Flashing ESP32 without buttons? (CTS RTS at uart dongle)

[newsettler_AI]

Hi,

I have ESP32-Core-board-v2 kit and FTDI uart converter.


How can I use RTS and CTS pins to automatize a little flashing process? I want esp can enter in boot mode via remote access (let say, I leaved it in one place and can reflash it from another place).

I have read that this was possible with ESP8266, but not sure about ESP32.

Please advice.

[ESP_Sprite]

With the core board, you mean this one?

The core board already should have functionality for this on board: if you hook it up over USB and use esptool.py by for example, it should automatically go into download mode. No need to use an external FTDI chip; the board already has an internal USB to serial converter.

[newsettler_AI]

Yes, this is my ESP32 board.

I'm using Eclipse and when I'm trying load projects, I need firstly hold BOOT and then restart module (press EN). ESP runs in boot-mode.
Overwise eslipse cant load firmware.

Should I edit esptool.py or change something in eclipse settings?

[ESP_krzychb]

Adding a 2.2uF capacitor between EN and GND resolved similar issue for me. https://github.com/espressif/esptool/is ... -257033484

[newsettler_AI]

Well, I'm dont have such capasitor onhand right now, I will try it later.

Aslo, I noticed, that there is one more solution in topic - changing time.sleep() to 0.5 in line 352.
I tried, by Eclipse says:

File "D:/ESP32/esp-idf/components/esptool_py/esptool/esptool.py", line 352
time.sleep(0.5)
^
IndentationError: unexpected indent
make[1]: *** [/d/ESP32/esp-idf/components/esptool_py/Makefile.projbuild:49: /d/ESP32/Project_1/build/bootloader/bootloader.bin] Error 1
make: *** [/d/ESP32/esp-idf/components/bootloader/Makefile.projbuild:31: /d/ESP32/Project_1/build/bootloader/bootloader.bin] Error 2

[ESP_Angus]

Well, I'm dont have such capasitor onhand right now, I will try it later.

If you have any capacitor with a similar value (approx 0.5uF-4.7uF range), it will probably have the same effect.

Can you please share what version of the Core Board (it's written on the bottom if it's an Espressif one) and what OS you are using?

Aslo, I noticed, that there is one more solution in topic - changing time.sleep() to 0.5 in line 352.
I tried, by Eclipse says:

File "D:/ESP32/esp-idf/components/esptool_py/esptool/esptool.py", line 352
time.sleep(0.5)
^
IndentationError: unexpected indent
make[1]: *** [/d/ESP32/esp-idf/components/esptool_py/Makefile.projbuild:49: /d/ESP32/Project_1/build/bootloader/bootloader.bin] Error 1
make: *** [/d/ESP32/esp-idf/components/bootloader/Makefile.projbuild:31: /d/ESP32/Project_1/build/bootloader/bootloader.bin] Error 2

Python uses whitespace for program structure, so you need to indent with spaces (not tabs) to the same depth as the surrounding code.

I don't think this time.sleep(0.5) will fix the problem you're seeing, timing-related fixes have already been incorporated into esptool v2.1.. If it does fix the problem, please let us know.

[newsettler_AI]

Hi, sorry for late delay with answer.

Recently I got new esp core board and it flashing automaticaly without issues.

But now I'm interesting, is it possible to flash automatically bare ESP-WROOM-32 module using only CTS and RTS pins?
I have checked schematic of coreboard.
https://dl.espressif.com/dl/schematics/ ... V2_sch.pdf
Looks like EN_pin and IO_0_pin connected through some transistors. Is there way can I avoide adding this components to be able to flash WROOM module automatically?

This is module that I'm talking about:

[luisfelipemiranda80]

FTDI -> ESP WROOM 32
RTS -> EN
DTR -> GPIO 0
GND -> GND
VCC (3.3) -> 3.3V
TX -> RX0
RX -> TX0