"flash read err, 1000" on custom ESP PICO D4 board

[diyoio]

Hello,

I made a custom PCB following schematics of the ESP PICO D4 datasheet, made it printed and assembled by JLCPCB and I just received it but there is a problem.

When I connect my board UART to my computer I receive this continiously :

Code: Select all

17:48:47.012 -> rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
17:48:47.012 -> flash read err, 1000
17:48:47.046 -> ets_⸮⸮⸮⸮⸮⸮
17:48:47.385 -> 
17:48:47.385 -> rst:0x10 (⸮⸮⸮⸮⸮⸮-⸮⸮⸮⸮⸮⸮⸮⸮⸮⸮⸮?⸮⸮⸮P*⸮%==Q⸮
17:48:47.385 -> flash read err, 1000
17:48:47.385 -> ets_main.c 371 
17:48:47.385 -> 
17:48:47.757 -> rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASHGBGOT)
17:48:47.757 -> flash read err, 1000
17:48:47.757 -> ets_main.c 371 
17:48:47.791 -> 

When I press my BOOT button (putting GPIO0 LOW), the receive message change to :

Code: Select all

17:57:13.830 -> rst:0x10 (RTCWDTORTCORESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))
17:57:13.830 -> waiting for download

but then I receive a continous flow of 0x00 and I can't transfer my program...

Do you have any idea of the issue ?

Thanks.

[chegewara]

First logs usually means there is nothing flashed yet. So you need to flash some app to it.

Second logs means device is awaiting you flash something to it.

[ESP_Angus]

As Chegewara says, the first message is normal for a chip trying to boot from empty flash (embedded flash in this case).

but then I receive a continous flow of 0x00 and I can't transfer my program...

There shouldn't be any output after the output you've received. Can you confirm with a logic analyzer that it's actually outputting a correctly formed serial stream of 0x00 bytes? Is it possible there is some assembly issue which is causing noise on the UART RX or TX?