Python and microcontrollers

There have been various attempts to port Python on microcontrollers. The power of interpreted language cannot be kept in darkness.

Projects like Pymite, WiPy, micropython have demonstrated the concept on real microcontrollers. Among the mentioned projects micropython offers port for most affordable hardware, esp8266.

The esp8266 family can be programmed in lua, AT, C as well. In fact, Python implementation is under rapid development.

Specifications of esp8266 (version 12)

  1. High performance wireless 32 bit wireless SoC
  2. 2.4GHz 802.11 b/g/n, Wi-Fi Direct(P2P), soft-AP, RTC
  3. SDIO 2.0(Secure Digital IO), SPI, UART
  4. 16 GPIO
  5. ~50kB of RAM (not mentioned clearly in datasheet)
  6. ~1MB of Flash memory (ROM)

Application of esp8266

  1. Smart power plugs
  2. IP Cameras
  3. Sensor networks
  4. Wearable electronics
  5. Home automation

Installation

The development environment available for GNU/Linux only. One needs following repositories setup (read the instructions provided in respecive project & install all packages)

https://github.com/pfalcon/esp-open-sdk

https://github.com/micropython/micropython.git

Hardware Setup

  1. esp8266 development board
  2. USB-to-serial cable

And make sure GPIO-0 & GPIO-15 are set according to given table.

GPIO 15 GPIO 0 GPIO 2 Mode Description
0 0 1 UART Download code from UART
0 1 1 Flash Boot from SPI Flash
1 x x SDIO Boot from sdcard (not tested)

Loading micropython to esp8266’s ROM

Connect esp8266’s Rx line with Tx of USB-to-serial cable and vice-versa. Edit your micropython/esp8266/Makefile and add your USB-to-serial path, in my case it was /dev/ttyUSB0.

To install micropython you need to be in UART mode. Execute

make deploy

to compile micropython and install/upload it to esp8266’s ROM. This process might take up to 2 minutes.

Once done, you need to switch to Flash mode (see table above). Open minicom with baud rate 115200 8N1 bps and No hardware/software flow control.

Hit enter to find Python prompt >>>. That’s all, have fun !!!

Running a Python script

To run a Python script simply write the program in micropython/esp8266/scripts/main.py, this will get compiled at the build time.