Open Research Institute Weekly Reports, 9 Aug 2022

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From YouTube: ORI FPGA Meetup 9 August 2022

Description

MQTT approach to controlling the downlink circuits.

A

Hello: everyone welcome to the 9th of august stand-up meeting for fpga work at open research institute.

A

How is everybody doing today we're going to talk about what we've done over the past week or so, and what we have planned to do over the next week if we need any resources and if there's any roadblocks in our way, all right? So why don't you start us off ever east hello and welcome.

B

Hi everyone: um I see that there is a lot of improvements, so it's good sorry, I'm mainly in holidays, and I follow all the all the stuff from far but it seems okay.

B

I have few questions about the next steps, but uh hope that everyone is okay and uh wait. Maybe, for sum up before asking my question back to you,.

A

All right, thank you, yeah, looking forward to talking to you all right, james, tell us how it's going in remote lab south.

C

uh Things are going fairly well here, lab south uh we're getting closer and closer to our gigabit fiber internet we've gotten all the connections like towards the building and then in the coming weeks. We're gonna have someone come by and do all the detections within the building, which should greatly improve connectivity to remote lab sound.

C

uh On the grants side, though, I might save that for the other meeting we don't have nearly as good news, but I'll just say, leave that for the grants meeting that comes after this stand up.

A

Okay, very good, and I think, we're still working on getting the roof and the internal electrical settled. Is there anything that you need for that for for the build out of the physical plant.

C

um Nothing currently we're getting the we're just continuing on there getting work done.

A

Oh okay, yeah, the fiber is, uh is really good news. That'll help with the all sorts of things, not just the equipment at the workbenches, but also what we're talking about doing is interferometry site and that's gonna need some high speed uh connectivity so very much looking forward to that. All right and ancho uh go ahead. You have the floor.

C

Hey uh nothing much to report, I'm just working on the next step to get the dma working, uh psbl communication and uh so looking at some samples and what all registers to use what I'm config and also simultaneously is telling the code that everest has shared for mqtt.

C

uh It looks like a good framework for doing the testing so simultaneously also working on that yeah. That's me.

A

Okay, cool all right I'll talk a little bit about what I'm, what I've done so um mainly if you can see on slack I've. I've been told by the uh the people, the nice people at engineer zone that the framework that we use, like those yakto layers with the core and the xilinx that actually gives us the thing that I was trying to install with the api download.

A

So when you install or when you download the api uh from from analog devices, um which sets up a directory structure with app and an api and there's an example code, and then then you export the um some artifacts from the transceiver evaluation software, which gives you all the things that you need to set up your transceiver. And so I thought that's how we use the the linux driver. Well, it turns out it's already in there with the octo layers.

A

So well, it made me feel a little bit silly, but but okay, and so I backed up and I'm like okay. So all of these calls should be there, and uh that's that's where, where I'm at so so, don't need to do anything extra, don't need to download anything or compile anything extra. We should be able to it, and I double checked it's the exact same uh dts that we install when we walk through our procedure to get to the application layer so we're on the right track.

A

I just was doing a lot of extra work. uh Mqtt sounds amazing and I think eva reese has some some some questions about next steps and what we want to accomplish.

A

I think what we want to do is to to transmit over the air with uh dvbs2 frames, um and I think we're set up to do that, um and we should probably talk about that next, so I'm going to be quiet and let every east ask questions or um or on, shall you ask questions or to let's talk about how to get on on the air, because I think we're we're ready to do that.

B

Yeah. Okay, so I said that you fixed the issue with the address of the pl. um I think that now all is running okay from sorry from the fpga side, then, on the ps side, then you have the example of the brittle using mqtt.

B

um So the main modification is to uh to set the right channels, which means that I think that you use and you have installed io on the on the zinc and then there is just some uh string.

B

uh Access to uh ericsson takes well the the right takes path in order to uh uh to set it for the for the special dac you use um it's. I think it's not a big modification. So if you have some question about that, I can easily answer that. uh The my main question is michelle: using is used the tes software, but maybe it's another experience not dedicated to dvbs2.

