ESP8266

General

• Developing for ESP32/8266 on Windows using the Linux subsystem(WSL) from 2019
• How to Connect ESP8266 to WiFi | A Beginner’s Guide
• MobaXterm for serial communication with REPL
• Use ampy ampy to manipulate files on the board's internal filesystem and run scripts.
  • pip install adafruit-ampy
  • Can't use ampy while also simultaneously having a (MobaXTerm) serial communication (REPL) open

C-based development

• Expressif Developer Zone
• ESP8266 RTOS Software Development Kit

Wemos Mini D1 Setup with MicroPython

• D1 Mini docs

1. Install CH340 driver
2. Install Python on Windows by opening a PowerShell and typing Python, which will bring you to the app store. You may need to edit your powershell profile file to add python installed scripts path to $Env:Path.
3. pip install esptool
4. download MicroPython Firmware for Generic ESP8266 module
5. Make sure a new COM device shows up in Windows Device Manager
6. Install MobaXterm and Connect with baudrate 115200

D1 Mini V2 ESP-12F Wiki

• ESP8266 D1 Mini V2 ESP-12F WiFi Module - from protosupplies.com - $4.95
• ESP8266EX datasheet
• Operating current 80mA
• Power management
  • Active mode
  • modem-sleep mode
    • wifi off (15 mA)
    • esp.sleep_type( esp.SLEEP_MODEM )
  • light-sleep mode
    • CPU paused.
    • Wake up events will wake up the chip.
    • Maintaining a sleep of 300 ms with a wakeup of 3ms to receive AP’s Beacon packages at interval requires about 0.9 mA.
    • machine.idle() - return the amount of time that it slept before receiving a wake-up signal from one of the peripherals.
    • machine.lightsleep([time_ms])
  • deep-sleep mode
    • Only real-time-clock is on.
    • Sleep for 300s and wakes up to connect to AP (20 uA)
    • machine.deepsleep([time_ms])
• Use as WiFi adapter chip slaved to other MCU
• Clock speed 80/160 MHz (120MHz ATSAMD51 M4)
• 3.3V
• 4MB Flash
• 64kB instruction RAM
• 96kB Data RAM (half of ATSAMD51 M4)
• Build-in led is is board D4
  • Corresponds to ESP board pin2. (See dev board docs for board to chip correspondance)
  • Can't activate while using REPL
  • Write the following code to main.py, then ampy -p COM6 put .\main.py

import machine
import time
pin = machine.Pin(2, machine.Pin.OUT)
for i in range(10):
    pin.on()
    time.sleep(0.5)
    pin.off()
    time.sleep(0.5)

esptool

• esptool.py -h
• esptool.py read_mac
• esptool.py --port COM6 erase_flash
• esptool.py --port COM6 --baud 460800 write_flash --flash_size=detect 0 .\esp8266-20200911-v1.13.bin

MicroPython

• MicroPython quickref for 8266
• General info about esp8266 port
• Full MicroPython tutorial for ESP8266

Program the board via boot.py and main.py

1. pip3 install --upgrade adafruit-ampy
2. ampy -p COM6 get boot.py
3. ampy -p COM6 put main.py

FYI/Nifty features

• Minimizethe creation and destruction of objects to avoid fragmentation of the heap
• micropython.const() - declare a const so compiler can optimize it
• micropython.mem_info(verbose=True)
  • T = tuple
  • L = list
  • D = dictionary
  • S = string
  • A = array or bytearray
  • F = float
  • B = function
  • M = module
  • h = some other value, like an integer or python object
  • equals sign means the memory chunk continues (single allocation from heap)
• framebuf.FrameBuffer - The FrameBuffer class provides a pixel buffer which can be drawn upon with pixels, lines, rectangles, text and even other FrameBuffer’s. It is useful when generating output for displays.

WebREPL

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