First steps with Micropython on a NodeMCU

My NodeMCU arrived so I went right ahead and installed Micropython on it.

Install the Micropython firmware

To copy the firmware onto the board, you can use esptool. It can be installed with pip, so I created a virtualenv for installing it. Esptool requires Python 2.

$ mkvirtualenv -p $(which python2.7) esptool

Install esptool in the virtualenv:

pip install esptool

Plugging in the nodemcu gives me /dev/ttyUSB0.

Erase any existing firmware:

$ esptool.py --port /dev/ttyUSB0 erase_flash

Downloaded the pre-built micropython firmware, then write the firmware to the device:

$ esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=8m -fm dio 0 esp8266-20160809-v1.8.3.bin

Now replug the device (or hit the RST button).

Enter the REPL

I used picocom.

$ picocom -b115200 -ep /dev/ttyUSB0

picocom v2.1

port is        : /dev/ttyUSB0
flowcontrol    : none
baudrate is    : 115200
parity is      : none
databits are   : 8
stopbits are   : 1
escape is      : C-p
local echo is  : no
noinit is      : no
noreset is     : no
nolock is      : no
send_cmd is    : sz -vv
receive_cmd is : rz -vv -E
imap is        :
omap is        :
emap is        : crcrlf,delbs,

Type [C-p] [C-h] to see available commands

Terminal ready

Press enter to see the prompt:

>>>

Notes

• Specify the baudrate of 115200. Without this it said Terminal Ready, but there was no prompt and I couldn’t communicate at all. Once I specified the baudrate with the -b option, the prompt appears (after pressing enter).

• I changed picocom’s escape command to C-p with the -e option, because C-a clashed with my tmux setup.

• To exit use [C-p], C-\, [C-p], C-x.

Now see

How to copy files to a Micropython device