Buying Snacks via NFC with GNU Taler
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Transcript: English(auto-generated)
00:06
Okay, everyone. Welcome to our next talk, Buying Snacks via NFC with G&U Tala or Gnu Tala as I think the better pronunciation. Our speakers are Dominic and Marco. Please give them a warm round of applause.
00:25
So we came here today to tell you the story. Fred was hacking all night when he realized that he was really hungry. So he went to the next snack machine and just realized there that he has no coins left.
00:45
He didn't want to share his private data with paying by his credit card. So if you can relate with Fred, then maybe we have got the solution for you. We implemented the software for a snack machine running
01:01
a Gnu Tala payment system where you can pay with NFC. If you don't know what Tala is at this moment, don't worry, we will give you a short introduction later. But first, let me introduce you to who we are. My colleague here is Dominic.
01:21
He has finished his bachelor studies at the Burn University of Applied Sciences in Micro and Medical Technology this year. I'm Marco. I am studying Computer Science also at the Burn University of Applied Science. So you can imagine us as two students,
01:44
the first time diving into embedded development and we did not know what Tala is or what MDB communication is. When we got this project from our supervisors and Christian Grothoff, who is developer from the Tala payment systems
02:02
and also a professor at the Burn University of Applied Sciences and from Andreas Haubechter, who is not here today, but he gave us the lecture in embedded Linux. So what is Gnu Tala?
02:21
Gnu Tala is not the new cryptocurrency because you can pay in existing currencies like euros, US dollar or even Bitcoins. And the developers call it privacy preserving because you can spend money without sharing your private data.
02:43
And they call it practical because you get the comfort of digital payments but you also get the privacy of cash. And it's legally compliant with all these futures because it has to be compliant to the money laundering law.
03:03
The state can visit, the income of a merchant is visible to the state. But if you want to know more about Gnu Tala, please visit, oh, that's wrong, sorry. Just how Tala works.
03:24
You as a customer, you have to create an account on the Tala website exchange and you have to download the wallet on your mobile phone or on your browser. Then you can tell your bank to found this account with your currency,
03:43
which then will exchange to Tala coins and you can withdraw them to your wallet. If you got these coins on your wallet, you can go to some merchant and spend them there. And the merchant has tend to deposit the coins again on his exchange
04:01
and will get the money in his currency on his bank account. But if you want more detail about Tala or yes about Tala, please visit tala.net or ask Christian or the other Tala crew at the stand.
04:27
So yeah, no. What was the project? So we had a project in the embedded Linux course and the motivation behind this
04:40
was to build a easy to use Tala demonstrator to demonstrate the Tala payment system. Yeah, to give the capability to buy real goods and stuff to a customer by using the Tala tokens because before there were just the demo applications
05:04
and then of course doing a cool project for our courses at the Berne University of Applied Science. Then what were the goals? To integrate Tala API in a embedded Linux environment
05:22
so we implemented, we tried to implement interface between the Tala backend and our hardware, the snack machine. Then the integration of the communication protocol which is supported by vending machines.
05:42
That's the MDB ICP protocol which was developed by Coca Cola and is now a worldwide standard for the communication in vending machines and then of course building a prototype based on the Tala payment system
06:00
to show it here at the 36 C3. And the vision, yeah, of course increase the awareness of the Tala project worldwide and to industrialize a prototype in future steps.
06:20
So what was the concept? Here we have the Tala backend. For us this was like a black box so we had Christian who made this with his developers and we had just this REST API to communicate. Then we took a computer
06:43
and we implemented the interface with the snack machine and an interface to communicate with the Tala wallet via NFC. And the idea was to give the ability to the customer to choose a product on the snack machine,
07:02
then get the information about the product, make an order in the backend, sell it via NFC to the wallet of the customer and to check if the purchase was confirmed or not and then to send this information again
07:21
to the snack machine and to deliver the product to the customer. So how was this done? Yeah, we got a lot of hardware to get this task done. We had some MDP converters, a display, an NFC reader, a test bed and a computer or a Raspberry Pi
07:44
and we had to pull all together to implement our prototype. What we have used was a Raspberry Pi 3P Plus. We decided to take this
08:01
because we used it in the course and also it is easy to use. For fast prototyping and for fast development. Then we had a MDP-ICP converter from Shanghai Wifer Microelectronics
08:22
which we used three different products or we tried to use but this one was the easiest to implement. So we decided to take this one and then we had a test bed for the MDP communication that's just a simulator for a vending machine
08:44
and we got this from Braunmann Auke in that's a small company in Switzerland. Then of course we had the NFC reader which is connected via USB to the Raspberry Pi.