B

Just wondering why using that uh for now. But uh if you have question, uh let me know.

A

Yeah, I think we have lots of questions um so yeah the tes, the transceiver evaluation software. uh What it does is when you run it you, you use a gui, so use a graphical user interface to set up the uh 80, the 9371. So so you can set up your the bandwidth and the frequency and the filters. You can actually go ahead and set up your transmit and receive filters and your clock regime. So you can do all of that in a relatively easy to use way, and then you save out the script.

A

So you save out c files and those c files have all of the calls to the api um from analog devices that will walk through waking up your transceiver and setting it up, and so I thought, oh well, okay, that made sense um from the old fashioned or the the you know the api of source code, um and so it turns out that all this work that we did in order to get. I o well that that's what iio uses under the hood.

A

I don't need to make the like the I don't. I don't need to actually call all that stuff. We still need to set it up, though um at least that's what the uh instructions say on some of those web pages so and also in some of the forum posts. So it looks like even though I we don't need to pull in the entire source code of the api, uh that we still need the to do the same sorts of things that that you, you still need to set up your transceiver.

A

You still need to configure it, and- and that's where I'm at so I asked uh on the engineer zone and like made sure try to try to make sure like. Is this really do we really need something from tes still or is it all set up for us in iio in these layers, as I was hoping to be able to figure that out yesterday, but it today is the last day that I'm here before leaving for def con we leave tomorrow morning. So these sorts of questions might be answered next week at the earliest.

A

uh So so, just just letting you know where I'm at, um but the the strong recommendation was to go ahead and use the iio in these. These layers that we already have working um and and how to actually write like how to use them. So I'm looking for like where's the definitive set of calls that I use these are higher layer. The iio is higher layer than what I was. um What I was using so the source code for the api, that's all built into io, that's what I use is at a lower level.

A

So, once again, my my background is, uh like you know, assembly code and writing directly to registers, and I'm always assuming that's what I have to do, but but in the modern fpga world you don't all of this stuff is is abstracted for us. If we can just figure out how to get it to work, um and so I think we all we have it now. I think it's actually working on the zc706 on the adrb 9371 and it's just going to be like.

A

Oh you know, here's the list of function calls here's what you can use. I think that's anyway, that's where I'm at um and I'm I'm I've used mqtt once before for a simple project on a uh particle I o board.

A

So if there's, I know that the pluto uses it and and functioned uh and was working over the air with it with mqtt. So I think that's probably the the best path forward is if we can get something transmitting over the air in the lab using the code that's already written for the pluto, I think that's the best path forward, all right back to you.

C

B

C

Sorry, you want to go ahead.

B

Yeah just I, I just understand that the tes is a more parallel parallel way of setting the register of the adcdac.

B

It's recommended if you run no eos.

B

So if you don't sorry, if you don't use linux and neither io as soon as you have linux on io, I think that the best one the easiest easiest way is to use. I o directly.

A

Oh okay, so I do. I don't have to use the that output stuff from tbs.

B

I don't think so.

A

B

A

That that helps a lot.

B

But maybe maybe there is uh some other tool in tears. I I I I didn't know it uh before. uh Maybe there is some. um uh I think that that there is some ncu or something like that, which means that maybe there is some components included in the fpga. I don't know because normally there is no nc nco in the fpga design.

B

So maybe it is another platform where another um architecture api, but as soon as you use linux, I think it's not the the the target of tes. Okay.

A

Yeah, that makes sense the the way.

B

A

B

A

I was looking at this was definitely more low level, so yeah, okay, thank.

B

You the other way well the the the mqtt way I set it well. Normally there is no mqtt uh on the on the pluto, um but so you can, you can use io of a network or of a usb. Yes, you can send all the commands on that.

A

B

A

We've been able to use um both the pluto and the zc706 like when.

B

A

Bring it up with iio being able to use it as a remote station is really amazing. So so we.

