ESP8266 Community Forum

- Tue May 05, 2015 11:36 am #16589

I had the same problem with ESP-12. Based on some other info in this forum, found that baud rate was running at 74880. Using putty checked with this baudrate and the board was still alive.
All of these hints with IO15 and a lot of other hints did not help.
At the end, I tried an old version of AT-based firmware. This worked fine, after a lot of stopped flashings.
Next tried to upload nodemcu v0.95 which worked on first try, and next flashed 0.96 which also worked fine.
Not sure what helped at the end, all together I spent about 2 days.
BTW, never had similiar problems with ESP-01.
Regards from Krefeld
Jürgen

Success! I flashed it with NodeMCU 0.9.5 (integer) and now it works. Will try to flash it with the latest version now.

Thank you!

Robot enthusiast | Indie developer | Enjoys life

- Tue May 05, 2015 11:55 am #16596

At the end, I tried an old version of AT-based firmware. This worked fine, after a lot of stopped flashings.
Next tried to upload nodemcu v0.95 which worked on first try, and next flashed 0.96 which also worked fine.

I have several times rescued non-responding ESPs by flashing AT firmware, then NodeMCU again. I have no idea why this works, but for me it does.

- Wed May 06, 2015 1:14 am #16666 I'm new to the ESP8266. Have an ESP-12, but sadly the device seems bent on having exception errors. Fresh from China, I couldn't comm with it (and I'm using 3.3V FTDI). Eventually found LuaLoader, and the 74880 speed setting which enabled me to see the exception error messages, for all the good that did me.

Have tried multiple iterations of flashing it (with ESP8266Flasher) - AT, NodeMCU, Integer, 0.9.3, 0.9.4, 0.9.5. A big problem I'm running into is little detail about what addresses different images should be loaded at, and a fairly consistent "uncheck these images and just update this one" -- I've no idea if the expectation is that the new image is everything and doesn't need the other data images, or if the old images are expected to already be on the device at their respective addresses.

The exception address is consistent within an image loaded a certain way - if I load a different image, or to a different address, the exception tends to change, so I know the flashing is happening. the flash tool log shows no errors. in the LUALoader console (thus far being used as a console only), I get messages about load from certain addresses, a certain length, and "room", plus tail and checksums from the loader before the exception. No idea what is supposed to be expected for any of these values.

I have yet to issue an AT command to this device because of the exceptions.

Perhaps the AT image and whatever else is necessary to back-rev the device could be documented here? Where is this 0.9.6? The 'latest' image from the nodemcu repo on github is 0.9.5. From February.

I'm not currently set up with the toolchain for this - was rather hoping to just use pre-built components and jam my own scripting on there for once, and I'm figuring if the pre-built firmwares are not working, it's a waste of my time to expect to build something blindly expecting it might work instead.

Thanks for any assist here.

- Thu May 07, 2015 11:50 am #16820 A bit more tinkering, still no joy.

I can flash different boot loaders, 1.1 or 1.2, and this is reflected in the boot message on the device, so I know it's in flash mode and flash is capable of being written to.

2nd boot version : 1.2
SPI Speed : 40MHz
SPI Mode : QIO
SPI Flash Size : 32Mbit
jump to run user1

Fatal exception (0):
epc1=0x402015a4, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000


I carefully removed the shield to that I could verify parts underneath. It does indeed have a 4Mbyte (32mbit) flash device, so now I'm setting that in the size in the flashing tool, though it has made no difference (nor did I expect it to).

I'd really like to light this thing up, but nothing gets past the user load.

I have a 1K pullup on reset, 10K on CH_PD. 10K pulldown on GPIO15, Vcc on GPIO2 (though booting is indifferent if I leave it floating). Have a switch to ground GPIO0 for flashing. Supply is regulated 3.3V, measures slightly higher than that at the Vcc and GND of the module when powered up, so no indication that it's under too much of a load and dropping off (plus, I doubt the radio module is using much power if not initialized).