a an accepted answer. Thank again.. You made it. Apr 10, 2021 at 9:36
  • that is all? this was the problem?
    – Juraj
    Apr 10, 2021 at 11:15
  • Yes @Juraj. That was the only issue. Thanks very much. Apr 10, 2021 at 11:21
  • Related, if not about the same thing: arduino.stackexchange.com/questions/83377/…
    – chrisl
    Apr 10, 2021 at 14:47

1 Answer 1


The Uno+WiFi board is an Uno. With DIP switches 3 and 4 in ON position it is a normal Arduino Uno clone with CH340 chip for USB. All the pin headers at board sides and the ICSP pins are as on an Arduino Uno. Every sketch for Uno will work.

The esp8266 is added for WiFi functionality. The DIP switches allow to program the esp8266 over the CH340 or to connect the esp8226 to Serial of the Uno part (ATmega328p).

To have Serial free for USB, it is usual to wire the esp8266 to a common Uno on some other pair of pins then RX/TX and use SoftwareSerial. There is no such connection on this Uno+WiFi, but the esp8266 header has the Rx/RX pins of the esp8266 so it is possible to wire SoftwareSerial pins with jumper wires (power and ground are connected on board of course).

enter image description here

Don't switch the DIP switches too frequently. They are not made for it and fall apart. Upload some permanent firmware to esp8266 or use OTA upload for esp8266.

  • Thanks for the answers. What would be the DIP switch settings if I want to run Arduino UNO clone with CH340 + Wifi functionality. (Wifi is already on board). What would be the switch settings for both to work together? so that I can create a program to read the data from internet and display on LED panel. Please suggest. Apr 10, 2021 at 12:21
  • you should not use switches 1+2 and 3+4 at same time so you can set 3+4 for 'Uno' and put two wires between the RX/TX of esp8266 and a pair of Uno pins and use SoftwareSerial on that pins
    – Juraj
    Apr 10, 2021 at 12:37
  • Thanks, but not getting it right as I am beginner and not sure how to do that. Any information on how to do that would be greatly appreciated. Apr 10, 2021 at 12:45
  • the Internet has many tutorials how to connect an esp8266 module to Uno. now you know how to apply them to Uno+WiFi
    – Juraj
    Apr 10, 2021 at 13:15

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