Hi, I experienced some troubles with the esp8266-01 wifi module. Firstly i encountered this guide: https://www.instructables.com/id/Getting-Started-With-the-ESP8266-ESP-01/
The interesting thing is a guy here doesnt use any voltage divider when connecting his TX RX pins to arduino. I tried do everything his way but it didnt work. After i already tried that I read that u should lower the volatege of those pins or u can damage your esp. I tried a lot of different setups with voltage dividers, additional resistors, but nothing worked. Also most guides I read suggested connecting RX from arduino to TX from esp and TX to RX. Finally i could get a response to AT commands by pinning TX to TX and RX to RX without voltage divider, not connecting the reset pin at all and by setting baud rate on arduino IDE to 115200. I had some doubts because when i opened the serial monitor i firstly had some unidentified character (something you could experience when choosing a bad baund rate) but after writting first command it was fine, tho sometimes a command would just not work and i would get an error messege but then rewriting the command would make it work. the thing is i tried to upload a program but it didnt. i tried to flash the esp with new firmware, after it finished i was able to upload a program but the AT command no longer gave any response. Can someone tell me what is the proper wiring to ESP via arduino, and why the 5V tx rx pins worked but after i divided voltage to 3.3V it didnt. Also what should i do to make the AT commands work again? Thanks in advance.
In many cases, I have successfully operated (NodeMCU 1.0(ESP-12E) and UNO in direct connection (withiut voltage divider circuit) for UART and I2C operations.
I opened the serial monitor, plugged the reset pin to the ground, and i noticed that if i disconnected the reset pin from ground i would get some unknown characters in the serial monitor. I tried that at different baud rate, and finally at 74880 baud rate i got a message saying
17:10:44.517 -> ets Jan 8 2013,rst cause:2, boot mode:(3,7)
17:10:44.517 ->
17:10:44.517 -> load 0x40100000, len 2592, room 16
17:10:44.564 -> tail 0
17:10:44.564 -> chksum 0xf3
17:10:44.564 -> load 0x3ffe8000, len 764, room 8
17:10:44.564 -> tail 4
17:10:44.564 -> chksum 0x92
17:10:44.564 -> load 0x3ffe82fc, len 676, room 4
17:10:44.564 -> tail 0
17:10:44.564 -> chksum 0x22
17:10:44.564 -> csum 0x22
17:10:44.564 ->
17:10:44.564 -> 2nd boot version : 1.7(5d6f877)
17:10:44.564 -> SPI Speed : 40MHz
17:10:44.564 -> SPI Mode : QIO
17:10:44.564 -> SPI Flash Size & Map: 8Mbit(512KB+512KB)
17:10:44.564 -> jump to run user2 @ 81000
17:10:44.564 ->
17:10:44.564 -> error magic!
17:10:44.564 -> backup boot failed.
17:10:44.564 ->
17:10:44.564 -> user code done
I also tried At commands at this rate but it wouldnt work ( kinda obvious, but still wanted to try). Do you happen to know what should i do? i dont really understand that error messege besides that something went wrong
I successfully flashed the ESP once again carefully checking the addresses, the AT commends work fine now, still every time i open serial monitor the first message i get is bugged, but then it is good
Krulicusek:
I successfully flashed the ESP once again carefully checking the addresses, the AT commends work fine now, still every time i open serial monitor the first message i get is bugged, but then it is good
The same things happens for my NodeMCU 1.0 9ESP-12E) whose pictorial view is given below. For my ESP, there is no option to GND the reset pin.
Please, post a picture of the ESP variant you are using.
I'm using the ESP 01 module. Currently neither flashing with new firmware works, nor uploading program towards arduino IDE.