simulink; Failed to connect to Arduino board, when using esp8266

Hi!

I just bought a esp8266 (https://www.reichelt.com/at/en/developer-boards-esp8266-wi-fi-module-debo-esp8266-p192142.html?&trstct=pos_0&nbc=1), to connect to my arduino Uno (Type elegoo Uno rev3).

I have connected the esp to my arduino uno, as documented in the datasheet for the esp. Then, I tried to use the simulink example code arduinomega2560_wifitcpsend, described in https://se.mathworks.com/help/supportpkg/arduino/ref/getting-started-with-wifi-on-arduino-hardware.html. I also changed the hardware, and from shield to esp8266, so this should not be a problem. When I tried to upload this to the arduino the first time, I got as an error that "Failed to assign IP address to ESP8266.", I then followed this matlab guide to try to fix the problem (exept the point of updating the firmware, I could not figure out how to do this) https://se.mathworks.com/help/supportpkg/arduino/ref/getting-started-with-wifi-on-arduino-hardware.html. I this example I had connected RX to RX and TX to TX though. So this was probably the problem? I have also tried the same example with another esp8266 (with the development board), but got the same problem.

But when having connected RX (pin 0 on arduino) to TX on the esp, and TX (pin 1) to RX of esp, I got the new error;

The following error occurred during deployment to your hardware board: Failed to connect to Arduino board. Verify connection and the host COM port number entered in 'Configuration Parameters > Target hardware resources > Host-board connection' and try again. To find out the COM port number in Windows, open Device Manager and open your board in the COM ports group.

I also just tried a small LED-circuit, where I sent a pulse from the arduino til pin 9, that then turned the LED on every second. When I run it, without the arduino being connected to the esp8266, this works. If the arduino and esp8266 are connected, on the other hand, I get the same error about not bein able to connect to the arduino board (and this is without having e.g. wifi-blocks in the led simulink code. It is only a pulse generator and a arduino pin-9 output)

I have also tried connecting both of the esp's through the arduino ide, but get similar problems about the system not bein able to find them/the com.

Could anyone help me? I am really lost, and have been trying to figure this out for a week. (edit; And I should use this in a project at school, that should be delivered in 8 days ahha, so I am a bit desperate <3) Thank you for reading!

[Thale]

I have now tested, with having RX at TX, TX at RX. And then taken out CH_PD once, then I get the "Failed to assign IP address to ESP8266.", error. I tried again, using all the connections as in the documentation, but taking out the GPIO0 connection. This time I also got "Failed to assign IP address to ESP8266.".

When I have all connections the same as in the documentation, I get the COM error. Could it be that the COM changes, when the arduino is connected to the external wifi module?

Also, when I did the arduino IDE example in the esp6288 documentation I got a connection error;

connecting........_____....._____....._____....._____....._____....._____.....____Traceback (most recent call last):

and then:

esptool.FatalError: Failed to connect to ESP8266: Timed out waiting for packet header

Answer 1

[Nathan Hardenberg]

A friend of mine had a similar problem. The problem is probably that you use the only serial interface (UART) of the Arduino UNO for the connection to you PC/Simulink automatically. Now you also want to use it to connect to th ESP. That does not work.

If you want to use UART/Serial with Simulink and also want to use it as other communication you most likely have to use the Arduino Mega, since it has more serial connections

https://www.arduino.cc/reference/en/language/functions/communication/serial/

Maybe you can just "build and run" the model and not "run & Tune", but I don't know if this works, since you also use the serial interface to write to the arduino