ESP8266 Community Forum

- Mon Dec 21, 2020 2:33 am #89879 I have an ESP-12, which I don't know much about it's origin other than it was probably purchased as a secondary item from an Aliexpress or Ebay vendor, along with an ESP-01, and that was a number of years ago and I essentially forgot that I had bought them.

I recently found my two modules, and after many trial and errors, I was able to determine the ESP-01 is an older 4Mbit module, successfully replaced the third party firmware (ai-thinker) with the latest AT version from Espressif supporting 4Mbit ESP-01 modules and have been using it in a simple circuit sending temperature data via UDP to my server.

Using what I learned with the ESP-01, I am now trying to update the firmware on the ESP-12, but I can't seem to find any way to flash the module, either using command line tools, the Arduino IDE, or the Espressif download tool (V3.8.5).

Nothing I do seems to work in recognizing that there is an ESP-12 module connected (all the tools just time out), and the only way I can see any life is to boot with a FTDI adapter connected at 74880 baud, and this is what I see:

ets Jan 8 2013,rst cause:2, boot mode:(7,0)

waiting for host

or, while holding GPIO0 to GND while resetting:

ets Jan 8 2013,rst cause:2, boot mode:(5,0)

waiting for host

The module itself is soldered to a white carrier board and my breadboard circuit is setup like this instructable.

RST - 10k to Vcc switch to GND
CH_PD - 10k to Vcc (on the carrier board)
GPIO15 - 10k to GND (on the carrier board)
GPIO2 - 10k to Vcc
GPIO0 - 10k to Vcc switch to GND

I am using a genuine FTDI usb adapter (Sparkfun) and the ESP-12 has a clean 3.3V from a bench supply.

At this point, all I am attempting to do is flash with the latest AT firmware from Espressif.

What are my next steps in determining what is needed in troubleshooting and getting this module working?

Thanks in advance,

Justin

- Sun Dec 27, 2020 12:29 am #89970 Seeing the boot message it *looks* like it's working fine.

If you want to program it (using any flasher you wish), you'll have to put the ESP in programming mode (like you did with the ESP-01):

• Keep and hold GPIO0 low (using a switch is easiest)
• Press and release RESET
• Make GPIO0 high again
• "Press play on tape" (start the flasher program)

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.

- Mon Dec 28, 2020 3:53 pm #89988 That's exactly my problem, following the normal procedure to flash the module, nothing works. The flash tool times out waiting for a response from the ESP-12. It's like the module doesn't recognize or doesn't receive what's coming in on it's RX pin.

I have captured the RX and TX pins on my logic analyzer and can see the boot message from the ESP-12 and the "flash" message from the flash tool, but no response from the ESP-12. I have verified that the RX pin on the carrier is actually connect to RX on the ESP-12.

Everything seems that it should be working.

My next step is to remove it from the carrier board, solder on some leads, and see if it makes any difference.

Thanks,

Justin

- Tue Dec 29, 2020 9:20 am #89999 What speed are you trying to upload at?

Device starts up with serial at 74880 for the initial boot message but then switches to 115200 once the clock generator is initialised to deal with the standard 26MHz crystal.

You should try uploading at 115200 if you are not already doing so.