ESP32 Forum

I need some advice.
I have designed a PCB using a ESP-WROOM-32 & SDMMC & CH340G.
The problem is that the CH340G uses the two transistors for set the programming mode.
If I have an SD card inserted into it's socket, the WROOM will not go into programming mode.
I release the SD card, and its fine.

Is there a correct schematic where the SD card does not interfere with the Boot process.
I know its the IO2 pin.
What is the proper circuit ?

The schematic attached is my pcb schematic.

Please have a look at the wrover-kit schematic (https://docs.espressif.com/projects/esp ... s.html#id8). It has the additional transistor on GPIO2 to pull it low when entering download mode.

I added the extra isolation transistor, but I have the same proble.
I can not go into programming mode with the SD card inserted.

Please see attached schematic.

Did you check oscilloscope? Maybe EN pin goes high before IO2 goes low because of no cap on EN + strong pull-up, and capacitive effects of SD card on IO2?