ESP8266 Community Forum

- Tue Nov 10, 2015 2:00 am #33597 HI all, I know this subject has been beat to death, and I'll apologize for starting another thread, but I can't seem to find what would answer my question.
I've successfully flashed an ESP07 with nodemcu using the flasher associated. Now I try to flash an ESP12 and have issues. I know the module tested good when I received it , testing with AT commands. I also have read about additional GPIO conditioning on the ESP12 . What is happening is that the flasher receives the mac address, flashing starts runs for about 10 seconds or so and stops. Checking the log shows around 20+ successful writes, then a time out error. I've seen this issue discussed all over the internet, with no real answer offered. I won't bore you with minutia, power is good, wiring verified, ports are working, again flashing starts then...........timeout. Any help appreciated.

- Tue Nov 10, 2015 9:50 am #33622 What kind of USB->UART connector are you using? There have been threads that say that they are not all good ...

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- Tue Nov 10, 2015 11:20 am #33625

What kind of USB->UART connector are you using? There have been threads that say that they are not all good ...

Hi Kolban, I'm using an FTDI, the same one I used to flash the ESP-7. I continuously use the FTDI with ESPlorer to load sketches to the ESP-7. I should also mention that the ESP-12 appears to be a 12-e by its physical appearance and is mounted on one of the "breakout boards" that have recently come available, as with the ESP-7.


UPDATE: Boy is my face RED I should have checked and tested bypassing my breadboard....yeah I hardwired the FTDI to the ESP 12 and only used the power/ground rails on the breadboard, and it flashed without a hitch......word to the wise.

- Tue Nov 10, 2015 1:34 pm #33633 Some interesting side notes to the ESP-12. On this particular module (this one in my hands), there is a blue led that flashes when serial data is being transferred to/from the FTDI . I'm not sure if it's receive or transmit. There is no red led to indicate power. In a quiescent state, you really can't tell if anything is happening.
I was working with a sketch on the ESP-7 to control 2 GPIO pins (2 and 4) via wifi, (RandomNerd tutorials) so for a test I just uploaded that for a function test using ESPlorer.
Now the good part. When I turned on GPIO2, (which is indexed to 4 in nodemcu) the led lights as expected. If I turn on GPIO4, (which is indexed to 2 in nodemcu) the led lights as expected. Wait the plot thickens. If I turn off GPIO4 that blue led I mentioned turns on. I remove my external led and reset. I now see I can, using wifi, control the blue led on the module. Is it attached to GPIO2? It would appear so. To say it another way, when GPIO2 is pulled low, the led lights. Now I'm wondering, considering the controversy I've read about pulling GPIO2 high, or leaving it float to flash, how it would effect things. Just for the record, I let it float. I have a photo I got from somewhere showing the pinout on the ESP12. The footnotes state tying the usual reset and CH-PD high, and GPIO-0 high for normal operation and low to flash. It states GPIO 15 should be grounded for both normal and flash mode. It doesn't mention GPIO2.