Raspberry PI Pico (W)

NeoPixel / OLED clock with NTP

This page describes building and programming NeoPixel / OLED clock driven by NTP based on:

• Raspberry PI Pico W
• SSD1306 128x64 OLED display
• 24x RGB LED NeoPixel circle Ø65, WS2812B
• 24x RGB LED NeoPixel circle Ø85, WS2812B
• Optional microSD slot for storing WiFi config

Programming

I use Visual Studio Code for developing my Raspberry PI Pico projects. Setting up this powerful developing environment is described in this article But I using much simpler method on Windows: this complete package. It contains RP2040 Toolchain pro Windows - Pico-SDK, VSCode a CMake.

Installation directory structure

I have installed SDK in C:\PicoSDK. But workspaces I have in D:\Home\Development\Personal\PICO. If you encountered any problems with build, maybe you'l need manually enter some system variables:

Compiling C sources

Running CMake scripts

Debugging

For debugging Raspberry PI Pico is needed another Raspberry PI Pico :-). It's explained in this article.

Note that NeoPixels may not works in debugger due to timing issues.

Hardware

• For SSD1306 OLED display I use GP6 as SDA and GP7 as SCL. It's second I²C channel.
• NeoPixels uses GP14 and GP15.
• I'm not sure but SPI0 is probably used with CYW43439 wireless chip. So MicroSD card uses SPI1:
  • MISO = GP8.
  • MOSI = GP11
  • SCK = GP10
  • CS (Chip Select) = GP9
• There is switch to enable DST. One side is connected to GND via 10k pull-down resistor and GP12, other side is connected to 3.3V.

• Green LEDs are quarters of hour.
• Blue LEDs displays minutes. Because we have 60 mins per hour and only 24 LED's, smooth intensity transition is used for non-five minutes.
• Red LEDs displays hours. When we have more than 30th minute, next is lights on so all 24 ones is used.
• Both circles don't have LED0 aligned due to mounting holes shift. There is constant STRIP65_SHIFT that corrects it.
• OLED displays both UTC and local time - CE(S)T in my case. You have to modify displayTime function to change it.

WiFi configuration

There are two possible ways for WiFi configuration:

• In file CMakeLists.txt is WiFi configuration. So its necessary to change it and rebuild project. SD card is not needed in this case. You can comment out function readWiFiConfig.
• Use microSD card and store file wifi.txt with SSID (case sensitive!) at first line and password at second (followed by new line). Then you may use my picow_ntp_client_background.uf2

Download

GitHub .

If you use miroSD card for WiFi config, simply use picow_ntp_client_background.uf2.