# Problem Flashing ESP8266-01

I am trying to flash an ESP8266-01. I connect GPIO0 to GND, and toggle reset to ground and back, to put the ESP01 into flash mode. The blue led on the ESP flashes once, not twice. It used to flash twice, and I could send AT commands via a serial monitor, and it worked well. I connected to my router and got online. All good.

I am using a 5v 1A wallwart to power the ESP via LM1117 3.3v.

After trying to upload a program to the ESP via Arduino IDE, things changed. Now it flashes once, and I get no response to AT commands. No echo at all.

When I put the ESP into flash mode (GPIO0 low), I just get:

ets Jan 8 2013,rst cause:2, boot mode:(1,7)


When I toggle reset (GPIO0 high), I just get:

ets Jan 8 2013,rst cause:2, boot mode:(3,7)
ets_main.c


I tried the following:

Clinic:esptool-master fedfull$sudo python esptool.py --baud 921600 --port /dev/tty.usbserial-A50285BI write_flash -fm dio 0x00000 /esptool-master/v20ATFirmwareESP.bin esptool.py v1.3-dev Connecting... Auto-detected Flash size: 8m Running Cesanta flasher stub... A fatal error occurred: Timed out waiting for packet header  I have Tried changing the baud to 9600, 19200, 57600, 74880, 38400, 115200, and 345600. The lower rates don't include the 'Auto-detected Flash size: 8m' or 'Running Cesanta flasher stub...' On further testing: Clinic:~ fed$ esptool.py --baud 115200 --port /dev/tty.usbserial-A50285BI flash_id
esptool.py v1.3-dev
Connecting...
Manufacturer: e0
Device: 4014

Clinic:~ fed$esptool.py --baud 115200 --port /dev/tty.usbserial-A50285BI chip_id esptool.py v1.3-dev Connecting... Chip ID: 0x001eb645 Clinic:~ fed$ esptool.py --baud 115200 --port /dev/tty.usbserial-A50285BI read_mac
esptool.py v1.3-dev
Connecting...
MAC: 5c:cf:7f:1e:b6:45

Clinic:~ fed\$ esptool.py --baud 115200 --port /dev/tty.usbserial-A50285BI erase_flash
esptool.py v1.3-dev
Connecting...
Running Cesanta flasher stub...
A fatal error occurred: Timed out waiting for packet header


I have rechecked my connection many times.

Does the blue led flashing once only mean anything? Any idea what I've done wrong.

• Are you sure about the baud rate? Have you tried different values? I think I remember that the default baud rate changed at some point, so depending on what model ESP8266 you've got and what version of firmware it has, it may not be 921600 baud. Nov 26, 2016 at 14:27
• Thanks for the suggestion. I tried several, and no change. At lower baud (9600), the Atu-detect Flash size does not appear.
– Fed
Nov 26, 2016 at 14:54
• Does the blue led flashing once only mean anything? It used to flash twice, and I could send AT commands via a serial monitor, and it worked well. Now it flashes once, and I get no response to AT commands. No echo at all. When I put the ESP into flash mode, I just get 'ets Jan 8 2013,rst cause:2, boot mode:(1,7)'
– Fed
Nov 26, 2016 at 14:56
• When I just toggle reset (ie non flash mode), I don't get the full startup sequence, but just 'ets Jan 8 2013,rst cause:2, boot mode:(3,7) ets_main.c'
– Fed
Nov 26, 2016 at 15:02
• Is your power suply sufficient? Nov 26, 2016 at 16:29

    ets Jan 8 2013,rst cause:2, boot mode:(1,7)

    esptool.py --baud 115200 --port /dev/tty.usbserial-A50285BI read_flash 0x0 1048576 backup.bin