Linear Stepper Motor Gauge

a full 1 metre range for the data visualisation. It uses a stepper motor for precise needle movement, and a limit switch for calibration, it can be adapted to any MQTT data feed and any base mount. The example shown uses a 5cm by 10cm peice of wood, cut to 1 metre length and indicates wind speed from 0 to 60 mph.

The design uses a stepper motor (like the 28BYJ-48) which offers high-precision, 360-degree movement without the jitter or limited range of a standard servo. The limit switch allows the gauge to “home” itself on startup, ensuring the pointer always starts at a known zero position.

The main code – WindStepperTimerBeltwithLimitSwitch.ino in the Github has a distance calibration number, adjust for your range.

Hardware Components

• Arduino-compatible Board: Any board like an Arduino Uno, Nano, or a NodeMCU.
• Stepper Motor: 28BYJ-48 5V stepper motor.
• Stepper Driver: ULN2003 driver board (which often comes with the 28BYJ-48).
• Limit Switch: A small microswitch to detect the pointers zero position.
• Power Supply: USB.
• Timer Belt GT2 Timer Belt

It is made to be as simple to build/power as possible but also adatable for a number of senarios.

The github provides the mount for the stepper motor, the pointer (which also joins together the timing belt) the limit switch and the end mount for the pulley. These allow the gauge to be adapted to any size required.

At the moment the gauge is sitting on the wall in our lounge and it has become one of our most used guages. The data updates every minute to show the maximum wind gust and due to the nature of the stepper motor, it provides a smooth movement, almost replicating the gust of wind.

The post Stepper Motor Linear Data Gauge appeared first on Digital Urban.

The light simulates an oil lamp by staying “steady” for a random period and then “flickering” for a short time by rapidly dimming and brightening – the flicker speed changes acording to the wind speed. The full code and details are available on Github as part of the ever growing Open Gauges Project.

Ships Lamp

Features

• Real-time Data: Connects to an MQTT broker to subscribe to a wind speed topic.
• Weather Map Gradient: Displays wind speed using an intuitive “weather map” color gradient:
  • 0 mph: Off (Black)
  • 1-10 mph: Solid Green
  • 10-20 mph: Fades from Green → Yellow
  • 20-30 mph: Fades from Yellow → Orange
  • 30-40 mph: Fades from Orange → Red
  • 40+ mph: Solid Red
• Realistic Flicker Effect: The light doesn’t just stay solid; it cycles between a “steady” phase (10-60s) and a “flicker” phase (5-15s) to simulate a real lamp.
• Asynchronous & Resilient: Built using uasyncio and mqtt_as. The mqtt_as library automatically handles and recovers from WiFi or MQTT broker disconnections, re-subscribing to topics as needed.
• Hardware Watchdog: Uses the Pico’s built-in machine.WDT (Watchdog Timer) to automatically reboot the device only if the main code loop freezes, ensuring high reliability. (This replaces the old 60-minute timer).
• Status LEDs: Provides a heartbeat flash on one LED and a WiFi status indicator on another.

Hardware Requirements

• Raspberry Pi Pico W: (or any Pico with a WiFi-capable board).
• NeoPixel LED Strip: The code is configured for a strip, but can be any WS812B/NeoPixel compatible LEDs.
• Power Supply: A sufficient power supply for your LED strip (a strip of 60 LEDs can draw several amps at full brightness).
• A Ships Lamp (old or new).

Default Pinout (Pico W)

• NeoPixel Data: GP15
• Blue LED (Heartbeat): blue_led (defined in config.py, often the onboard LED).
• WiFi LED: wifi_led (defined in config.py).

Software & Dependencies

This project relies on a few key MicroPython libraries that you must have on your Pico:

1. neopixel.py: The standard Adafruit NeoPixel library for MicroPython.
2. mqtt_as.py: A robust, asynchronous MQTT client. You can find it here.
3. config.py: A file you must create to hold your credentials and pin definitions.

Configuration

You must create a config.py file in the root of your Pico’s filesystem. This file should contain:

1. Your WiFi and MQTT broker credentials.
2. Definitions for your wifi_led and blue_led.

The mqtt_as library expects the config.py to contain a config dictionary.

