Raspberry π

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  • Do any of you work in IT? These projects are cool and look satisfying but I feel so burned out with writing config files and plumbing bits together and browsing stack exchange at work that this kind of thing has no appeal when I get home

  • I do, and yeah, fighting with Linux is my day job so it's a bit of a pain to come home and have to do it just to get back on the internet. A PhD is particularly sapping though - wait until you're on a half decent salary and clocking off at 5 on the dot and you might find some motivation comes back :)

  • Yep mine too.

    I did wonder briefly yesterday evening why I was fucking about making an arduino powered mousetrap. I suspect it is because there are a million more useful things I could have been doing

  • I used to, but bit any more. It's nice to have geeking as a hobby not a day job.

  • might find some motivation comes back

    One can hope

  • Just you wait, I'm going to try to get it to start tweeting

    What, like that other pie hole ... now, what was his name again ... ?

  • https://twitter.com/jugglers_pi

    Temperature in my flat according to my Raspberry Pi. It is by the window, so maybe a few degrees colder than elsewhere. Eventually I'll set this to private so people can't watch it and figure out whether on holiday etc.

    Pi Hole/network is clearly fucky as it's supposed to be tweeting every hour, but there's 5 hour gaps. Will check the sys logs at some point...

  • Most likely a typo in your cron jobs.

    Try https://crontab.guru/

  • 24 * * * * /home/pi/temp.sh > /home/pi/.last_tweet.log 2>&1

    (Yes temp.sh is a terrible name, I meant "temperature" not "temporary")

    (Yes I know 24 means 24th minute, not 24 hours. I didn't want it to tweet on the hour in case there are other processes doing stuff then. 24 is just a random number.)

  • Interesting. Are the 5 hour gaps regular or just occasional?

    Can highly recommend Thingspeak for this sort of thing. I send it temp readings every 60 seconds and never skips a beat. It can also tweet for you.

  • Not regular, no. Sometimes it goes down for 1 hour, sometimes more. You can see overnight it was pretty stable except one hour. Most likely related to the other undiagnosed network issues I've been having...

    I like your temp. graph. Nice day/night contrast when you plot most of the day.

  • When I have some more time I'll pretty up the graphs and add some record monitoring.

    I'm using an ESP8266 to do the data logging to wifi. I can't believe how versatile these boards are. Less than a fiver too.

  • ESP8266

    Very interesting. I'll be looking for something to replace the Pi, as pihole and tweeting at the same time seems to stress the system a little bit too much. Would also not like my central heating to rely on the Pi given its flakiness - could end up being costly

  • Yeah, it sucks. I do the bare minimum to get this shit up and running and don't touch it.

    If it ain't broke... don't fucking adjust it!

  • Keep meaning to get around to hacking my home temp monitoring stuff.

    I want temp in 4 or 5 rooms using DS18B20's (although some rooms will be treated to a Honeywell HIH-4031 or similar humidity sensor as a bonus). All running back to a RPi or a ESP8266 so it can be scraped, stored on the NAS and graphed at my leisure.

    Then I'll add another temp/humidity sensor for the outside world and also a few DS18B20's ziptied to radiator pipes in various rooms and possibly the HW and CH outlet pipes of the boiler to keep an eye on the heating system.

    But, yes, working with computers all day long does sap my motivation somewhat. I've got a huge list of home projects and this list only ever seems to grow.

  • I'd really recommend going down the Iot4.eu route for this. Buy 4 or 5 of their wifi temp sensors, and they will do all the logging for you automatically to thingspeak including graphing and csv extracts of your data.

    The IOT4 sensors use DS18B20 as their thermocouple.

  • */10 * * * * ping -qc3 google.com >> /whatever/ping.log 2>&1

    Maybe try this to get visibility on your network connectivity?

  • Iot4.eu

    Interesting but moneygun.gif

    That'd be close to 300EUR for what I want to do (and not much cheaper if I didn't worry about humidity). I like the idea of monitoring barometric pressure too, will add one of those to my list for the outside monitor.

