I have solved it (with my Prof. help), writing a batch file and launching it directly from /tmp directory of my Raspberry (instead of PC)
This is the batch file content, that help me to avoid the flash error:
voice_esptool --chip esp32 --port /dev/ttyS0 --baud 115200 --before default_reset --after hard_reset write_flash -u --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader/bootloader.bin 0x10000 mic_energy.bin 0x8000 partitions_singleapp.bin
I have another big problem for develop my university project; it consists in a little system (c++ code) that acquires music and sounds, from the environment, and trasform them into colors. My hardware is composed by Raspberry Pi 3 + DMX module for Raspberry Pi 3 + LED unit + Matrix Voice esp32. My Raspberry’s GPIO is occupied by the DMX module so for that reason I recurred to Matrix Voice esp32. The problem is how can my Matrix Voice esp32 send via wi-fi audio stream (environmental sounds or music) in real time to my Raspberry Pi? Do you have a sample code in C++ for that? I got this link from Kevin https://github.com/Romkabouter/Matrix-Voice-ESP32-MQTT-Audio-Streamer, the main problem is that my background is in economics, I’m a newbie in coding, and this code is created for arduino - esp32 communication (and viceversa) instead I need c++ code raspberry - esp32 (and viceversa).
Any other suggestion or solution is welcome!
P.s. I’m going to post this code in https://github.com/matrix-io/matrixio_hal_esp32