Can't Manually Enter Bootloader Mode

[pdihawk]

I have a ESP32-DEKITC-32E board that I'm trying to program with Arduino.

I can successfully program the board if I use a USB to Serial adapter when I hook up RTS to the enable and DTS to GPIO0.

However I would like to be able to program it without RTS and DTS. I would do this by the method I have seen everywhere:
-Start programming
-hold Enable LOW, hold GPIO0 LOW
-allow Enable to go HIGH
-within 100-200ms, let GPIO0 go HIGH

GPIO2 is strapped LOW too.

When I try this with Arduino, it times out waiting for packet header.

I don't see any reason why this isn't working. Does anyone have an idea why this isn't working for me?

[pdihawk]

Ok, I just realized my problem.

I have two of these dev boards and realized on the first that I needed to remove the R17 and R18 in order to get it to download. These are the 0Ω resistors that connect the onboard USB to Serial TXD and RXD to the ESP RXD0 and TXD0.

At some point I switched to the second dev board and forgot to remove the resistors.

I am now able to download!