ESP8266 Community Forum

- Wed Feb 24, 2016 5:49 pm #41831 Thank you on your constant help. Changing to the nodemcu fixes the problem of repeated upload, now this error does not appear anymore.

But the original problem persists. Still no program is left in flash after power is disconnected.

- Thu Feb 25, 2016 4:08 am #41848

Thank you on your constant help. Changing to the nodemcu fixes the problem of repeated upload, now this error does not appear anymore.

But the original problem persists. Still no program is left in flash after power is disconnected.

If it can help, I have just the same problem.

I have sketch that measure temperature, humidity and a sensor and upload the data to a MQTT server. If works well during days, but when I disconnect (just after uploading the sketch of after many hours) it lost its configuration.

I tested with two different NodeMCU of different manufactures with the same outcome.

- Thu Feb 25, 2016 9:32 am #41863

Still no program is left in flash after power is disconnected.

I don't think the Flash is emptied at all. I'm still convince that it is a Boot mode issue where GPIO2/GPIO0 are not HIGH when power is recycled, for some unknown reason.

- Thu Feb 25, 2016 10:23 am #41866

Still no program is left in flash after power is disconnected.

I don't think the Flash is emptied at all. I'm still convince that it is a Boot mode issue where GPIO2/GPIO0 are not HIGH when power is recycled, for some unknown reason.

And you were right! GPIO0 had a short circuit to the ground due to manufacture error of PCBs on which ESP was soldered on. Because of that, on every power-on it went to the bootloader mode..

@Ferndando, you might also for this mistake. Use the multimeter and measure resistance between GPIO0 / GPIO2 and gnd / 3.3V. If any mistakes as mine, you will see them.