Fatal error while uploading sketch to A16

[tanoshimi]

Hi,  I recently bought a KC868-A16 board but am unable to use it, since I receive a fatal error when attempting to upload any new sketches onto it

I'm using the Arduino IDE v2.0.4, targetting the "NodeMCU-32s" board from the esp32 boards definitions (v2.0.7). This is the error I receive when attempting to upload any sketch:

Code:

Sketch uses 292297 bytes (22%) of program storage space. Maximum is 1310720 bytes.
Global variables use 25300 bytes (7%) of dynamic memory, leaving 302380 bytes for local variables. Maximum is 327680 bytes.
esptool.py v4.5.1
Serial port COM7
Connecting....
Chip is ESP32-D0WD-V3 (revision v3.0)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 90:38:0c:a4:38:94
Uploading stub...
Running stub...
Stub running...
WARNING: Failed to communicate with the flash chip, read/write operations will fail. Try checking the chip connections or removing any other hardware connected to IOs.
Configuring flash size...
Flash will be erased from 0x00001000 to 0x00005fff...
Flash will be erased from 0x00008000 to 0x00008fff...
Flash will be erased from 0x0000e000 to 0x0000ffff...
Flash will be erased from 0x00010000 to 0x00057fff...
Compressed 17520 bytes to 12170...
Writing at 0x00001000... (100 %)

A fatal error occurred: Serial data stream stopped: Possible serial noise or corruption.
Failed uploading: uploading error: exit status 2

There is not other hardware connected to the board. I am using the power supply and USB-C cable that it was supplied with (although I have also tried swapping these for other ones, and also tried different USB ports on my laptop).
As suggested elsewhere, I have tried reducing the upload speed from the default 921600 to 115200, but that made no difference.
The board itself seemed well-packed and doesn't show any obvious signs of damage, but I'm wondering if the chip is faulty, since the error appears to suggest a problem with the flash memory?

Hopefully you can advise! Thanks,

Alastair

[Philadam]

If you have the RF modules installed, try removing them. 
Had the same issue with KCS firmware and removing the RF modules solved my problem.

[admin]

yes, when download firmware with KC868-A16. remove the RF433 Module will be work fine.

[tanoshimi]

If you have the RF modules installed, try removing them. 
Had the same issue with KCS firmware and removing the RF modules solved my problem.

Thankyou! Yes, that seems to have fixed the issue.

So, that's because of the ESP32's specific requirements for pins 2/15 to be LOW/HIGH to enter flashing/boot mode, right? And having the RF modules connected to these pins prevents that.
That seems to be somewhat of a flaw in the A16 design, because when developing and testing any application that uses those components I have to keep on removing and replacing them every time I make a modification to the sketch?

If that's the case, I wonder what the purpose of the "DOWNLOAD" button on the board is? It doesn't seem to be documented anywhere. If it's required to get the chip to enter programming mode, could it also be used to disable those components during the upload process?

[admin]

That seems to be somewhat of a flaw in the A16 design, because when developing and testing any application that uses those components I have to keep on removing and replacing them every time I make a modification to the sketch?

--->>because the RF reciever module have pull up resistance will influence ESP32 chip download.

actually the "DOWNLOAD" button not need to use in our board, because we have designed auto download circuit on our board. so the "DOWNLOAD" button just GPIO0 of ESP32, you can use for your own function by your code.