ESP8266 - flashing problem, not detected by nodemcu flasher and esptool

Hello,
as in the subject I have an ESP8266 module and I have a problem flashing it. I wanted to upload software to it to turn it into a transparent Wifi->RS232 bridge, as I need this for a project. Neither nodemcu flasher nor esptool detects it. The chip works because the "boot_mode" changes when connecting GPIO0 to GND (Putty at ESP diagnostic speed 74840):



When GPIO0 is not connected to GND, "normal boot" is seen. After several attempts the chip has already unfortunately probably cleared memory, as AT commands were working before and now "main.c" is probably empty. Speed and COM port settings correct commands worked the chip communicated at 115200 and at this speed I tried flashing. Diagnostic messages come in at 748400 speed. Strange thing because I have two such chips (0.5Mb blue version and 1Mb black version) and the same situation on both of them, also there is a mistake on my part somewhere. Any suggestions Fellows?

Connection:

VCC-> 3.3V
CH_PD-> Via 10k resistor 3.3V
Reset -> Via 10k 3.3V resistor
GPIO0 -> GND
GND-> GND
TX RX connected correctly via voltage divider for RX of module. Commands pass correctly communication worked fine.

I had a similar problem, supposedly the communication was there but the flashing wouldn't happen.
In my case it helped to change RS232 -> USB converter from Chinese FT232 to equally Chinese PL2303

Thanks for the reply, I will check on the PC where I have a COM port built in + MAX232. Greetings

Hello,
i had a problem like this, what helped was momentarily resetting the reset pin to GND. My ESP then changed the baud rate to 9600 for a few seconds, broadcasting basic info about the firmware it had uploaded. It was possible to start uploading firmware during this time. It went quickly through a program from Nodemcu with its own firmware selected from disk.
Later ESP worked normally with AT commands or with the Arduino IDE compiler.

I was successful with these settings oddly enough:





I only get the black version flashing at 26.7 MHz. Maybe someone will find this useful. Greetings

I have one more question about this Wifi <-> RS232 converter. Everything works as expected, but have any colleagues heard of any software to create a virtual COM port via telnet? For Bluetooth there is no problem because there are such.... At the moment communication works perfectly via RealTerm - Telnet connection.

Hello, I'm also using these modules and it's strange with the memories, i.e. one of the module's FLASH memories "crashed" after a few hundred software upload cycles (I've been writing various scripts and generally speaking "playing" with this little box) - at some point during one of those flashings the module went completely mad, it kept throwing errors, started resetting itself and only after I've soldered a clean flash on it did it go away... now I have the effect that the program works, but I can't upload anything new, ESPlorer says the module is busy (BUSY when I try to enter anything into the module) neither reset nor format helps nor uploading new firmware - so something strange is going on with these modules. Has anyone had a similar effect ?

Welcome,

gosztekseba wrote:

I have another question about this Wifi <-> RS232 converter. Everything works as expected, but have any colleagues heard of any software to create a virtual COM port via telnet? For Bluetooth there is no problem because there are such.... At the moment the communication works perfectly via RealTerm - Telnet connection.

Yes, there are many such programs (if I understand what you mean correctly). I at one time used HW VSP3 - Virtual Serial Port .

However, if you are using NodeMCU on the ESP side, then you can use a tool for direct file management over TCP/IP that I committed and called ESPresso .

otapi wrote:

I had a similar problem, supposedly communication was there and it wouldn't flash.

There are often various problems with flashing. Probably depends on the FTDI converter.

With me, for example, only flashing with esptool ver.1.1 with the following settings (they are in the esptool.py file) works:

In LUA ESP, you can create exactly as many virtual com ports as you have free GPIOs, the only problem can be the modest RAM into which you have to load, 8x256 character arrays, which can be deadly if there is something else ESP has to do. This is done using the function gpio.serout(nrgpio,{8bytesASCIIcharacterArray}), to which you should add the start, stop and possibly parity bits