LoRa experiments in Plovdiv

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We are working for some months on OSHW LoRa nodes and our goal is to bring up free to use for non for profit Smart City solutions LoRaWAN network which to cover city of Plovdiv .

Yesterday we installed our First LoRaWAN Gateway made with T2-OLinuXino-LIME2-e16GBs16MB + RK831 + +6dBi rod antenna on Rilon Building which is about in the city center and with height good for antenna installation.

You can see on above map – the “Raspberry Pi” is hardcoded in RK831 firmware but do not worry there is industrial grade Linux computer in the gateway.

 

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We start experimenting with our LoRa868 and MOD-LoRa868 modules and made portable GPS tracker device like this:

LoRa-GPS

The results are nice. We cover almost 2km circle around the antenna. With few spots which are shadowed by tall building.

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The secret in the big distance is the good gain gateway antenna!

We really are impatient to release these LoRa gadgets as soon as possible, but unfortunately it takes much more time than we expected.

There were lot of issues with the Semtech/ARMmbed reference designs like the RF part of their 868Mhz design actually has components values which make 915Mhz device and vice versa. We spent weeks to understand why the communication distance is not as good as expected, before we realize that we use 915Mhz LoRa nodes with 868Mhz antennas! Once we get everything complete and tested will put our boards on the web for sale and publish OSHW their correct schematics and component values, so other will not waste their time like we did.

One issue we encountered with RK831 Gateway is that it freeze from time to time when receive malformed packets and need to restart. As RK831 firmware is not open source we can’t debug the cause of this problem. The workaround now is when host lose connection with gateway just reboot latter. Really not most elegant solution, but so far we can’t do anything else.

We are preparing two more Gateways to install in the next days, which will cover more parts of the city.

 

 

FOSDEM slides and video

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FOSDEM is always impressive, even for people like me who go there for 7th time. It’s great place where you can see developers for almost every FOSS big project and talk face to face.

It’s really pleasure to see that last years there is Hardware related dev rooms too.

KiCad as always attracted lot of attention

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but CAD and OSHW devroom was pretty small, so people are waiting on long tails to get in and just few lucky ones succeed:

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For security reason the organizers didn’t allow people to stay standing or sitting on the floor, but this didn’t stop all. Next day I spoke to lot of friends and they said – I knew there will be no space for all who want to enter, so I just stay at the cafeteria and watched the stream.

It was same situation at the Andre Przywara talk One image to rule them all. There was no space in the room to accommodate all people who wanted to attend it.

There were three talks from Plovdiv at FOSDEM this year 🙂 Our friend Leon Anavi had two talks Making Open Source Hardware for Retrogaming on Raspberry Pi and The Software Developer’s Guide to Open Source Hardware. It’s cool as his full time job is as software engineer but as you can see he does OSHW in his free time and obviously like to talk more about his hobby than his daily work 🙂

I talked about some new OSHW boards we are working on last few months.

The idea is to build LoRaWAN infrastructire and install some free Smart City solutions in Plovdiv which to set example and to put all our work on GitHub so if other cities want to follow to be able to replicate and scale what we did and hopefully people to get aware more about the power of the open source hardware and software solutions.

Here are my slides and here is my attempt to speak English at FOSDEM. Sorry subtitles are not available 🙂

It was incredible pleasant surprise to see OLinuXino-LIME2 mentioned in Danny Haidar‘s lighting talk Creating a Computing Revolution: from Personal Computers to Personal Servers.

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NB-IoT seminar slides and BC66 datasheets are online

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NB-IoT seminar by Quectel and Comet had more than 130 peoples interested. The hall was full even with people not having place to sit.

It’s understandable as NB-IoT is one of the fastest developing technology.

NB-IoT is new, the standard draft was made in July 2015 and at the beginning of 2016 already has been accepted, just in 6 months.

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For comparison LoRa is technology from 2008, but just last couple of years people start using it widely. The other LPWAN Weightless was announced in 2012 but first ever devices were made in July 2017.

Why NB-IoT was developed so fast?

Because Qualcomm, Vodafone, Ericsson and Huawei which are major player in mobile networking are behind it. NB-IoT works with the existing cellular network base station hardware. In practice it’s lightweight LTE implementation and just uses narrow band communication. So to add support for NB-IoT only software upgrade is necessary and it uses the existing infrastructure.

Another boost for NB-IoT is that it was first choice for IoT implementation in China as product with Chinese company (Huawei) involved vs LoRa which is considered technology controlled by US company.

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According to Quectel slides they sold in 2017 36 million modules for about 245 million USD i.e. average price per module is USD 7 which is already in LoRa pricing range.

NB-IoT though offers lot of advantages compared to LoRa. The Narrow Band communication allow the receiver sensitivity to increase many times and with one base station is possible (from the slides) to cover up to 100 km with NB-IoT. Also one single cell base station can serve up to 100 000 NB-IoT nodes!

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Quectel flagman for NB-IoT is BC66

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It’s Multiband: B1+B2+B3+B5+B8+B12+B13+B17+B18+B19+B20+B25+B26+B28+B66 i.e. covers completely all regions US, EU, Asia, Africa, Australia and once you do your design you can scale worldwide.

Anothe major advantage is that it works from 2,1 up to 3.6V. This is very important as Lithium batteries capacities usually are defined when battery is discharged from 3.0 to 2.0 V.

NB-IoT is different from 2G/3G where there are 2A pulses when link to base station is eastablished, here max current drawing is only 250mA when you establish link to base station. Once established link do not need to be re-connected when the module go to PowerSavingMode and wake ups!

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This is why their recommended design has just 100uF filtering capacitor necessary!

Another nice surprise is that in BC66 you have Cortex-M4 78Mhz ARM processor with 400KB Flash and 400KB RAM running FreeRTOS, which you can use for your own applications. There is also ARDUINO support:

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Overall BC66 seems very interesting and we are dedicated to release OSHW boards with it targeting same applications like with LoRa: Smart metering, Parking, Smart City, Industry 4.0 etc.

Who ever have dealt with Chinese vendors know how they hide all info from their potential customers, in this regard Quectel made difference by releasing all BC66 info online after the seminar. You can view all presentations and the datasheets here.

 

PlovdivConf 2018 is this Saturday!

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PlovdivConf is part of IT Tour great initiative, to make regional IT conferences in 5 big cities in Bulgaria: Varna, Burgas, Ruse, Veliko Tarnovo and Plovdiv. They make it every year and it’s made by the same team which organize the biggest Open Source event in Bulgaria – OpenFest in Sofia.

As Open Fest is huge and there are usually more talks applications than time (OpenFest is just two days)  IT Tour decided to make these regional conferences where local people has more chances to talk on IT subjects.

This year I will have lecture at PlovdivConf and will talk about “How Open Source technologies can help to make our city better place to live”.

Plovdiv municipality recently show interest in Open Source and we will try to help with our expertise and experience. The initial subject they are looking for solutions are: Parking management, City Lighting management, Waste management, Transport management, Bicycle management, and so on. We are already working on FOSS/OSHW solution for all these problems. They are open though to any other subjects which could help them to do their job better, so if you have idea come and share.

In my talk I will try to show the advantages of the Open Source solutions. Everyone is welcome to join the conference. It’s free to attend and we will looking forward to hear you and have after lecture discussions and ideas exchange how we can make our cities better place to live.

 

EDIT-25.09.2018: I’ve just uploaded the translated to English slides on Slideshare. Please pardon errors it was done in no time 😉