B

A

See that happening.

B

That's that's okay, uh but um I set mqtt in order to uh have another abstraction and do not use the eye or streaming, which is a little bottleneck.

B

um So I try to have a very simple, a simple server, which means that on the clients you you don't have to have the live io on your clients, which means that uh right now on your pc, you need a live io to um to discuss with the server. I o from the platform right and using mqtt uh is another just a little abstraction on that, which means that you, you can do that even by don't know any io library, which means just sending some string over mqtt and uh and it's okay.

B

So there is some command which is directly patch from mqtt to io, and there is some command which means that, for example, uh if you write it to dvbs2 3, then it is the uh server well, it is the. There is some function on the um on the pluto or on the zinc, which respond to all that.

B

I don't know if it's very uh understable understable, but well um normally you you don't need mqtt. uh I do this because it's simple to order. It uh from different devices, um but I think it's a good uh a good base, and uh this mqtt server, which is done well, which is dedicated for the pluto, is easily uh could be easily adapted to uh the z6706 and.

B

It's just uh have to fork and uh and and uh send some I or string that differently. uh If I can have uh a remote um remote platform, I could easily adapt it also, but I think that and should do that if I can answer some questions about the code.

C

Yeah um there's uh I I did I I did study about this mqtt. So I have few questions. uh If we go into bit deeper, when you say mqtt server uh and we have empty mqtt, client and mqtt subscriber, then there are broadcast messages and messages. So when you, if I talk about setup, this mqtt server is some, is it? Is it some software uh because on I went to mqtt page and it said some softwares for clients, some software for servers? So what is mqtt server and where does it run?

C

Does it run on the ps side and what is it.

B

Yeah right now, um right now the mqtt server is, is on the yeah. On the ps side we can, we can choose to have uh mqtt server outside, which means that maybe on another pc, which means that uh on this pc on this server, you can have uh several, for example, dvds2 in caller, publish and request the message from that. But right now the the easiest way is that the mqg server is on the pluto, okay and and from your pc.

B

uh You are, you are uh mqtt client, so, okay, you you subscribe to.

B

uh um I need I need to decompose it, but as soon as the mqtt server is doing is running on the pluto, then you can mqtt explorer, for example, which is subscribing to all channels, and you can see all the status and that's the prito is doing, and you can easily write some topics, uh for example uh frequency sample rate and then for dbs to.

B

Typical, for example, the fec and something like that, and all that you can see it on the client on the mqtt client on your pc. So the uh if you, if you see the firmware uh there, is a mqtt server installed on the pluto directly and- and there is, um I think there is pluto controller on twitter stream process and the protocontroller is- is publishing to the mqtt server, which is on the pluto. But and so he publishing the status and the request and wait for the request.

B

Sorry, just just a minute.

B

Yeah sorry, some family calls.

C

B

um So yeah I can answer if there is more detailed questions. Sorry uh I don't know if I'm clear, that's fine! You.

C

Are yes so now uh I I see the uh link I went to the. If I go to the github, I see files uh various c files. One is for streaming, so if I have to install server and if I have to install client, so what are these? uh Is there a software or script or shall I compile the code? uh What are these clients? Okay,.

B

The mqtt server on the on the zinc side, the classical mqtt server, so you just have to install a mosquito.

B

You can you can see it on the uh on the bedroot side. uh It's a just a classical component. Okay. So just after that, on the what you have to modify is the well, it's called mqtt controller.

B

That's a client and so mqtt controller is a client yeah.

C

B

Yeah there is one server which is the mosquito server and then um the mqtt controller process is publishing some status and wait for uh some commands, for example, setting frequency and then the setting frequency when when well the the mqtt controller subscribe to uh frequency, for example, and when he, when he received message, he sent an io message: okay, internally, okay, so this is this message this I o message you have to modify because right now it is dedicated to pluto.

