ESP8266 Community Forum

- Thu Jan 08, 2015 1:04 pm #6705 Got the blue power led one but having the exact problem..

Can't flash and there is no at firmware on chip.. No serial output.. just blue led..

Tried

gpio 0 + gpio 15 + GND -> GND
CH_PD + VCC -> 3.3v
TX-> RX
RX -> TX

just blue led... nothing more, nothing less..

- Thu Jan 08, 2015 10:05 pm #6761 Hi,
I thought I'd share my previous troubleshooting experience in case it might benefit someone.
Initially, I had some issues getting my ESP8266 working but here's the steps I took.

Connected the pins properly (includes connecting GPIO15 to GND and CH_PD to VCC. I left GPIO0 unconnected.
Tested with 9800 baud serial with CR LF sent. (I read somewhere that after upgrading the firmware, the baud should change to 115200)
After all that, it still failed to respond over the FTDI cables I had, so I tried connecting it through an Arduino and modified SoftwareSerial example sketch to act as a serial proxy.

That did the trick and I managed to get it working finally.

- Fri Jan 09, 2015 3:50 am #6773 I have also had some trouble programming my ESP-07 (16 pin variant).

It has blue power led and red activity led like yours.

I came back to it to see if I could get new firmware, and (partly thanks to you setting out the connections etc in your post, made it really easy to duplicate) I was able to get lua firmware onto the module and then reboot into normal mode.

If you can flash firmware then a lot must be right with your setup - vcc, gnd, tx, rx, ch_pd and GPIO15 must all be right for this to work, in my experience.

You can double check this by attempting to flash firmware but deliberately leave GPIO2 floating, for example, just to confirm that your esptool flashing procedure is good.

So the problem must be in getting the module back after flashing. I assume you've tried several different firmware files to rule out corruption? If it helps my nodemcu_20150107.bin has a md5 of f4a5eca130c5e549093d5bf2d21a9c36.

Have you tried explicitly pulling the GPIO2 high? perhaps it's floating low in your situation? Have you tried operating the reset by pulling it low briefly?

If you don't get anything, even garbage, at any point, then try turning it off and on again!

Have you got any other modules that you have success with?

Good luck

- Fri Jan 09, 2015 4:44 am #6779

I have also had some trouble programming my ESP-07 (16 pin variant).

It has blue power led and red activity led like yours.

I came back to it to see if I could get new firmware, and (partly thanks to you setting out the connections etc in your post, made it really easy to duplicate) I was able to get lua firmware onto the module and then reboot into normal mode.

If you can flash firmware then a lot must be right with your setup - vcc, gnd, tx, rx, ch_pd and GPIO15 must all be right for this to work, in my experience.

You can double check this by attempting to flash firmware but deliberately leave GPIO2 floating, for example, just to confirm that your esptool flashing procedure is good.

So the problem must be in getting the module back after flashing. I assume you've tried several different firmware files to rule out corruption? If it helps my nodemcu_20150107.bin has a md5 of f4a5eca130c5e549093d5bf2d21a9c36.

Have you tried explicitly pulling the GPIO2 high? perhaps it's floating low in your situation? Have you tried operating the reset by pulling it low briefly?

If you don't get anything, even garbage, at any point, then try turning it off and on again!

Have you got any other modules that you have success with?

Good luck

As far as i can see, ecotpl0721 successfully flashed the module before, me on the other hand, just gazing the blue led. Led is blue, board is blue even the antenna is blue!.. I had no problem with ESP03 and ESP01 but this one is killing me..

Tried all, not even a single char sent by the module with all combinations.. Tied the GPIO2 to an another serial to see some uart debug, but all i got was a nul for every power-off-on at 74880 :/ There has to be a proper way. I have 5 modules, 3 of them are like this.. gonna try the other 2 this afternoon.. :/