Example config.py:

# config.py
from machine import Pin

# --- WiFi Configuration ---
config['wifi_led'] = Pin("WL_GPIO0", Pin.OUT) # Onboard LED on Pico W
config['ssid'] = 'YOUR_WIFI_SSID'
config['wifi_pw'] = 'YOUR_WWIFI_PASSWORD'

# --- MQTT Configuration ---
# This example is for the open broker mqtt.cetools.org
config['server'] = 'mqtt.cetools.org'
config['port'] = 1884
config['client_id'] = 'pico_ships_lamp' # Or any unique ID

# --- Optional: For Secured Brokers ---
# If your broker requires a username and password, add these lines:
# config['user'] = 'YOUR_MQTT_USER'
# config['password'] = 'YOUR_MQTT_PASSWORD'

# --- Other Hardware ---
# This is for the heartbeat LED
blue_led = Pin(10, Pin.OUT) # Example: an external LED on GP10

Running the Project

1. Upload main.py, neopixel.py, mqtt_as.py, and your config.py to your Raspberry Pi Pico.
2. Reset the device.
3. The device will automatically connect to your WiFi and MQTT broker.
4. It will subscribe to the topic personal/ucfnaps/downhamweather/windSpeed_mph.
5. As messages are published to that topic, the ship’s lamp will spring to life!

Customizing

• LED Count: Change the numpix variable at the top of main.py to match your strip.
• Data Pin: Change the 15 in pixels = Neopixel(numpix, 0, 15, "GRB") to match your data pin.
• MQTT Topic: Change the a topic name in the conn_han function to subscribe to your own data source.

The post Ships Lamp Wind Speed Gauge appeared first on Digital Urban.

There are many tutorials online on using an LED Matrix to display data—many of them require wiring up a screen, external power supplies, or flashing boards. We wanted to highlight a slightly more accessible way to get an LED Matrix—in our case, a Hub 75, 32×64 pixel up and running using an Interstate75W from Pimoroni. The benefit of the Interstate is that it plugs indirectly into the matrix and can power a single screen directly from the board.

Interstate75W

We wanted a way to display any data we wanted on the screen with the screen lighting up and data scrolling up as it arrives and then turning off. To use this we use MQTT to load our data (a test feed is included in the scripts – which displays Time, News and Environmental Information) – see below for a demo:

 

We also incorporate manual brightness control and reconnecting for the MQTT for message handling, making it easy to update the display from anywhere. Setting up your own MQTT is beyond this post, but its easier than you may think and once you have one it can be used to display any data, from external feeds such as weather apis through to data from systems such as Home Assistant. Edit April 2025, we have added additional files to allow use with the new Pimoroni Intersate Starter Kit 128×128 Matrix, allowing a larger format screen, as pictured below.

Matrix128x128

Features

• Scrolling Text Messages: Display messages that scroll across the HUB75 LED matrix.
• Manual Brightness Control: Adjust the brightness of the display manually.
• MQTT Integration: Receive and display messages via MQTT.

Hardware Requirements

To get started, you’ll need the following hardware:

• Pimoroni Interstate75W
• A HUB75 LED matrix display
• 3D Printed Case
• MQTT broker (local or cloud-based) – we provide our own feed so you can test the set up.

There is also room in the 3D printed case to attach a cloth cover, acting a diffuser (a grey t-shirt works well, cut to size):

LED Matrix with Cloth Cover

Software Requirements

You’ll also need the following software – all available from our GitHub

• MicroPython
• Required MicroPython libraries:
  • interstate75
  • mqtt_as
  • uasyncio

Setup

1. Clone the Repository

First, clone the project repository from GitHub, or just download the files directly:

“`sh
git clone https://github.com/digitalurban/Interstate75W_MQTT_Scroller
cd interstate75w-mqtt-display
“`

2. Upload the Code

Next, upload the code to your microcontroller. You can use tools like Thonny or ampy to do this.

3. Configure WiFi and MQTT

Update the config.py file with your WiFi credentials, the MQTT details can also be updated if you have your own server, if not then leave them for our demo feed.

