The ESP-8266 boot loader prints messages at 74880 baud. That is a
non-standard baud rate which is not available as a
stty setting on
Ubuntu, so the messages just look like garbage. But, it doesn’t have to
be that way; there is a method to set arbitrary baud rates, at least for
some serial adapters.
I found out how to set a custom baud on Linux from stackoverflow. The gist worked for the FTDI breakout board from Sparkfun, but not for another no-name USB adapter I have in my toolbox. My best guess is that any FTDI based adapter will work.
The program to set a custom baud rate was compiled from source:
$ git clone https://gist.github.com/3f1a984533556cf890d9.git anybaud $ cd anybaud $ gcc gistfile.c -o anybaud
While the resulting
anybaud command can be executed from the directory where
it was built, it is more convenient to put it where it is easy to
$ sudo cp anybaud /usr/local/bin
Now, to see the messages from the ESP-8266 bootloader open a terminal
emulator (I use
minicom) and then run
anybaud to set the serial
speed to 74880. It is important to run
anybaud after the terminal
emulator has finished setting it’s default spead. I use two command line
windows. In the first I start
minicom and make any changes necessary
to open the serial port. When that is complete I run the following in
the second terminal:
$ anybaud /dev/ttyUSB0 74880
Then reset the ESP-8266. Hopefully you won’t be greeted by an error like I was!
ets Jan 8 2013,rst cause:2, boot mode:(3,0) load 0x40100000, len 27452, room 16 tail 12 chksum 0xaf ho 0 tail 12 room 4 load 0x3ffe8000, len 920, room 12 tail 12 chksum 0x30 ho 0 tail 12 room 4 load 0x3ffe83a0, len 3072, room 12 tail 4 chksum 0x7b csum 0x7b system param error ff ff ff ff ff ff ...
Clearly I have some work to do, but at least I know about it now!
Subscribe to this blog via RSS.