 Be gweithio'r tîm mwyaf o'r tîm. Mae'n gwneud i gynhyrchu'r tîm, ond mae'n golygu y gallwn gwaz i'w gwirio'r tîm. Felly, y gallwn gwirio'r tîm, ond mae'n gwneud i'r rhannu gwirio'r tîm. Felly, mae'r ysgol dŵr yn cyfrifio. Mae'n cyfrifio gyda'r cyfrifio, mae'r ysgol yw'r ysgol yn cyfrifio. Mae'r arferwad amser yn ysgol, mae'r ysgol ar gyferwad, ddwyain ma'wn ddoch chi'n gweld a'r rai ddlawn. Felly, mae'r yn teimlo 18 mlynedd ar y canoled. Mae'r amlwg yw'r teimlo yn ei ddop! Rydym yn gweithio'i licens. Mae'r yn ddoch chi hyn gwneud am ymddir i mi un i ar iciw. Mae llunog ffawr, bith cyfnodyniadau cwng digwydd. Rwy'n ffawr i chi'n gweld i chi i ffwyd i'ch wneud ein llunogau. For the benefit of people like me in that situation, they are essentially pushing notifications before the era of smartphones and so on. There are a couple of examples of pages on there. Those are both relatively modern. Both of them are ones that can be used on amateur paging networks, The one on the right is a recycled T-Mobile one, which would have seen commercial use at some point. Yeah, they're both relatively modern, they can do numbers and text, but yeah, mainly text is what we're concerned about for announcing talk schedules. I'll address the question of why, which I feel probably nobody's asking because of course the answer to why is always why not. It's a bit of fun. Yeah, the schedule just seemed like it's kind of a bit of fun way to use pages really. So technical stuff, so these pages, these use protocol called POXAG, which is something that came out of, said there, the post office code standardisation advisory group. A name is fitting of Ian Shartons. So yeah, this was a standard that came around in the early 80s for how to actually communicate to devices like this over the air with the intention that standardisation being able to just use one thing for many devices. Over the air it's essentially just FSK coding, which is just essentially binary encoding with two different frequencies offset from a carrier. Yeah, I've not got too much into details, plenty of better explanations than I can probably give. So DapNet is a paging network for radiometry use. Whilst it's for radiometry use, obviously there's no reason why you can't just have a pager and receive pages, for example for the EMF schedule because you're not actually putting anything to air. If you want to transmit a page, obviously you need the requisite licensing, but for receiving you're fine. So yes, paging since most of what you're doing is receiving, quite good for that. So DapNet itself, yes, it's essentially an orchestration and internet backhaul for paging transmitters. So you submit a request to an API, it says, yes, I will transmit this to whatever transmitters you wanted, and it will then send that out to the transmitters you requested. There's two main ways that you can use it, you can send what they call calls, I don't know where the terminology calls comes from, but it seems a bit odd. But essentially a page or a message to an individual, or you can send them to what they call rubrics, which are kind of the best way to put it, I guess sort of groups for more specialized interests. So for example, there's an EMF camp from rubric, which is where all of the event schedule has been going, and that's what you would use for messages that you want to have multiple, they're intended for multiple recipients. So, in terms of transmitters, what can you do? So just for trying it out and having a bit of a play, the MMDVM hotspot is a good option, they're relatively cheap, they're very available. If you've played with any digital voice modes, you might already have one, and in which case DapNet and HuxAgo are just another checkbox that you can tick to enable this. And yeah, they're fine for playing around with us, of trying it out, or personally, so if you just want something that works at home, for something a bit bigger, there's the option of doing the sort of pi plus radio, existing radio sort of transmitter. So the image there is, I think that's the Motorola GM 1200, it's one that I stole off the DapNet wiki. So yeah, this is just taking some software, in this case Unipagia, which I'll talk more on later, and yeah, you take the sort of flat or unmodified, unfiltered input into the radio, put audio in there, and it will transmit that. And yeah, they're a very good option if you want something that's all wider range, so for example what I have on the other side of the camp here. There's also the RASPager, which I believe is a project started by the same people behind DapNet, so this is just a pi add on board. As it is, it's good for a personal hotspot, or you can put it through a power amplifier, as per the photo on the right. Yeah, it's another option. I included it there because it's the third most popular according to DapNet in terms of what people are actually using. So yeah, in terms of the hardware that I'm actually using for the transmitter that I have at EMF, it's essentially similar to the photo from two slides ago. It's a Motorola GM 900 Raspberry Pi and what I've been accused of designing a very overengineered case. So yeah, you can see there, there's also a couple of, you can maybe just make out the blue PCB, also has a few relays on for things like turning the power off, which is a licensing condition. You have to comply with it, you have to be able to turn it off if something goes wrong. And there it is installed in the tent. It doesn't look like that now because the high winds might have had an interaction with the mast. So it's on its lowest sort of height now, although it seems to still reach most parts of the site fine, so yeah. So yeah, I now have many slides on software because as I said, I am a software person, so that side of things is very, very overengineered. So the most important piece of software is DapNet. This is the thing that connects, it bridges the radio with the paging network. So yeah, Unipadri is some software written by the people behind DapNet. It's, yeah, you can just take it and run it on a Raspberry Pi. It's, I do have to maintain a fork of it