C

B

And- and it's just some string to uh to modify it's okay, there is no release um algorithm or well. It's just some string, because the I o have some trees with uh channel one two, three etc, or something like that and you just have to modify the stream. But I can point you uh where all is, uh while always sitting.

C

Shall I share my screen with your guitar or okay? Let me see.

C

Here and uh I can give you remote access- also.

C

So can you see my screen yeah yeah, so this is the wrap-up and so.

B

Yeah, so okay, this is um yes, yes, okay, so you have, for example,.

B

So um mqtt controller.

B

Should be mqtt and welcome.

B

If you go to mqtt okay, just let me see remember.

B

B

Yeah, if you go to so mqtt handle command dot cpp. So this above, no not this one yeah this one line: 7 6 50, something like that.

B

B

Okay, so now you have some uh just okay, you can see 769 command, eric's frequency, for example, yeah, okay, and so it's it's send.

B

um So if you uh uh well, the mqtt is receiving this message and send sysbus. I o device, ceo, etc.

C

B

Okay, so the this one should be adapted to uh you are a special eye or tree yeah. Okay,.

C

B

ah You have the eric's gain, eric's format and, and then you have the ticks and and all all the sis bus I or something should be adapted to uh to your particular iotree.

C

Yes, yes, yes, that's right.

B

Okay right, so this is the mqtt control which mean which is mainly for frequency and sample rate. Okay, okay and then there is the mqtt.

B

B

Which is mainly for streaming so, which is the dma based- and this is here very important.

B

Okay, try to remember.

B

uh It is a a process.

B

Which? Okay right from birth? Sorry, a.

C

B

Time ago I didn't do that. Okay, there is uh yeah uh line.

B

Like 900, something like that.

B

B

Okay, it gets some data from the yesterday in.

B

And write it to io.

B

And and for example, 900, you have some right buy from buffer burst and then there is some button so right now it is not used any std. It is some but test pattern.

B

I used to uh to test the fpga code, and so you can, you can see how it is done.

B

There is. A very important thing is to is the length of what you uh send to io, because the fpga side weight from frame length and the frame length is depending on the is, depending on the fec.

C

B

Okay, I think that well, we have discussed with shoto on that and I think that there is not enough documentation. Well, we have to detail how it works, but.

B

That's if, if you use this code it it should be okay but yeah, but we we need to. uh We need to document it uh a little more. uh This part.

C

Got you got, you got you right, okay and uh how you got the data. Do you do you have the file like you're uh right from file? So I I think if you are reading some file or you are providing input to std and basically I'm looking for bb frame sample bb3.

B

Yeah normally it's it is. It is some uh std file with bb frame, but right now there is a lot of comments and it is so important, so the bb frame is already done on, uh for example, on 9 30.. It's pattern, 2 3, which means fec 2.3, and if you can see it, it's just uh it's just a lens with some zero, but it's uh well a buffer with a with the right length. Only that.

C

I didn't get that, but uh I wanted to understand: do you have some sample bb frames uh in file or no actually.

B

It's it's not really a good bb frame, but it's some buffer with the right length of the bb frame.

C

ah Okay, okay,.

B

And there is the bb frame eater on the no. There is not a bb frame either it's as on the fpga to change the fec on fly. We have four bytes before the bb frame.

C

B

And these four bytes is indicated, the fec, for example, okay, okay and sorry, for example, the on the line, eight, eight hundred twenty.

C

B

You have part in two three, uh where the the first byte is uh x, 31, which means it is, uh as I remember, qpsk 2.3, fake.

C

uh So here you are forming the bb frame.

B

C

B

Well, it's it's not the baby frame, it's, but it's yeah, the it's the command to set the the right efficiency of the uh of the modulation and uh the bb frame have well the the you need to uh set the right length. According to this efficiency, fec.

C

Right right, right, okay, so here uh 825 829, so this is this is this is where you are forming just a sample: zero, uh a bb frame with zero bytes. This yeah.

