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Pi Lab: top posts

The most useful posts in this topic, by likes from the community.

Posts

  1. Article

    Four Pi 5s, one k3s cluster: full build log, what went wrong, and why I'd buy a mini PC next time

    G'day legends. This took three weekends, two trips to Jaycar and one very long conversation with the wife about "what exactly is a control plane". Years ago Jeff Geerling's Pi Dramble videos put the idea in my head and it never left, so if you've not seen the original, start here: This is the full log. Every command I ran, everything that went wrong, and at the end an honest answer to "should you build one". Parts…

    Matt O'Brien114likes35comments

  2. Article

    I deleted a comment today and I'm not sorry: mains voltage is not a beginner project

    Normally I'm the bloke laughing at his own failures on here. Not today. Today someone posted (in a comment on another thread, I've removed it and messaged them, they were very good about it) a build where a cheap relay module sitting on a breadboard switched a 2400W heater on and off. Live and neutral running through breadboard jumpers. No fuse, no earth, no enclosure, screw terminals exposed on the bench. They…

    Matt O'Brien43likes10comments

  3. Experience

    2 years of LoRa trough sensors on a dairy farm: what I stuffed up so you don't have to

    Kia ora. Not a programmer, just a dairy farmer in the Waikato who got sick of driving round on the quad every morning checking troughs. 400 cows, 28 troughs, 3 tanks. That run took me about an hour and a half before milking, every day, rain or shine. Two years ago I started teaching myself Arduino off YouTube. Now every trough and tank reports in over LoRaWAN and I get a ping on my phone if one is low. I've stuffed…

    Hamish Turner42likes11comments

  4. Article

    ESP32 battery sensor: from 4 days to about a year on one 18650. Real numbers, real mistakes

    My uncle has a coconut farm near Pollachi. He wanted soil moisture and temperature from 6 spots, every 10 minutes, on his phone. Easy, I said. ESP32, WiFi to the pump shed, MQTT, done. First version battery died in 4 days . This post is how it became about a year, with numbers, because "use deep sleep" is not an answer. Step 0: measure, don't guess You need two tools: A multimeter in series for the sleep current (µA…

    Karthikeyan S37likes12comments

  5. Experience

    Seven dead SD cards in two years. Here is what finally fixed it

    G'day legends. Went through the shed drawer on the weekend and counted seven dead microSD cards, all out of Pis that run 24/7. The weather station, the chook house door, the Pi-hole, the garage camera. Every one died the same way: fine for months, then one morning it boots read-only or doesn't boot at all. Parts I use now (AUD, roughly): second hand 120GB SATA SSD ($20 at the tip shop / marketplace), a USB 3 to SATA…

    Matt O'Brien29likes10comments

  6. Article

    I2C debugging with a ₹650 logic analyser: the 5 bugs I find every month

    Every month somebody at work or on WhatsApp says "the sensor is not detecting". Nine times out of ten it is one of these five. Before you change the library or the sensor, look at the bus. The tool The cheap 24 MHz 8 channel "Saleae compatible" clone, ₹650 online. With sigrok PulseView (free) it works very well: sudo apt install pulseview sigrok-firmware-fx2lafw Sample at least 4× the bus speed, I use 8 MHz for 400…

    Karthikeyan S26likes8comments

  7. Experience

    A retired banker's first Raspberry Pi: a weather station on my terrace in Chennai

    Dear friends, I retired two years ago after 34 years in the IT department of a public sector bank. I began with punched cards, spent most of my career with COBOL, CICS and DB2, and learned Java in my fifties because the bank said so. My grandson, who is 17, informed me last year that COBOL is "basically dead" and that I should learn Python. I informed him that COBOL processed his grandmother's pension this morning.…

    S. Ramanathan23likes10comments

  8. Experience

    The Pi Zero that cooked itself in my letterbox (and what lives in there now)

    G'day legends. This one's a confession. Last January I built a "you've got mail" notifier. Pi Zero 2 W, a reed switch on the letterbox flap, a magnet, a little Python script that pinged Home Assistant over MQTT. Took an arvo. Worked first go. Felt very clever. Then Brisbane did Brisbane. The letterbox is black powder-coated steel, faces west, and sits in full sun from about 1pm. I had the Pi logging vcgencmd…

    Matt O'Brien16likes7comments

  9. Article

    Pi-hole + Unbound on an old Pi 3B: my setup after 2 year, full config

    Hi all, this is my first long post here. My Pi 3B is the oldest thing in my homelab and still the most important, because when it is down the whole house have no internet and my wife know exactly who to blame :) Why Unbound and not only Pi-hole Pi-hole alone block ads, but it still forward every query to some upstream (Google, Cloudflare, or your ISP). My ISP DNS here sometimes is slow, and when I type a domain…

    Nguyễn Minh Hiếu16likes8comments

  13. Article

    Printing a Pi 5 case that actually breathes (and survives a garage in July)

    Hi all! This is the long version of a story that starts with a sad, droopy Pi case (my own (I'm the enclosure lady, I know)). In July my garage hit 38°C for a week. My Pi 5 lives out there running OctoPrint for the printers, in a case I printed in PLA two years ago. By the end of that week the lid had sagged in the middle like a hammock, and the Pi was throttling every afternoon. So I redesigned it properly, and…

    Gwen Albright10likes9comments

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