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+---
+title: Getting started with MicroPython and ESP8266
+permalink: /esp8266-and-micropython-guide.html
+date: 2020-09-06T12:00:00+02:00
+layout: post
+type: post
+draft: false
+---
+
+## Introduction
+
+A while ago I bought some
+[ESP8266](https://www.espressif.com/en/products/socs/esp8266) and
+[ESP32](https://www.espressif.com/en/products/socs/esp32) dev boards to play
+around with and I finally found a project to try it out.
+
+For my project, I used [ESP32](https://www.espressif.com/en/products/socs/esp32)
+but I could easily choose
+[ESP8266](https://www.espressif.com/en/products/socs/esp8266).  This guide
+contains which tools I use and how I prepared my workspace to code for
+[ESP8266](https://www.espressif.com/en/products/socs/esp8266).
+
+![ESP8266 and ESP32 boards](/assets/posts/esp8366-micropython/boards.jpg)
+
+This guide covers:
+
+- flashing SOC
+- install proper tooling
+- deploying a simple script
+
+> Make sure that you are using **a good USB cable**. I had some problems with
+mine and once I replaced it everything started to work.
+
+## Flashing the SOC
+
+Plug your ESP8266 to USB port and check if the device was recognized with
+executing `dmesg | grep ch341-uart`.
+
+Then check if the device is available under `/dev/` by running `ls
+/dev/ttyUSB*`.
+
+> **Linux users**: if a device is not available be sure you are in `dialout`
+> group. You can check this by executing `groups $USER`. You can add a user to
+> `dialout` group with `sudo adduser $USER dialout`.
+
+After these conditions are meet go to the navigate to
+[https://micropython.org/download/esp8266/](https://micropython.org/download/esp8266/)
+and download `esp8266-20200902-v1.13.bin`.
+
+```sh
+mkdir esp8266-test
+cd esp8266-test
+
+wget https://micropython.org/resources/firmware/esp8266-20200902-v1.13.bin
+```
+
+After obtaining firmware we will need some tooling to flash the firmware to the
+board.
+
+```sh
+sudo pip3 install esptool
+```
+
+You can read more about `esptool` at
+[https://github.com/espressif/esptool/](https://github.com/espressif/esptool/).
+
+Before flashing the firmware we need to erase the flash on device. Substitute
+`USB0` with the device listed in output of `ls /dev/ttyUSB*`.
+
+```sh
+esptool.py --port /dev/ttyUSB0 erase_flash
+```
+
+If flash was successfully erased it is now time to flash the new firmware to it.
+
+```sh
+esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect 0 esp8266-20200902-v1.13.bin
+```
+
+If everything went ok you can try accessing MicroPython REPL with ` screen
+/dev/ttyUSB0 115200` or `picocom /dev/ttyUSB0 -b115200`.
+
+> Sometimes you will need to press `ENTER` in `screen` or `picocom` to access
+> REPL.
+
+When you are in REPL you can test if all is working properly following steps.
+
+```py
+> import machine
+> machine.freq()
+```
+
+This should output a number representing a frequency of the CPU (mine was
+`80000000`).
+
+When you are in `screen` or `picocom` these can help you a bit.
+
+| Key      | Command              |
+| -------- | -------------------- |
+| CTRL+d   | preforms soft reboot |
+| CTRL+a x | exits picocom        |
+| CTRL+a \ | exits screen         |
+
+
+## Install better tooling
+
+Now, to make our lives a little bit easier there are couple of additional tools
+that will make this whole experience a little more bearable.
+
+There are twq cool ways of uploading local files to SOC flash.
+
+- ampy → [https://github.com/scientifichackers/ampy](https://github.com/scientifichackers/ampy)
+- rshell → [https://github.com/dhylands/rshell](https://github.com/dhylands/rshell)
+
+### ampy
+
+```bash
+# installing ampy
+sudo pip3 install adafruit-ampy
+```
+
+Listed below are some common commands I used.
+
+```bash
+# uploads file to flash
+ampy --delay 2 --port /dev/ttyUSB0 put boot.py
+
+# lists file on flash
+ampy --delay 2 --port /dev/ttyUSB0 ls
+
+# outputs contents of file on flash
+ampy --delay 2 --port /dev/ttyUSB0 cat boot.py
+```
+
+> I added `delay` of 2 seconds because I had problems with executing commands.
+
+### rshell
+
+Even though `ampy` is a cool tool I opted with `rshell` in the end since it's
+much more polished and feature rich.
+
+```bash
+# installing ampy
+sudo pip3 install rshell
+```
+
+Now that `rshell` is installed we can connect to the board.
+
+```bash
+rshell --buffer-size=30 -p /dev/ttyUSB0 -a
+```
+
+This will open a shell inside bash and from here you can execute multiple
+commands. You can check what is supported with `help` once you are inside of a
+shell.
+
+```bash
+m@turing ~/Junk/esp8266-test
+$ rshell --buffer-size=30 -p /dev/ttyUSB0 -a
+
+Using buffer-size of 30
+Connecting to /dev/ttyUSB0 (buffer-size 30)...
+Trying to connect to REPL  connected
+Testing if ubinascii.unhexlify exists ... Y
+Retrieving root directories ... /boot.py/
+Setting time ... Sep 06, 2020 23:54:28
+Evaluating board_name ... pyboard
+Retrieving time epoch ... Jan 01, 2000
+Welcome to rshell. Use Control-D (or the exit command) to exit rshell.
+/home/m/Junk/esp8266-test> help
+
+Documented commands (type help <topic>):
+========================================
+args    cat  connect  date  edit  filesize  help  mkdir  rm     shell
+boards  cd   cp       echo  exit  filetype  ls    repl   rsync
+
+Use Control-D (or the exit command) to exit rshell.
+```
+
+> Inside a shell `ls` will display list of files on your machine. To get list
+> of files on flash folder `/pyboard` is remapped inside the shell. To list files
+> on flash you must perform `ls /pyboard`.
+
+#### Moving files to flash
+
+To avoid copying files all the time I used `rsync` function from the inside of
+`rshell`.
+
+```bash
+rsync . /pyboard
+```
+
+#### Executing scripts
+
+It is a pain to continuously reboot the device to trigger `/pyboard/boot.py` and
+there is a better way of testing local scripts on remote device.
+
+Lets assume we have `src/freq.py` file that displays CPU frequency of a remote
+device.
+
+```py
+# src/freq.py
+
+import machine
+print(machine.freq())
+```
+
+Now lets upload this and execute it.
+
+```bash
+# syncs files to remove device
+rsync ./src /pyboard
+
+# goes into REPL
+repl
+
+# we import file by importing it without .py extension and this will run the script
+> import freq
+
+# CTRL+x will exit REPL
+```
+
+## Additional resources
+
+- https://randomnerdtutorials.com/getting-started-micropython-esp32-esp8266/
+- http://docs.micropython.org/en/latest/esp8266/quickref.html