So you're a Noob? Post your questions here until you graduate! Don't be shy.

User avatar
By db533
#71296
philbowles wrote:
Unfortunately, me too. First to admit my code/electronics skills ratio is 85/15 . There do seem to be a lot of folk out there who have a similar issue, even to the point of stating the 26MHz is "normal" or "default output mode" for that pin, but I don't really understand what that means.

To me, if it were "normal" you upload would start flashing...got to be another (probably a slap-the-head doh!) answer somewhere. I'll be fascinated when you find it. Do let us all know.


Phil, thanks for your suggestions! Much appreciated!

I have been working on this for last few hours. I ripped out the ESP-12 from my circuit and all the 1.5 in / 5cm connecting cables and replaced them with a ESP-12 prototyping board http://hobbycomponents.com/esp8266/838-prototyping-adapter-for-esp-07-esp-08-esp-12 that thankfully fit on my existing stripboard. Soldered on a previously used ESP-12F (unfortunately building up a collection of unsuccessfully used ESP-12F...). *** This did get rid of the clock signal on GPIO0. ***

So, I had shortened the connections from stripboard to ESP by using the prototype board and I had changed the ESP-12F module and with that, got rid of the clock signal. :D

But, despite all the correct voltages and no clock, the ESP-12F was not receiving program when uploading. So I suspected that I had used a bricked / fried ESP-12F. So I tried unsoldering the ESP-12 from the prototyping board, but ruined the tracks on the prototyping board.... :shock: So then I removed the prototyping board and replaced it with a 2nd prototyping board and a new ESP-12F.

Power on, follow the procedure for getting into program mode, and... clock signal is back. :!:

I have spent a few months trying to get these modules to work reliably and I'm now searching for alternative modules because they just seem too delicate to use in practice. But I will keep this thread open and will keep my circuit and will gladly test any suggestions to fix this issue.
User avatar
By Viper-7
#91774 Very old thread, but still high on search results. For people experiencing this issue, the most common cause is the serial programmer interface. If you connect your serial interface before powering up the chip itself, the TX line will supply a tiny bit of current to the ESP, which will prevent normal startup when you DO provide power.

Disconnect your programmer, power up the circuit, then attach your programmer, and the clock out on GPIO0 thing should stop happening :)