B

C

Yeah you're right right got, you yeah got you absolutely that's fine. Now one more thing uh like on server. I can get this package mosquito, but for client side. uh So do I need to compile this and I will get up. I will get a binary that I can run on client.

B

uh This one is also running on the on the pluto.

C

uh I didn't get it sorry.

B

uh You need to compile that yeah.

C

Yeah and it needs to run on pluto.

B

B

Yeah, you need to run it on crystal because well I don't use live io. I use directly the file system, uh so you have sys bus, etc. So you need you. I use the file system of the io device tree.

B

Okay, so you need to yeah. uh This is the ps, so you need to run it uh yeah, I'm using.

C

On your thing and mosquito is also on the sync yeah and for client.

B

Sorry for the client.

C

Yeah uh for for client side, uh I will I need to get uh this mqtt controller package to be run on that that runs on the client right uh on the on the pc.

B

On the pc right now you well uh yeah, you just need a for example. Mqtt explorer is just a agnostic, mqtt uh sender, on receiver, and you can send some commands with.

A

So this is, this is there's applications that we need to have running on pedal linux. Then it sounds like.

B

A

Yeah, okay, yeah. We know how to do that. I think yep.

B

Well, I think it's similar to bedroot, so you just need to add the package mosquito server, mqtt server of mosquito and then and then you have a yeah. You have a server mqtt server.

A

Yeah and then that server allows us to command the the command the the hdl essentially to to to order it around.

B

Well, yeah um this: this server is just an intermediate between the.

B

The outside, which is just some mqtt command and status, and the io, which is just uh on the zinc side right.

B

C

And uh do we need to configure the server also? Is there any configuration file? uh Do we.

B

Need a very minimum configuration file, which means just.

B

I can't remember, but it's very minimum I need to uh to catch the bedroot one.

B

Okay, so I go to uh the pluto ori frm and then go to the confinger, zinc door and then search for mosquito.

B

Yeah mosquito there is okay, so there is okay. Very packaged mosquito is yes, and then I have some overlay. Maybe.

B

Mosquito: okay, there is one conf which is mosquito conf and.

B

It is okay, I just set the listener where the port listener the listener and the protocol websockets. It's very standard configuration okay. So it's done here.

B

I set it on the chat.

A

Oh, thank you. Yeah see it.

C

That means, if we are using iio, we don't need to set any dma registers, control status or set scatter.

B

C

B

Yeah yeah with io all the dma is already done on the driver.

C

On the driver side.

B

Yeah, so you don't need to set it by hand like you uh did all the all the dimi is um yeah. It is done on the driver already good, okay,.

C

And this mosquito, we can include it uh when, while we configure root fs, is it available as a package or shall I do we need to install it externally.

B

Well, this is a big route package, so I think that uh there is the equivalent with uh peter linux. Okay, yeah.

A

Yeah we'll check and make sure yeah.

C

Yeah, I think that's that's good amount of information to get us started and move forward thanks a lot everest. That's all from my side.

C

B

Yeah, sorry, I'm not a lot available on these early days with the children. So I try to uh follow you and try to help you, but it's very unheard of.

A

No, it's a huge help. Thank you very much, we'll we'll do all that we can to catch up and- and you know we'll meet again and um and hopefully show off some good progress and then, if you see something that we need to do, then you can tell us and we'll just keep working together like this.

A

Yeah big help, I think, we're in good shape, great awesome. Okay, any other fpga work or any other anything else that anybody needs or any other questions.

A

All right, thank you. Everybody we'll close the fpga stand up for today and we will look forward to the next time we meet uh should be next tuesday. After defcon there will be uh most likely a lot of things to share, um but a lot of us, I think angel will be uh in the lab, uh but the rest of us from from remote lab west will be traveling and and demonstrating the uplink.

A

So we will most likely have some good reports about what we need to do for the demodulator, the receiver side for the uplink, which will rely on the fpga as well, so that work is coming up uh so yeah see you see you next week.

A

Thank you. Okay, have a good defcon! Oh thank you. We're looking forward to it.

B