ESP8266 Community Forum

Hello, how are you?

I currently have a project that I would like to replace the USB connection with Wi-Fi connection. With the USB connection, once you plug it to the computer, a new COM port is listed and then the windows software can communicate with it using RS232, so sending usigned char (ranging from 0 to 255) byte arrays is very easy. It uses a PIC24F with USB module, so everything is pretty straightforward.

I bought a few ESP8266 modules and I have been playing around with it. I would like to ask you to please point me to the right direction of which way would be best for this data intensive application, that I need to be constantly sending and receiving data?

It needs to leave an "open bridge", for example, once it is connected, I can transfer data without having to send HTTP headers eve

1) Is it possible that I can transfer data without having to send HTTP headers every time? An "open bridge" sort of thing. Correct if I'm wrong, but I think to do that I should use TCP or UDP protocol? Where do I get started? Reading material is very welcome.

2) Is it possible to transfer arrays of bytes ranging from 0 to 255? I tried transfering bytes after the HTTP headers, but of they were 0 or bigger than 127, it would get stuck, because it violates text encoding rules I suppose.

3) What kind of speed in KB/s can I expect? With the USB I transfer chunks of 128 Bytes quickly. The full EEPROM is 32 KB.

4) Should I code ESP8266 chip from scratch or is there a way to use something like the AT command, Nodemcu or what?

Any advice will be highly appreciated.

Thank you!

Fernando

There is "esp-link" project that do exactly that, it is a serial bridge that let you communicate thru Wifi.
https://github.com/jeelabs/esp-link

Hi Martinayotte, how are you?

That is awesome, this appears to be exactly what I need. However, I am having a problem to flash using NODEMCU programming tool. It works fine with ESP8266 Flasher, but that one doesn't allow to select 3 the three different files required for the esp-link project.

My USB -> Uart adaptor is 115200 Bps and has TX / RX lines. GPIO 0 is pulled to the ground. I believe that memory configuration on nodemcu flasher is correct, still, no result. it is always stuck with the "Begin find esp8266" message. Any ideas? Here's a video:

https://youtu.be/El6X0a7XMM4

If you install python along with pyserial, you can use esptool.py from https://github.com/themadinventor/espto ... esptool.py
You can use it to upload several files at the same time with their respective offset like :

esptool.py --port /dev/ttyUSB1 write_flash 0x00000 file1.bin 0x40000 file2.bin