This appears to be the closest topic to what I’m having difficulties with, even if it is 481 days old. I have been making slow but sure progress on a project, only to hit a brick wall yesterday when my Core started doing almost exactly what is described in the opening post. Basically, the Core hangs at blinking cyan (before starting the application), but does a random fast/slow flash sequence forever. I thought it was the large code addition that I’d made to my project (bringing the BIN size to about 87KB), but I pretty much stripped the program down to nothing trying to unsuccessfully isolate the problem. (Yes, I did make a code backup first!) Obviously, when it won’t initialize, the only options are DFU-UTIL or a factory reset (for OTA programming).
At first, I could factory reset and FLASH Blink_LED onto the Core (via OTA or DFU-UTIL)
and have it initialize to breathing cyan (and blinking D7)–but now that doesn’t work anymore.
I can still factory reset to Tinker, which initializes to breathing cyan. It’s fully initialized, as I can control it from my phone–or pretty much soft-brick the Core by flashing Blink-LED or my practically empty program to it. --WAIT–now that isn’t working anymore! An OTA flash goes to flashing purple on the Core–but it gets stuck with “purple” for a few seconds, “off” for five seconds, maybe five purple flashes, then back to stuck. Then it just gives up, resets, and blissfully initializes to Tinker (breathing cyan).
I can DFU-UTIL the Blink_LED BIN file onto the Core…but after the green-flash “Connecting to Wifi”, I just get the “broken lawnmower” rapid random alternating between fast/slow flashing cyan, and it won’t start. What on planet earth have I done? (I know I haven’t done anything on Mars ).
- I’ve successfully done DFU-UTIL flashing before, so don’t think that’s the problem. Perhaps @kennethlimcp has some insight?
- I can communicate with the Core via Tinker (after a factory reset and WiFi setup), so it doesn’t appear to be the Cloud keys.
- I’ve seen more error codes from this problem than with any prior one! Three red flashes, or one long red flash–or 3 seconds of rapid red flashes, or any other combination of resets, etc. My Wifi is good, running ~5MBits up, ~2MBits down to the Internet.
Just for the record, I created a shortcut in “C:\Users\[username]\AppData\Roaming\Microsoft\Windows\SendTo” linked to DFU-UTIL, so I can right-click a BIN, and click, “FLASH with DFU-Util.” The shortcut’s target is [“dfu-util.exe” -d 1d50:607f -a 0 -s 0x08005000:leave -D]. Windows automatically appends the %1 on the end.