Custom PCB startup problem

[Zeni241]

I am facing startup problem with my custom board. If the supply voltage is more than 3.3V then the board ‎always boot in download mode and I get following lines in terminal:‎
rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))‎
waiting for download
If the supply voltage is 3.3v than the board will boot in normal mode and the message in terminal is:‎
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)‎
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00‎
mode:DIO, clock div:2‎
I am following ESP32_DevKitC_SCH_20180607A for my custom board.‎
I want the board to boot in normal mode till I keep pressing button which connects IO_0 to GND.‎
I am using ESP32EU module on my board

[ESP_Sprite]

Can you share your schematic? Even if you say it's according to the DevkitC, we'd still like to check.

[Zeni241]

Thanks for your response. Bellow is my schematic. I am also attaching the DevKitC-Ver4 schematic I am following. I have searched the web and tried many solutions but of no use.

Schematic_Zeni2412.jpg (417.87 KiB) Viewed 2574 times

ESP32-DevKitC-V4_SCH_20180607A.jpg (1.14 MiB) Viewed 2574 times

[Zeni241]

I am suspicious of C12, C13 , 100nF capacitors attached to EN and IO_0 pins

[ESP_Sprite]

I think your issue is that the RC network on the EN line charges at a faster rate as the RC network formed by C12 and the internal pullup resistance. Suggest getting rid of C12; the equivalent capacitor C15 is marked as NC on the ESP32 devkit schematic indicating there's a footprint for it but by default it's not fitted. (So your suspicion was correct.)

[boarchuz]

Also ME6217's enable pin is floating.

[Zeni241]

Wow!!! Its working now . Thanks a lot 'ESP-Sprite", removing C12 (connected with IO_0) solved the problem.

Also "boarchuz" you correctly pointed out my first mistake in the schematic. For this board I have jumped CE with VIN. In next board I will correct this mistake.

Schematic_Zeni2412B.jpg (89.7 KiB) Viewed 2465 times