@ajb2k3 said in Core 2 bricked after attempting to install firmware:

Connect 3v3 to the 3.3V pin or 5V to the 5V pin, do not connect both and do not have any other cables plugged in!

Just to clarify. You don't do anything specific to bring it into boot loader mode? ESP32 documentation seems to indicate one should bring GPIO 0 low (attach it to GND) to force this.

Not I did once manage to make a FT232R programmer work with it as I was messing with some combination of that and a few other things. So I think I managed to erase it. But I am not having much success replicating and getting another connection.

@ajb2k3 said in Core 2 bricked after attempting to install firmware:

Just remember that the Programmers TX must be connected G3 RXD and the programmers RX pin must be connected to G1 TXD pin along with the GND pin.

Connect 3v3 to the 3.3V pin or 5V to the 5V pin, do not connect both and do not have any other cables plugged in!

Hmm. No go with two different FT232R adaptors. Maybe I did manage to damage it somehow. It still boots and runs the factory test though. So the chip and board does seem to be functional.

.. Or maybe something else it wrong. Trying to flash through the pins does not seem to work on my Core2 that works on USB.

@ajb2k3 said in Core 2 bricked after attempting to install firmware:

Have you tried updating the CH9102 usb drivers?

No. For me I have two identical devices. One works without issue. The other does not. On both macOS and Windows 11.

@ajb2k3 said in Core 2 bricked after attempting to install firmware:

yes, GPIO 1 and 3 are the pins you need to directly connect to.

Ah okay. My confusion is from here. That could indicate 1 and 18. But I realise now the wire that hits G18 is not what is labeled U0RX.

None of the tricks with holding buttons does anything for the device I have that does not present a serial port over USB. While I'm mainly on macOS I can't make it do anything in Windows either. There I will just have an "Unknown USB Device (Device Descriptor Request Failed" entry in Device Manager.

So I'm more interested in how to connect directly to the internal TX/RX pins. But I am not entirely sure how to access them on this board.

Looking at the schematics more closely It seems the on-board connector is also for USB. But I am having a little trouble figuring out if any of the "M-BUS" pins connect. Maybe G1 and G18? G1 makes sense from the markings (TXD0). But G18 is marked as SCK (So a clock signal?) and G3 (marked RXD0) would make more sense.

@ajb2k3 said in Core 2 bricked after attempting to install firmware:

Failing that you will need to remove the base and connect a USB to UART adapter to the internal TX/RX pins and override the core2's onboard adapter

Having a similar issue with one of my two Core2 v1.1's I am wondering how this works exactly? I assume we are talking about the 4pin connector with (DP, DM, GND, 5V)? In which case DP/DM is TX/RX - although I am not sure which would be which.

@ajb2k3 said in Core 2 bricked after attempting to install firmware:

Try removing the base, hold the reset button (next to the card slot), plug the USB cable in.

Does not seem to do anything. Although I do seem to on rare orations be able to get it into some state where the computer recognises it as a serial port. But it also seems not to actually work when I try to write to it.

@ajb2k3 said in Core 2 bricked after attempting to install firmware:

One thing I did find is that the driver on the host computer is very unstable and prone to hard crashing. When you get a hard driver crash you need to do a hard shutdown of the computer. which means the host computer MUST be fully powered of for 30 seconds ignorer for the host computers ram to be wiped of data!

Having two devices sort of rules that out. The other device works without issue for now.