“`python
config = {
‘ssid’: ‘your_wifi_ssid’,
‘wifi_pw’: ‘your_wifi_password’,
‘server’: ‘mqtt_broker_address’,
‘user’: ‘mqtt_user’,
‘password’: ‘mqtt_password’,
‘port’: 1883,
‘keepalive’: 60,
}
“`

Usage

Run the Script

The script will automatically connect to WiFi and the MQTT broker, then start displaying messages – our MQQ feed displays messages approximatly every 3 minutes.

Constants and Initial Setup

The script defines constants for controlling the scrolling text speed, how long the screen says on for after displaying the message and brightness settings. It also initializes the Interstate75W object:

Constants for controlling scrolling text

BACKGROUND_COLOUR = (0, 0, 0) # Black background to turn off the screen
HOLD_TIME = 2.0
BLANK_SCREEN_TIME = 10.0
BUFFER_PIXELS = 2 # Increased buffer to ensure full scroll off
SCROLL_SPEED_LEVEL = 8 # Set the desired scrolling speed level (1 to 10)
SCROLL_SPEED = 1 / SCROLL_SPEED_LEVEL # Convert to a delay in seconds

Brightness settings

brightness = 50 # Initial brightness (0 to 100)

Do let us know if you make one – we would love to see images of your own set up and we hope this made it a little easier for anyone new looking to run an LED matrix using MQTT.

The post Make a Scrolling Hub75 Matrix Display using a Pimoroni Interstate75W and MQTT appeared first on Digital Urban.

The post Open Gauges – Physical and Digital Data Display Devices appeared first on Digital Urban.

You can read the paper via – Lovett, Leah & Hay, Duncan & Hudson-Smith, Andy & Jode, Martin. (2020). Mobile Communications Technologies in Tree Time: The Listening Wood. Leonardo. 54. 1-2. 10.1162/leon_a_02006.

The post Mobile Communications Technologies in Tree Time: The Listening Wood  appeared first on Digital Urban.

You can download the paper at – Hudson-Smith, A., Wilson, D., Gray, S., Dawkins, O. (2021). Urban IoT: Advances, Challenges, and Opportunities for Mass Data Collection, Analysis, and Visualization. In: Shi, W., Goodchild, M.F., Batty, M., Kwan, MP., Zhang, A. (eds) Urban Informatics. The Urban Book Series. Springer, Singapore. https://doi.org/10.1007/978-981-15-8983-6_38

The post Urban IoT: Advances, Challenges, and Opportunities for Mass Data Collection, Analysis, and Visualization appeared first on Digital Urban.

The post The Little Book of Public Space and the Internet of Things appeared first on Digital Urban.

The YouTube clip below details the collection so far (Spring 2021):

Each of these objects will be explored further and made available to print, insert into 3D worlds and view online. One such example is our ‘THE’ – Time, Headlines and Environmental Data.

We have a full tutorial on making a ‘THE’ over at Connected Environments. A more recent addition is the ability to upload models to SketchFab and make them available to download.

SketchFab also allows models to be embed and viewed directly within a web browser – below is an example of our 3D Printed Barograph, using realtime data feeds combined with more traditional paper and ink to recreate the Barograph – click ‘Play’ to view the model in 3D.

We will be posting more about the Spring 2021 collection in the coming weeks. Its been a while since our last post over here on Digital Urban, it is good to be back.

The post IoT 3D Printable Devices – The Spring 2021 Collection appeared first on Digital Urban.

Radio linked to Philips Hue

The post Linking a 1940’s Radio to the Internet of Things appeared first on Digital Urban.

Philips Hue

Netatmo Weather Station

We are using the Netatmo in CASA as part of our forthcoming office data dashboard, it monitors internal temperature, humidity, sound levels and carbon dioxide with an external unit providing temperature and humidity readings.

Colour Range

If This Then That Recipes

Ships Lamp Coloured by Temperature and IFTTT

The post IFTTT, Netatmo & Philips Hue: Linking Data to Lighting appeared first on Digital Urban.