ESP8266 Community Forum

- Sun Dec 27, 2015 1:08 pm #37251

Hi,
I'm new to the ESP8266 world and struggling to get a couple of ESP-12 boards to work. I got five of these from an indiegogo campaign and don't exactly know what firmware is installed (maybe none?).
Reading a ton of different sites with mostly the same but sometimes conflicting information I ended up with the hardware setup described below.

Connecting with a terminal program at 77400 baud I'm able to see the boot message like "ets Jan 8 2013,rst cause:1, boot mode:(1,7)" with the values changing depending on power-up vs reset and depending on the state of GPIO0. I guess that means at least the ESP->PC direction of the communication is working fine. No matter what baud rate I chose (9600 / 57600 / 115200) I don't get any additional information on boot/reset.
I can't flash another firmware either:
- Connecting GPIO0 to GND and the powering up the module, then starting the nodemcu firmware programmer tool (latest version) it shows the two MAC addresses and then starts loading but at ~5% it stopps
- Connecting GPIO0 to GND and the powering up the module, then starting the flash program it starts with "deleting flash" but then after a few seconds shows the "invalid packet header" error message

Hardware:
CH340 based USB serial adapter switched to 3.3V - GND connected to power supply GND
separate power supply (1A USB phone charger at 5V connected through low drop voltage regulator with proper caps)
ESP-12:
- VCC/GND - connected to voltage regulator output with additional 100uF close to the module
- CH_PW - connected via 12k R to VCC
- REST - connected via 12k R to VCC and push-button to GND for reset
- TXD - connected to RXD of CH340
- RXD - connected to TXD of CH340
- GPIO0 - connected via 12k R to VCC and Jumper to GND for flash mode
- GPIO2 - connected via 12k R to VCC
- GPIO15 - connected via 12k R to GND
- all other pins floating

Did you ever get this sorted? I'm having same issue with Banggood ESP-12 modules.

- Sun Dec 27, 2015 1:23 pm #37252 FT232RL usb converters in my case were not reliable ,, They could not load FW
only 2 of 10 would load FW and 1 of those had intermittant loads..

I use a CRYSTAL controlled usb converter[ D-SUN aliexpress , Prolific clone I think]
I now have very few FW load issues.

As for using the 76800 Baud--hmm--tried using several times, I could get output msgs ok
I was only able to send info 1 time

I use what seems the standard 9600 or 115200

- Mon Dec 28, 2015 7:26 am #37305 Hello,


I am using ESP-12 modules. The big difference between ESP-12 and ESP-01 modules is the hardware reset management. When you power on the device, there is a transitionnal delay before all of the CPU power supplies reaches and stay to there nominal values.

When powering-up the module, you need a power-on-reset circuit. This is achieved by connecting a 10nF capacitor between the rst pin and GND. This capacitor is very important :

- It maintains the rst pin to low during a few mS, allowing the CPU to boot in sane conditions,

and

- It debounces the push reset button, allowing a safe reset procedure.

Without this cap, the CPU runs randomly.

EDIT : this capacitor is labelled C2 on the Nodecmu schematics. 10nF is a good and easy to find value.

- Tue Dec 13, 2016 5:49 pm #59476 I can not make my ESP 12 to communicate all. I hade no problems with ESP module 01. Worked fine.
It is not sending any message to the serial. I' using arduino IDE.

I eventualy landed on a "Kolban’s book on the ESP8266", did every thing that i could find in that book.
Operating system recognises that " something" is in the usb port, but can not comunicate with it (linux (ubuntu) and win 10).

When i try to flash it with arduino ide it gives standard message

warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed

As i said I din't have any problem with esp module 01.
I have tried to change almost all of the available options in the " tools" menu in arduino ide. Nothing on a serial monitor , thried this with arduino serial, putty and minicon ( although I am not sure if i am using minicon correctly)... thried every baud rate that there is.

I have check my schematics multiple times.

I'm using some kind of CH340 based usb-uart adapter. Worked fine with esp8266-01
http://www.ebay.com/itm/1PCS-ESP01-Programmer-Adapter-UART-GPIO0-ESP-01-Adaptateur-ESP8266-USB-NEW-/222121082897?hash=item33b772c011:g:BVMAAOSwB9xXOuiG

I have tried to use node mcu flasher, just to see a results, not getting any MAC adreses. Regardles of that i have presed "flash " and got theese messages in log

Note:Serial port connected.
Note:Begin find ESP8266.

After that nothing happens, i have thried to enter its default -bin files that i got with downloading it from github....nothing

I was wondering, as far i can see this esp has 2 LE diodes. One of them only turns on when i push the reset buton (don't have capacitor on it ....i hold it for at least 3 seconds) and when i turn on/off ch_pd pin (EN on my bord). Bouth of them only light up when I conest GPI0,2, and 15 to GND. What is that , what is " Remapping" as i have found.

I thing that the process for flashing esp 01 and 12 boards should be the same... am i right ? (exept gpio15 to gnd)

I think that the best thing will be to change usb to uart adapter...but that takes too long (shiping from china)
i dont't have external power suplly on this...power it from usb port, but i don't see how this could be an ishue because i an not using wifi . I will be most happy to see bootloging message