15 Dec

Firmware Update on an ESP8266

The ESP8266 is an incredibly cheap (as in $3) wifi module for use in embedded projects. A few weeks back I ordered several of these little jems, and have been having lots of fun connecting all sorts of stuff to my LAN. A  couple of weeks ago the manufacturer released an updated firmware build that really increases the stability of the ESP8266, so I spent some time over the weekend upgrading them. It’s not difficult, but there are a few tricks to it.

First, make sure you’re using a 3.3v serial interface. 5v will kill the module. I’m using a 3.3v generic Silicon Labs from Pololu. You can order them here.

Connect the module’s GPIO0 to ground. This puts it into firmware update mode.

Download esptool.py from here. If you don’t already have it installed, you’ll need to install pyserial as well.

<note to=”self”>your copy is in ~/src/pyserial-master</note>

Download the firmware – I’m currently using the version that can be found here.

Unzip the firmware into the same directory as the esptool.py script.

If you’re using a Mac, you might have some issues with the —port option. I wound up hard-coding the /dev/ttyXXX entry for my USB programmer into the script.

<note to=”self”>your programmer is on /dev/tty.SLAB_USBtoUART</note>

Upload the firmware as follows:

./esptool.py write_flash 0x00000 boot_v1.1.bin
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