    Humidity sensors aside, I was planning on spending about 30EUR on the lot (already have a spare RPi to act as the 1-wire host). A bunch of DS18B20's, a 100m reel of 3 core cable, some heatshrink, zipties and a lot of swearing. Also means I don't use up a power socket or two in each room I want to monitor anything in. For now I was just going to isolate and remove the existing alarm system (we've long since disabled it) as it has a bunch of 3-core cables going to various most corners of the flat.

    If we ever get this flat rewired then apart from Cat 6 everywhere I'd also spec out a proper 1-wire architecture at the same time, that would simplify things a lot if the cables were already in the walls all going back to a central point.

  • Oh wow, you're planning on running cables to all the sensors? That'd totally put me on edge!

  • While I remember, anybody wanting to wirelessly monitor temperature could do a lot worse than buying a Garmin Tempe sensor. A single CR2032 lasts about a year in my experience. You need to have a phone or PC with ANT+ support and some basic BLE toolkit skills though.

  • Ideally there'd be something both wireless and battery powered that could do it all (like the Tempe but with Humidity and Pressure) but I don't want to be changing batteries in things all the time - and non-rechargeable batteries aren't great for the environment.

    I did wonder about using a bunch of Pi Zero powered using PoE but since there's no ethernet wiring in the walls of the flat that's not a goer. If I'm running cables then they may as well be a big passive 1-wire loop.

    Even those IoT4.eu sensors need power and have a cable running to the thermocouple so there's some form of wiring already. The main reason for not using them is that I generally want two temperature sensors in each room, one for air temp and one for radiator pipe temp. Paying another EUR29 just for an extra temp sensor is a bit much.

    If I was able to splice in a second DS18B20 of my own into the wire and the system was capable of dealing with this then the price (including the humidity sensor) would actually be quite reasonable.

    The electronics and backend coding bits don't bother me, one of the previous projects was a RPi that would scrape the TFL live bus website and display the time and when the next local bus was due outside our house (it only goes once every half an hour). The Pi ZeroSeg module needed to be soldered together, which is less fun with lead-free sodder solder. One of the buttons would make it cycle through the buses due at the end of the road (Putney Hill), the other button would make it display a silly message for my daughter.

    (I think I used a PiZero for that hence the separate Wifi dongle. Using a PiZeroW would mean I can get rid of that bit.)

    I was going to place it in the hall by the front door where the existing alarm keypad is (and I can use the existing alarm cables to provide the 5V USB power for the Pi).

  • What do you mean about the 1-wire loop? Is it some kind of electrical configuration for your home wiring?

    I love the raspberry pi poe hats, have used a load of them for work

  • What do you mean about the 1-wire loop? Is it some kind of electrical configuration for your home wiring?


    By "loop" I meant "linear" in the above doc. It's much simpler than attempting stubbed or star type networks.

    This is completely separate from mains electricity wiring, but if I get my flat rewired and can put whatever I want in my walls all coming back to a central location then I'll add Cat 6 back to a patch panel and also get the necessary cable put in for a separate 1-wire network (probably a star network).

  • I posted this in the iot thread, but seeing as there is some iot discussion here too i thought I'd double post:

    I have got the following items I would exchange for interesting craft ipa/sours/larger/stout, that might help you guys get going on some iot projects:

    Wemos d1 mini, new in packaging - swap for 1 bottle/can
    Wemos d1 mini, new in packaging - swap for 1 bottle/can
    Wemos d1 mini, opened and flashed with a bin file - free with any other item, or 1 bottle/can if you're feeling generous
    Nodemcu, new in packaging - swap for 1 bottle/can
    Raspberry pi zero w camera kit - swap for 3 bottle/cans
    Raspberry pi zero w camera kit - swap for 3 bottle/cans
    PhatDAC - swap for 1 bottle/can

    I also have some breadboards and jumper cables i can throw in if you take the lot!

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Raspberry π

Posted by Avatar for photoben @photoben