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Programming and Reflashing the ESP8266 ESP-01

Instructions tested on April 2017, may be outdated! - The following instructions require technical skills and assume that you are using my LELESP dev board (or a similar one)

I connected the module to my PC through the FTDI cable. At this point, I wanted to start talking to the ESP. For that, a terminal emulator like picocom or the standard screen command will do the job. First, your board might talk at any of several baud rates. The ones to try first are 9600 and 115200 (it depends on the version of the firmware running onboard).

Please note that most recent ESP firmwares require Carriage-Return-and-New-Line (\n\r - ASCII 10 13) line endings. Hence, you need press followed by Ctrl-J to send a command. However, picocom can be easily configured to send a linefeed after each carriage return. So you can run picocom as follows.

picocom -b 115200 /dev/ttyUSB0 --omap crcrlf

and you are ready to send your first commands!

If your serial transmission rate is correct, try typing “AT”: it should echo the characters as you type them and should return an “OK”. And you are now ready to start working with the ESP8266.

AT version:  5 2015 16:27:16)
SDK version:1.1.1
Ai-Thinker Technology Co. Ltd.
Jun 23 2015 23:23:50
 ets Jan  8 2013,rst cause:2, boot mode:(3,7)
load 0x40100000, len 1396, room 16 
tail 4
chksum 0x89
load 0x3ffe8000, len 776, room 4 
tail 4
chksum 0xe8
load 0x3ffe8308, len 540, room 4 
tail 8
chksum 0xc0
csum 0xc0
2nd boot version : 1.4(b1)
  SPI Speed      : 40MHz
  SPI Mode       : QIO
  SPI Flash Size & Map: 8Mbit(512KB+512KB)
jump to run user1 @ 1000
Ai-Thinker Technology Co. Ltd.

Note the noise when you reset the device: some typical bootup messages are sent at 76800, . But there should be a ”ready“ message at the selected baud rate if your UART Rx is wired correctly.

So, ESP8266 boots up into the serial modem mode, and you can communicate with it using a set of AT commands (historically AT commands are based on the Hayes Command Set). Have a look at a list of the AT Commands supported by ESP8266 for more information on the commands shown above.

esp8266/firmware-programming.1549144532.txt.gz · Last modified: 2019/02/02 21:55 by admin