because of, so the way the, if you're just running a Raspberry Pi on the Pi, it's fine if you want to run something a little more resilient. That doesn't mind power being yanked out from the Pi, such as Alpine Linux. It's a bit more of a pain, which is why I have to maintain a fork of it, but yeah. Yeah, there is also a sort of version one, version two sort of divergence in DapNet as well. There's the idea to replace the backhaul with this version two of the network. But that makes it difficult because version one is what's currently deployed. If you take the current version of the software and try and use it on version one, it doesn't work. Yeah, it's not worth, it's not worth the rambling to go into that, I don't think. So yes, more software. So yes, remote closed down, the metrics remote closed down are a couple of things I wrote. These purely licensed compliance things, they allow me to enable and disable the power to the radio remotely. And it also serves this quite handy notification if there's any power or networking issues on the actual transmitter side, which has been quite handy. It's notified me a couple of times of there being something weird happening with the power distribution. And yeah, it's quite handy. It just presents itself as a matrix chatbot. Sorry, a notification trying to do the phone. MQTT actor and MQTT rubic publisher, again to fairly small things I wrote. So this is what does the queuing of virtual. So MQTT actor is why I used to queue up the messages to be sent specific times. It's a fairly simple thing. You should have timestamp message and that's that's about it. It's all you need. MQTT rubic publisher that takes those messages and sends them as rubic content on Daphnit. Config generator is a very purpose specific thing I wrote, which takes the EMF schedule API and creates content to go into MQTT actor. In hindsight, this was not the best way of doing things because whenever the schedule changes, it's then a manual sort of process to rerun all these scripts and read by configuration. So if anybody's actually been looking at the event schedule as per Poxag, if it's been wrong, this is why it's been wrong. I do try and keep it up to date every day, but for some reason I thought the schedule would be as fluid as it has been. So yeah, I think in the description I did say this talk would be a mix of things that worked and things that didn't. Everything I've said now has been the things that have worked. Now we're on to the things that haven't. So I did sort of loosely promise a firmer for these ttgo slash t-beam law reports because these have a RF chip on them that has inbuilt FSK decoding. So in theory, it should be fairly easy to get those to decode Poxag. They also have no LED display on the back of them. They have an 18650 battery holder. So yeah, it would be quite an ideal thing to use. This is a very low cost pager, which yeah, is quite a bit more low cost than these, which I think the AlphaPock is probably one of the cheaper pages and even then that's about £50 or something compared to this, which is about maybe £30, £35 or something, or cheaper if you get the Samsung GPS one. But yeah, I essentially ran out of time to do this. Yeah, they seem very particular about getting the center frequency and the deviation correct, which didn't immediately work and I just didn't have time to go into it any further. I do want to make that work though, so eventually hopefully I'll get that done. I think that is all I had. So I'll finish on this slide, which is, so the top one is a link to the GitHub repository, which has all of the things related to the page and transmitter deployed at EMF and links to all of the other obscure little pieces of software I had to write along the way to make it work. If anybody wants to get in touch, ask questions, you can do so via the second link, which is my website. Although I realised I finished in about half the time that I sat underneath, so I guess there's no issue with me taking questions if anybody has any immediately. I've got a question myself, actually. Are pages still used nowadays commercially in context? They are in some cases. Yeah, I can't think of examples off the top of my head where I know certainly that they're still used, but yes. Are they still used in hospitals? Are they still used in hospitals? That was one of the big cases before, or have they been replaced there now? Yeah, so I believe they are. I'm not certain exactly the specifics of where they're used, but yeah, I gather the NHS might still be somebody. Does anyone else have any questions? Lucy, do you want to throw the microphone over? So the one at EMF, this uses 439.9875 MHz, so that's kind of a standard frequency for Daphnit. There is on the Daphnit Wiki a list of the frequencies used per country. It's typically that countries will sort of settle on a standard frequency. For most of Europe and the UK, it's in the 77s band and 439.9875. Some countries use a frequency in the doomate band, but yeah, I think most countries that have Daphnit transmitters use 70s. So, could you repeat that? Was it when you want Europe to have one? I think it, yeah, I guess the shortest answer is it depends. So some, again on the Daphnit Wiki there's a list of the various pages that are known to work well. There are some that can be easily modified, so I think some of the skyper pages for example, I think you can do a crystal swap to change the band that they work on. I've never done any of that myself. I've just used the other things I've ever used with Pogsack are the Alpha Pog, which is on the right band and you can change the frequency anyway and SDRs. I've never had to do a hardware mod to a pager, but yeah, there's a community out there for people that have, so it's worth, if you've got them on a lump of the pager, just have a look on the Daphnit Wiki and see what they say. I think there was a question at the back. Ah, so a question, okay, that's easy. Any other questions? No? Okay, if anyone else has any questions, do feel free to ask later. Otherwise, thank you very much, Dan, for explaining pages to us.