Raspberry Pi Pico with ws2812 LED string, SSD1306 OLED display, esp8266 (esp-01), and 24LC512 EEPROM. "Christmas Lights"

Image of project // still a WIP

Description

This project was designed for a decorative Christmas tree made out of cedar which stands about two feet in height. It consists of a Raspberry Pi Pico, a string of ws2812 neopixels, a 128x64 pixel (model: SSD1306) OLED display, an EEPROM (model: 24LC512), a standard push-button, and a esp8266 esp-01 module. The string of lights serve as the lights on the wooden Christmas tree and are controlled by one wire sending data in series to the lights. each new received value pushes the previous down the line to the next light. The different patterns of the lights are cycled through by pressing the push-button. The OLED display communication protocol is SPI and this display is used to give feedback to the user in form of the name of the LED string lighting style name. The time will be displayed after no button activity has occurred in a certain number of seconds (TBD). The time is obtained by using the esp8266 module to connect to the internet through the LAN wifi and obtain the time from a time server. Each time the led string lighting style changes, the array index of that style is stored in the EEPROM so that on next start up that setting is immediately recalled and used. I2C protocol is used to talk to the EEPROM. There is also a standalone LED that indicates whether wifi is connected or not (red/green common cathode LED).

Prerequisites

The following classes (which are all in this repo) must be manually loaded onto the pico for this project to work:

• base64.py
• EEPROM_24LC512.py
• esp8266.py
• httpParser.py
• image_utils.py
• neopixel.py
• ssd1306.py
• main.py

Installing / Updating

The tools/ directory contains one-shot installer scripts for Windows (install.bat) and macOS (install.sh) that handle everything from a completely bare machine — no git, Python, or anything else required. They install all dependencies, clone the repo, flash the correct set of files to the Pico via mpremote, and uninstall everything they added when done.

# Windows
tools\install.bat              # LEDs only (no wifi/clock)
tools\install.bat --wifi       # full firmware with wifi + NTP clock
tools\install.bat --pineapple  # pineapple LED layout

# macOS
tools/install.sh               # LEDs only (no wifi/clock)
tools/install.sh --wifi        # full firmware with wifi + NTP clock
tools/install.sh --pineapple   # pineapple LED layout

See tools/README.md for full details on what each flag does, which files get uploaded, and how the wifi credential flow works.

Flashing MicroPython firmware (brand new Pico)

Skip this section if the Pico already responds as a serial/COM port — it already has MicroPython.

1. Download the latest MicroPython .uf2 for the RP2040 from https://micropython.org/download/RPI_PICO/
2. Hold the BOOTSEL button on the Pico, plug it into USB, then release the button.
3. It mounts as a drive called RPI-RP2 — drag and drop the .uf2 file onto that drive.
4. The Pico reboots automatically and is now running MicroPython. It will show up as a serial/COM port instead of a drive.

Once you see the COM port you're ready to use mpremote or run the installer scripts in tools/.

Upload a single file to the Pico

The Pico must already be running MicroPython (shows up as a COM port, not as the BOOTSEL drive).

pip install --user mpremote
python -m mpremote cp main.py :main.py + reset

Swap main.py for whichever file you want to overwrite. The + reset soft-resets the controller immediately after the copy so the new code takes effect. python -m mpremote ls lists what's on the device.

To delete a file:

python -m mpremote rm :neopixel.py

To dump the contents of a file to the terminal:

python -m mpremote exec "print(open('main.py').read())"

Text Image Creation

1. open paint and set the properties canvas size to the number of pixels on the display (128,64)
2. add some text with cool font and different size as well as bold and get it centered in the canvas
3. select all (ctrl+a) then right click the image and invert colors
4. save the image to a place easy to get to
5. got to https://javl.github.io/image2cpp/ and open the image from the previous step
6. convert it and then use the *_img files in this proj as a template on how to use that data

TODO

• use various waveforms to mask the brightness of the strip... i.e. cos, tan, sawtooth, triangle
• similarly to above, mask the waveforms along the time domain

USE THONNY TO WRITE THE FOLLOWING CODE TO PI PICO WHICH IS CONTROLLING ESP8266-01

from machine import UART, Pin
user_agent="RPi-Pico"
host="worldtimeapi.org"
path="/api/timezone/America/New_York"
getHeader = "GET "+path+" HTTP/1.1\r\n"+"Host: " + host+"\r\n"+"User-Agent: "+user_agent+"\r\n"+"\r\n"
txData = "AT+CIPSEND="+str(len(getHeader))+"\r\n"
UART_Tx_BUFFER_LENGTH = 1024
UART_Rx_BUFFER_LENGTH = 1024*2
UART_BAUD = 115_200
uart_port = 1
uart_tx_pin = 4
uart_rx_pin = 5
esp = UART(uart_port, baudrate=UART_BAUD, tx=Pin(uart_tx_pin), rx=Pin(uart_rx_pin), txbuf=UART_Tx_BUFFER_LENGTH, rxbuf=UART_Rx_BUFFER_LENGTH)
esp.write('AT\r\n'); esp.read()
esp.write('AT+GMR\r\n'); esp.read()
esp.write('ATE1\r\n'); esp.read()
esp.write('AT+GMR\r\n'); esp.read()
esp.write('AT+CWMODE_CUR=3\r\n'); esp.read()
esp.write('AT+CWJAP_CUR="<YOUR_SSID>","<YOUR_PASSWORD>"\r\n'); esp.read()
esp.write('AT+CIPSTATUS\r\n'); esp.read()
esp.write('AT+CIPSTART="TCP","worldtimeapi.org",80\r\n'); esp.read()
esp.write('AT+CWLIF\r\n'); esp.read()
esp.write('AT+HTTPCLIENT=1,0,"http://httpbin.org/get","httpbin.org","/get",1\r\n'); esp.read()
esp.write('AT+CIPSTART="TCP","worldtimeapi.org",80\r\n'); esp.read()
esp.write("AT+CIPSEND="+str(len(getHeader))+"\r\n"); esp.read()
esp.write(getHeader); esp.read()
esp.write("AT+PING=\"google.com\"\r\n"); esp.read()
esp.write("AT+PING=\"8.8.8.8\"\r\n"); esp.read()
esp.write("AT+CWJAP?\r\n"); esp.read(); esp.read()
esp.write("AT+CWQAP\r\n"); esp.read(); esp.read()