Media - raspberry pi - Page 1

My sensor-activated Raspberry Pi e-ink display setup for the back room is aliiiive! 🎉 AND I managed to write the Raspberry Pi code fully in Python as well. 💪🏻

The ESP32 polls the distance sensor every 50ms and checks to see if the distance read is less than a given threshold (the distance from sensor to floor is about two metres, so I set the threshold to trigger at 1.5m so it'll go off if someone walks through the doorway). If the threshold is breached, it'll send a message to an MQTT topic with a payload indicating that the sensor was triggered and will not send any more messages even if the sensor is triggered again within a user-specified period of time. Once that same user-specified period of time has passed with the distance threshold NOT being breached, it'll send another message to the MQTT topic saying the sensor is no longer triggered.

On the Raspberry Pi side of things, my Python code listens to the MQTT topic that the ESP32 is publishing to, and if it receives a "triggered" message, it checks to see if the display is already on and being updated and will turn it on and start updating every minute if not. Once it receives a "not triggered" message, it'll clear the display so it's effectively "off".

In the video, I set the trigger ignore period to ten seconds which is why it turns back off so quickly, but in ordinary use I have it set to an hour.

I am by no means a professional Python developer, but if you're curious, the code is on Codeberg (ESP32 and Raspberry Pi)).

Posted on 7 January 2025, 14:08

A photo of the box of the Dune 2 Blu-ray and a Pimoroni "HyperPixel" four-inch display, plus the new temperature sensor which consists of a coiled black cable with almost what looks like a silver microphone cover at the end of it where the sensor lives.

New goodies! Dune Part 2 in 4K HDR, a replacement screen for one of our Raspberry Pi-attached dashboards, and a different type of temperature/humidity sensor, the Sensiron SHT-30, that's actually got a weather-proof mesh around it and is specifically designed for outdoor usage.

(Our current BME280 it turns out is not, and despite being protected from direct rain, the humidity after it rains gets high enough that the sensor gets saturated and all the readings end up being wrong. I also found out that you can actually calculate the dew point if you have the temperature and relative humidity so I don't even need the BME280 to do that for me! The only thing that I'll be missing is the atmospheric pressure, I COULD leave the BME280 attached for just that but but I don't actually know that I care all that much about it tbh.)

our house raspberry pi darkroom esp32 dune

Posted on 21 August 2024, 14:35

A photo of the box of a Raspberry Pi 4B+, a bare Pi Zero W, and power supplies and SD cards for the two.

So the other reason I've been learning how to use Ansible to set up our Raspberry Pis is because I wanted both easy software configuration AND to have backup hardware in case something died. I've fully automated the setup of the two Zero Ws at the front of the house and the 3B+ that runs our e-ink display in the office, the last thing remaining is the "main" 4B+ that runs the MQTT broker, dashboard hub, Powerwall usage-reader, Homebridge, and AirPort target that all the other Pis pull their data from. I ordered another 4B+ and Pi Zero W both for backup hardware and to be able to get the Ansible automation done without accidentally breaking "production" as it were, and it arrived today, woot.

As a side note, it never ceases to astound me how SMALL micro SD cards are!

our house raspberry pi darkroom

Posted on 20 June 2023, 20:21

I haven't done anything with the actual ESP32/physical button thing yet, but I got the software side of my "remotely turn the Raspberry Pi displays on and off" project done!

The core is a very simple Node.js service that runs on the Pis directly and subscribes to an MQTT topic that contains messages indicating whether the display should be on or off, then writes directly to the GPIO pin to control the display brightness. I updated my Pi Home Dashboard to add an HTTP endpoint that'll send messages to that same topic the display-attached Pis are subscribed to, and the shortcuts in the video are simply calling that endpoint.

I'm using the "retain" MQTT flag for the messages sent to the display status topic so even if the Pis reboot for whatever reason, the last known state is what they'll start up with again when they come up. And finally, instead of a cronjob set on each individual Pi to automatically turn the displays off at midnight and back on at 8am, I've got one running on the main Raspberry Pi 4B that runs the MQTT broker that just sends the required message to the MQTT topic and the Pis with the display attached dutifully turn on or off as necessary.

raspberry pi diy video

Posted on 11 September 2022, 11:36

A photo of a Mac mini on a small shelf with a Raspberry Pi next to it. The power LED on the Pi is emitting a REALLY deep rich red. Under the shelf are two external hard disks with blue LEDs in them, and to the left of them is a dubious-looking ceramic chicken. There's no light at all apart from what's coming from the LEDs.

I saw the red light from the Raspberry Pi glowing in the dark and figured it might make a neat Night Mode shot.

I wasn't wrong! This was the maximum 10 second exposure.

our house raspberry pi darkroom night mode

Posted on 29 July 2021, 23:39

A photo of a 4" LCD display sitting on a shelf, showing PM1.0, PM2.5, and PM10 values.

Got my little Raspberry Pi-powered air quality sensor and display up and running!

our house raspberry pi diy darkroom

Posted on 24 November 2020, 21:52

A photo of a small LCD display showing indoor and outdoor temperature, how much power we're consuming and producing from the solar panels, and the battery charge percentage. Next to the percentage is a green up arrow that indicates it's being charged, if it's discharging it changes to a red down arrow.

I have of course updated my little Pi display to pull data from the Powerwall, and added the battery charge percentage and whether it's charging or discharging. 😎

our house raspberry pi diy darkroom tesla powerwall

Posted on 30 October 2020, 9:45

A photo of a small e-ink display on a shelf showing the current outdoor and indoor temperatures, plus current power consumption and production in kilowatts.

Updated my Raspberry Pi e-ink temperature display to be easier to read, and it also now includes our power consumption and production!

our house raspberry pi diy photos.app

Posted on 14 May 2020, 13:05

A photo of a small e-ink display showing indoor and outdoor temperature and humidity, but the information is sized for the old 2" display and it looks very silly now.

Woohoo, the 2.7" e-ink display I ordered finally arrived! Now I just need to update my setup that feeds it information because it looks utterly ridiculous right now. 😂

our house raspberry pi diy photos.app

Posted on 12 May 2020, 13:06

A screenshot of the Home app in iOS showing three "cards", one for the HomePod and the other two saying "Outdoor Temperature" and "Indoor Temperature", with the current values for those.

HomePods are controlled via the Home app on iOS, which uses Apple's HomeKit. Someone wrote a Node.js service called Homebridge that lets you write your own plugins to show up in Home, so I did some coding and now have our Raspberry Pis that have the temperature sensors attached showing up right from within iOS! I'm going to write up a blog post going over how I got it all going in detail, because there was a LOT of trial and error.

raspberry pi screenshot ios homepod homekit

Posted on 10 April 2020, 11:20