ESP8266 Community Forum

Hi!

I've got a pair of NodeMCU 0.9 devkits, and I'm hitting all kinds of walls flashing them.

I'm on OS X and using the mac-usb-serial.com drivers.

Long story short, no matter what I do, I end up in boot mode (1,6) (UART) or (3,6) (SPI) - and in (1,6) the device doesn't appear to respond to flashing.

Using an external UART gets me in to (1,7) every time.

Anyone know what the second number means and how to fix this?

Make sure the all 3 pins are pulled up or down as required. Leaving them floating is not a guarantee that it will read as High.

GPIO15 is often not mentioned and forgotten about, because everyone is talking about the first ESP-01 modules which have GPIO15 pulled high internally on the PCB.

Yeah, that table describes the value of the first part of the boot code; it's the second part (6 or 7) that's confusing me.

Attaching an external UART shouldn't do anything different, right?