uploaded testing micropython on an ESP8266 D1 Mini.md

Author: alifeee

notes/testing micropython on an ESP8266 D1 Mini.md

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+---
+title: testing micropython on an ESP8266 D1 Mini
+date: 2025-03-13
+tags:
+- MicroPython
+- microcontrollers
+---
+I've toyed for a while with microcontrollers, and only really used Arduino/C/C++. Sometimes, I've heard talk of MicroPython, but I've never tried it out.
+
+Until today!
+
+I had a little experiment, and it seems promising. I might have a larger experiment soon (maybe try to retry some of my [hardware hacking](https://alifeee.co.uk/favourites/#hardware%20hacking)).
+
+I'll share here my initial experiments! I'm running on a Linux computer, on Pop!\_OS.
+
+I read the:
+
+- installation guide: <https://www.wemos.cc/en/latest/tutorials/d1/get_started_with_micropython_d1.html>
+- usage guide: <https://docs.micropython.org/en/latest/esp8266/quickref.html>
+- web-REPL help guide: <https://docs.micropython.org/en/latest/esp8266/tutorial/repl.html>
+- D1 Mini pinout reference: <https://i0.wp.com/randomnerdtutorials.com/wp-content/uploads/2019/05/ESP8266-WeMos-D1-Mini-pinout-gpio-pin.png>
+
+…and downloaded the firmware file for the ESP8266 D1 Mini (which I have a few of) from <https://micropython.org/download/ESP8266_GENERIC/>, and then ran:
+
+```bash
+# install files and virtual environment
+mkdir -p /git/micropython
+cd /git/micropython
+python -m venv env
+. env/bin/activate
+pip install esptool
+
+# download firmware
+$ ls
+ESP8266_GENERIC-20241129-v1.24.1.bin
+
+# at this point I plugged in the ESP but it was not recognised
+#   after looking at `tail -f /var/log/syslog`, I saw that `brltty`
+#   was doing something spooky. I remembered having this issue before,
+#   and that `brltty` was something to help Braille readers. As I don't
+#   need that, I...
+# disabled brltty
+sudo systemctl stop brltty.service
+sudo systemctl mask brltty.service
+sudo systemctl disable brltty.service
+sudo systemctl restart
+
+# now I could see the ESP as a USB device
+$ lsusb
+$ ls /dev/ | grep "ttyUSB"
+ttyUSB0
+
+# flash ESP
+esptool.py --port /dev/ttyUSB0 erase_flash
+esptool.py --port /dev/ttyUSB0 --baud 1000000 write_flash --flash_size=4MB -fm dio 0 ESP8266_GENERIC-20241129-v1.24.1.bin
+```
+
+That's it installed! Now, using the guides above I found I needed a terminal emulator, so I used `picocom`. And, to reach the pinnacles of complexity, tried turning the inbuilt LED on and off.
+
+```bash
+sudo apt install picocom
+picocom /dev/ttyUSB0 -b115200
+>>> from machine import Pin
+>>> p = Pin(2, Pin.OUT)
+>>> p.off()
+>>> p.on()
+```
+
+It works! Neat! The REPL (Read-Evaluate-Print-Loop) is really nice to quickly debug with. Perhaps nicer than the "waiting-for-20-seconds-for-your-C-code-to-flash-onto-the-device".
+
+I also tried connecting to WiFi and using the Web-REPL, so you can execute Python commands over the air! With...
+
+```bash
+import network
+wlan = network.WLAN(network.WLAN.IF_STA)
+wlan.active(True)
+wlan.scan()
+wlan.isconnected()
+wlan.connect("ssid", "key")
+# wait a bit
+wlan.isconnected()
+# or use function from https://docs.micropython.org/en/latest/esp8266/quickref.html#networking
+```
+
+Then you can configure `webrepl` with:
+
+```bash
+import webrepl_setup
+```
+
+…and it will print out an IP that you can connect to and use the REPL from your browser! Very nice.
+
+What I haven't tried yet is using `boot.py`. From what I know it will execute on every reset of the ESP, so basically is how you "program" it, but a lot quicker, since you just place a file on the filesystem.
+
+I'll give that a go soon...