09:00
And finally display and we decided to use a display to show a QR code because not every smartphone has an NFC implemented.
09:21
How does the software look? Like you have seen before, we use the Raspberry Pi and our software is depending on internet because Taler really uses an internet connection. So if you come to our snack machine please don't worry if it's not loaded quickly.
09:42
On the Raspberry there is running a Raspbian Linux and for our software we use the GNU net libraries and the LIP NFC for the NFC communication which sometimes maybe will be replaced with a better one and we use LIP QR encode to encode the QR codes
10:04
to pay the goods. And we also use LIP Taler. In our first tries we tried to implement the communication with Taler ourselves via LIP curl but then we realized that Taler gives us the interface
10:21
to do it a lot easier and we were much quicker. Yeah, I think that if you want to know more about the source code as it's open source you can have an insight that the Taler repositories. And yes, if you imagine us, we had a lot of hacking
10:44
and a lot of hardware, a lot of box and finally we threw it all into a big funnel and our snack machine came out. But that was not easily done and we had a lot of challenges on our way.
11:04
So we had to do a bit of magic and what were the challenges? I think the biggest challenge was the MDB converters because they are not open. The MDB protocol is a proprietary protocol and so the vendors of these converters
11:24
they want to make money so they don't offer us the hardware implementation so it's a bit of black box. And then also of course the software of the snack machines is not open source so you have to figure out how you can communicate with them
11:41
and the MDB standard differs from vendor to vendor. So we talked also with a vendor for coffee machines and he said they have also a lot of problems to implement this MDB protocol because it differs from vendor to vendor
12:01
or from snack machine to snack machine. So we had there a lot of problems. Also today we were hacking the whole day to get this application working. So what is the project outlook? We want to offer the internet over the NFC
12:23
if you have no internet connection on your phone. Then we have a bachelor thesis in the next semester at the Bern University of Applied Sciences where the goal is to develop an embedded hardware
12:41
which can convert the MDB ICP protocol to a normal serial protocol and also implements the computing unit. Then the snack machine gets exposed and at the World Economic Forum, the web in Davos in January
13:04
and finally after the web, it gets installed at the Bern University of Applied Science in Biel to give the ability to the students to buy snacks and other stuff with the taller payment system.
13:21
So there is also a lot to do and yeah. Yes, now how does it work at the 3063? First you have to download your wallet to your mobile phone. You can do this via the Play Store
13:42
or with the link at our stand. Then you have to come to us where you can come to me or to my colleagues and exchange your euros to taller coins which you can withdraw to your wallet. When you have withdrawn these coins,
14:03
you can have fun and spend them on our snack machine. If you remember Fred from the beginning who was hungry and angry at the same time, so now he's lucky because he can pay his food
14:22
with taller wallets and pay with his smartphone via NFC or via QR code and so I hope it will be the same for you when you come and visit us at our stand. Yeah, thank you for your attention
14:40
and if you have questions, I think we have no time for a few. Thank you, now we have 10 minutes for Q&A. I have a question, where is your stand? Where is the vending machine? Okay.
15:01
So yeah, right over there, I think it's the second or third boat from here. Okay, so you have a question? Can you, can someone give him the microphone please? Oh, test, test.
15:38
Also just yell it and we will repeat it.
15:41
Okay. Come to Reinfach here. Yeah, not a question as much as a couple more remarks. First of all, you cannot just buy stuff at the snack machine with this. You can also donate to the Center for Tech Cultivation. They've set up a webpage, which you can access
16:02
via buywith.tahler.net, which we'll link to it and if the Warholand Foundation gets their act together, they'll have a second webpage where you can donate with Tahler online. So you can use your mobile phone to do online payments as well and I should mention, this is not for profit. Any money that you lose, as in you didn't spend in a wallet or any profits we might accidentally make
16:22
by the whole thing, will be donated to the Digitar Gurage. So don't be worried about losing money with this. It will all be going for a good cause anyway. Thank you. Any other questions? Does the internet have any questions?
16:41
No? All right, I will give you a few seconds to collect yourselves and come up with some more questions. Or do you have anything else that you want to tell us? Yeah, just visit us at our stand.
17:01
There you can ask some questions. Yeah, you have some more after and yeah, buy some snacks, have fun. Okay, please give our speakers another warm round of applause.