ESP8266 Community Forum

- Sat Feb 02, 2019 5:51 am #80382 The ESP-12 has an internal pull up on the RST line. Using a pull down resistor on GPIO15 is a good idea as it protects the pin from getting short circuited if the sketch (or a crash) managed to set it to output. It won't materially affect setting the boot mode to download. A 10K pull down is marginal as there is a weak internal pull up so you don't get a good solid low. I would use a 4.7K.

Have you selected an ESP-12 board type in the IDE (e.g. espino)?

- Sat Feb 02, 2019 3:33 pm #80386 Here are the two separate instructions I got from you:

For the ESP-12 then GPIO0 needs to be at 0V when the board is reset. So move your GPIO0 wire to 0V, then do a reset by connecting RST to 0V temporarily. Move the GPIO0 wire back to high and your are ready to upload the sketch.

You should have a 10K pull-up resistor to VCC on the REST (reset) line and a 10K pull-down resistor to GND on GPIO15 rather than the direct connection to GND.

I will try again to send you a file of the schematic I creates, based on the combination of the two instruction sets. I held down the gpio0 button while temporarily pressed the GPIO15 & the reset button. Then I tried an upload, with the same error message.

Attachments

Schematic

- Sat Feb 02, 2019 4:30 pm #80387 I had a small error connecting the power supply to the ESP-12. I fixed it, but it still failed, but I got a different error message, when I fixed the error. I just realzed I am setting the board to NodMDU1.0(ESP-12E) in the IDE. Should I be using a different setting? Here is the different error message:

esptool v0.4.13 - (c) 2014 Ch. Klippel <ck@atelier-klippel.de>
setting board to nodemcu
setting baudrate from 115200 to 115200
setting port from COM1 to COM11
setting address from 0x00000000 to 0x00000000
espcomm_upload_file
espcomm_upload_mem
setting serial port timeouts to 1000 ms
opening bootloader
resetting board
trying to connect
flush start
setting serial port timeouts to 1 ms
setting serial port timeouts to 1000 ms
flush complete
espcomm_send_command: sending command header
espcomm_send_command: sending command payload
read 0, requested 1
warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
error: espcomm_upload_mem faile

- Sun Feb 03, 2019 8:03 am #80394 ESP8266 Boot Modes

MODE
UART Upload GPIO0= 0, GPIO2=1, GPIO15= 0
Normal Run GPIO0= 1, GPIO2=1, GPIO15= 0
SD Card Boot GPIO0= 0, GPIO2=0, GPIO15= 1

Your latest schematic has a button on GPIO15. You don't want that. GPIO15 must be a logic low at reset time for both normal running and for putting into upload mode. Pull it permanently down to ground through a resistor, 4k7 for preference although 10K will probably work. You have GPIO2 connected direct to 3.3V. GPIO2 needs to be high at reset time, but it is not a great idea to connect it direct due to danger of damaging the pin if the sketch ever sets it to output mode logic low. Eithe ruse a 10K resistor to pull it up or leave it floating as it has an internal pull up.

It is GPIO0 that makes the difference in selecting between normal running and getting into upload mode.

So you push the GPIO0 button to connect to )V, then press and release the reset button. Then release the GPIO0 button. THe module should now be in upload mode and you can send the sketch.

I select the espino board in Arduino for esp-12 modules although the NodeMCU version will probably work.