ESP8266: Unknown upload protocol esp-prog

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1

I am trying to move my ESP8266 project over to a custom PCB. I just received the first version. The idea is to use Espressif’s Prog Board to upload to the ESP via serial connection.

The PCB is based on the wroom2 module, so I assume that’s what I’d have to select as board? I have this very simple PlatfromIO ini file:

[env:esp_wroom_02]
platform = espressif8266
board = esp_wroom_02
framework = arduino
debug_tool = esp-prog
upload_protocol = esp-prog

However when I try to upload, I get a warning saying

Warning! Unknown upload protocol esp-prog

After successfully compiling my code, nothing happens. It looks like it doesn’t even try to upload the code.

Can anybody provide any inside on what I have to do to get the esp prog recognized by platform io?

2

Per Espressif ESP-WROOM-02 — PlatformIO latest documentation there is only support for esptool and espota.

I only know the ESP-PROG in relation to the ESP32, but not to the ESP8266.
However, it should be possible to use it as a simple USB to serial bridge.

The setting for this is then esptool.

3

Thanks for the answer. I was going by this statement:

ESP-Prog’s automatic firmware downloading and serial communication functions are supported on both the ESP8266 and ESP32 platforms

From the ESP Prog site of the platform io docs here: ESP-Prog — PlatformIO v6.1 documentation

But if I understand you correctly, as long as I’m not using the JTAG stuff, the upload protocol would be esptool even if I’m using the prog board? I’ll give that a try.

4

Yes, thats correct.

You only use the USB to Serial feature of the ESP-PROG. Same as a FTDI cable or CH3xx Chip on devkit modules.

AFAIK the ESP8266 lacks the JTAG feature.

5

Remove those two lines if you want to upload via serial. That’s the regular esptool protocol then. Also, PlatformIO doesn’t support JTAG-debugging the esp8266 via the ESP-Prog (https://github.com/platformio/platform-espressif8266/issues/280), and debugging via a gdbstub is also highly experimental (https://github.com/platformio/platform-espressif8266/issues/43) and unstable.

6

Okay, thanks everyone, I got that working now. I simply didn’t understand that not all ways to use the esp prog board require the esp-prog upload protocol.

Unfortunately there’s still something wrong with my connection. After being able to upload a very simple project a couple of times in a row, I then never got it to work anymore. I’ve been trying to fix this for a couple of hours now, but the farthest I get is either this error:

“A fatal error occurred: Timed out waiting for packet header” right after it is saying “Uploading stub…” or sometimes it does start to copy but then stops after 20 or 30% and just times out.

I’ve tried various different baud rates, connecting the prog board and the PCB to power as I thought maybe I don’t have enough power, tried different USB ports on my Mac, manually putting it in boot mode,… nothing.

7

Never mind, finally got this working. After trying the third USB cable I thought I ruled out an issue with the USB cable, but apparently the forth cable fixed it and the connection is rock solid now!